Paying The Price For ADS-B

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So here we are with a new press release from the FAA ADS-B program office about ADS-B now being available in the Philadelphia area, that aircraft with ADS-B will receive both weather and traffic information service, even PHL TRACON will use it for traffic separation at 3 miles even when the aircraft are more than 30 nm from the radar site. It all sounds great. Now, if only the press release said everything rather than only what the FAA wanted released.

Reality is that unless you are one of the very few aircraft with a Garmin GDL90 978 MHz Universal Airborne Transceiver (for about $8,000 plus installation) and the Garmin GMX200 traffic multi-function display (about $11,000 plus installation), you will not be receiving anything in the Philadelphia area. In the immortal words of Strother Martin in Cool Hand Luke, "What we have here is a failure to communicate!"

The game plan for the ADS-B program (with ITT as the wining contractor) is to install more than 1,000 ground-based transceivers (transmitting on 978 MHz and 1030 MHz) across the U.S. national air space to hopefully provide traffic (on both 978 MHz and 1030 MHz) by year 2013. That sounds great if your aircraft has those receivers (and displays) and you are within reception range. The problem comes when an aircraft that has a 1090ES transponder (for ADS-B out) tries to determine the whereabouts of another aircraft that has a 978 MHz universal airborne transceiver. Unless both aircraft are within reception range of the ITT ground-based transceivers (minimum 1000' AGL for both aircraft if 37 nm away from the GBT), then neither will see the other. Remember even the FAA has decided that aircraft that fly above FL180 should have the 1090ES mode S transponder for ADS-B out. All other aircraft should have the 978 MHz UAT for ADS-B out (and in). Since all aircraft are at 0' AGL at one time or the other how on Earth (or above Earth) will they ever see each other when beyond reception of the ITT ground-based transceivers?

But, there's more. Now supposing you did order now and to be the first aircraft at Cross Keys (17N), NJ airport to get ADS-B in/out with the 978 MHz UAT. You'll get free weather (less content than WxWorx through XM and only when high enough to receive the GBT, i.e. 1000' AGL or higher when at 37 nm away), free traffic (again when high enough to receive it 1000' AGL or higher) and you only spent about $20,000.

But your hangar neighbor decided not to be a pioneer. He bought an XM receiver and pays $30/month for better content than you are getting (and gets it on the ground). He also bought a Garmin GTS800 traffic advisory system for $10,000 and gets active traffic information (12 nm radius ±10,000') even when on the ground. With the $10,00 more that you spent for less capability, he'll catch up to your costs after only 27.77 years of his XM subscription for the better weather content.

And even better still, both of you have a hangar neighbor at Cross Keys (17N) who decided 5 years ago to get the Garmin GTX330 (not ES since it did not exist back then) Mode S transponder. He convinced himself that there is no way he would ever buy an active traffic system (back then $20,000) so he got the traffic information service TIS through his Garmin GTX330 transponder. Result is that he gets traffic information at about 141' AGL with the ASR9 from PHL (13.9 nm away), and gets near continuous coverage 250 nm to the south through southwest and all the way to Portland (PWM), ME with a 200 nm swath. And he paid only about $4,500 for this traffic information service. Sometimes it is the old technology that works better for some.

The idea behind FAA's NextGen air traffic surveillance is "cost-shifting". How can the FAA get 250,000 U.S. aircraft owners to put in (and pay for) $20,000 worth of equipment so that the FAA can start decreasing some of the 300 ASR7/8/9/11 radar sites? Two simple words, FAR 91. They simply make ADS-B out required equipment for any aircraft to enter class A, B, C or any airspace above 10,000 feet by year 2020. Now some of the naysayers have doubts that the FAA would function without any of 300 radar sites in the country. You are probably correct but the idea is for other departments (such as DoD or DHS) to pay for the operation, not the FAA.

I am a firm believer in getting better equipment for the job rather than just buying the most expensive hoping that it might at least do some of what you need.

Getting a Garmin GDL90 978 MHz universal airborne transceiver (currently the only product with TSO C154 and includes a C145a GPS) means about $9,000 and being able to receive traffic only when in reception range of an ITT ground-based transceiver, and perhaps another aircraft broadcasting on 978 MHz. I have yet to see one FAA policy saying if the aircraft has ADS-B out via 978 MHz the aircraft can get rid of its transponder. In other words Mode C or Mode S will still be required for a vast majority of airspace.

It makes sense to me then to get a Mode S transponder that will also output the ADS-B requirements. You will then be very conspicuous to the PHL TRACON, aircraft with active traffic systems would even see your tail number for positive ID, and of course you'll meet the requirements for what the FAA has for the next 10 years and beyond.

FAA's decision to use to different frequencies (978 MHz and 1090 MHz) will be as successful as the Microwave Landing System from the 1980s and 1990s. No other countries are using 978 MHz for ADS-B and in fact all have chosen 1090 MHz (extended squitter ES version). I don't like it when the FAA makes a very big planning mistake like this, but I dislike it even more when 250,000 aircraft owners are expected to pay for it.

Comments (168)

This is a nice analysis of the situation, thanks Paul.

Something that worries me is the FAA's move from "First come, first served", to "Best equipped, best served". One could easily see an extension to "Not equipped, not served" in the very near future!

Posted by: Al Secen | April 29, 2010 6:50 AM    Report this comment

The 98% of the iceberg you DON'T see is the eventual spread of ADS-B to all forms of transportation as a carbon tax metering device. How Garmin got to be prime contractor for cockpits without a public debate is bad enough. But if you follow the path of the money it does NOT lead to traffic safety, it leads to revenue and eventual closing of Class-B to General Aviation.

Posted by: Richard Herbst | April 29, 2010 7:23 AM    Report this comment

I'm not at all sure I understand either Paul's comments or the progress of nextgen, but I won't let that stop me from making a few (possibly completely wrong) comments.

First, nextgen is a long way in the future. To try to be an early adopter at this point means to spend lots of money for equipment that probably won't do what you want a few years from now.

Second, I understand the standards for ADS-B equipment were either very late in being finalized or still haven't been completed. This means the current equipment only reflects a particular manufacturer's interpretation of what the future holds. It also means there are very few (1?) vendors for the equipment. I truly hope the future holds a lot of competition between avionics vendors for both required and optional equipment. This may happen a few years from now.

Lastly, I am much more interested in traffic information than weather and the other neat features supposedly available with nextgen. As a VFR pilot I am very concerned with high density traffic areas just outside class B and C airspace populated by a bunch of other VFR pilots avoiding ATC. I will be happy to buy ADS-B equipment when the prices are more reasonable and the future compatibility of the equipment seem more likely.

Posted by: PAUL MULWITZ | April 29, 2010 7:26 AM    Report this comment

As soon at someone makes an App for the Ipad which includes TIS, NextGen will be obsolete.

Posted by: DAVID AFFINITO | April 29, 2010 7:46 AM    Report this comment


You got your facts wrong. Garmin was not the prime contractor for the Capstone project. UPS bought Apollo Avionics and had an interest in ADSB to improve their operations at their bases. They got the contract for Capstone in Alaska and the test proved the system would work. Later, UPS sold Apollo to Garmin.

Posted by: JOHN COLLINS | April 29, 2010 7:56 AM    Report this comment

All new light aircraft in China are required to carry a UAT and the Civil Aviation Flight University of China has about 100 UATs installed.

The congestion on the 1090 frequency is already causing issues with TCAS.

Posted by: Jim Ward | April 29, 2010 8:24 AM    Report this comment

John: You are correct: Garmin was not the contractor for Capstone; I never suggested they were, but they are using everything in their arsenal to fold their Mode-S into the architecture. Although Garmin bought the Apollo system from UPS, they buried it to protect their 530 market. Weren't you a little surprised to see that snappy piece of hardware disappear after it was acquired? Nevertheless UPS does have a functional version of ADS-B in operation. Could the presently planned architecture (ADS-B) publish its spec and invite competing contractors to make this affordable for GA? Occam's Razor says yes, but a significant pork channel would close.

Posted by: Richard Herbst | April 29, 2010 8:34 AM    Report this comment

Paul M - NextGen is an evolutionary program and has started deployment now: En Route Automation Modernization (ERAM - in the ARTCC's), System Wide Information Management (SWIM - everywhere), and ADS-B (everywhere) are three of the first NextGen systems to roll out. Many more changes are planned and the entire system won't be complete until 2025 or later, but it's rolling out now.

Posted by: Al Secen | April 29, 2010 8:36 AM    Report this comment


The ADSB specification is published. What is not published is the FAA rule requiring its use. The NPRM is expected to be available mid month in May. There are several low cost solutions starting to show up in the market. Trig has a mode S transponder with ES for about $2500 that plugs into an existing KT76A slot. Navworx is progressing on a TSO'ed version of a UAT for around the same price. The Garmin GDL90 UAT is an obsolete product and I would expect that there will be announcements for low cost replacement products before the end of the year. IMHO, it is still a little premature for installing this technology, as the choices and new entries into the market will accelerate over the next few years.

Posted by: JOHN COLLINS | April 29, 2010 8:44 AM    Report this comment

ADSB will more than likely take the white elephant path as mode S took. Pay all that money for mode S and then the FAA dumped it and we ate the cost of the transponders. This is way to much money to get stuck with holding the bag.

Posted by: Unknown | April 29, 2010 9:04 AM    Report this comment

You and others do a diservice to the proposed ADS-B implimentation. I have flown with it since it's inception and would not want to ever fly without it again. It all seems to be about cost with everyone, yet back in the 70's when transponders were mandated for certain airspace they cost about $2000.00 to equip. Now almost 35 years later everyone is balking about the new prices for ADS-B which, when considering inflation is not too much different. Look at the cost of new airplanes in that time span. What you could buy for $8000.00 (new PA-28-180) now costs around $200,000.00 or more for the same airplane. ADS-B is the first thing (so far) that I have ever see the FAA go forward with full implimentation without changing or cancelling the program mid-stream. I am sure the boxes will become less expensive as time goes on and then everyone will love the system as I do. The weather and text info provided will improve also, and don't forget it's free and provides more than enough info for decision making in the cockpit.

Posted by: Joseph Blakaitis | April 29, 2010 9:07 AM    Report this comment

Too many black helicopters for me.

Posted by: JOHN COLLINS | April 29, 2010 9:08 AM    Report this comment

The fundamental problem with ADS-B is the cost of the transceivers. MITRE has developed a low cost ADS-B UAT transceiver with a parts cost of under $400 using consumer grade GPS and communications chip sets originally designed for the automotive and cell phone markets.

We have been trying to get the FAA to create certification standards for this class of avionics so that it can be commercialized for the GA market for VFR use. MITRE and the FAA are planning to flight test this technology in the DC area this summer in conjunction with AOPA and the Soaring Society of America to demonstrate its potential to improve the situational awareness for GA pilots.

If we can get the green light for commercialization, you will see ADS-B equipment widely available for the GA market in the same price range as currently available PCAS units, with much better performance, accuracy and functionality.

Posted by: Mike Schumann | April 29, 2010 9:31 AM    Report this comment

I'm not going to equip until this mess gets sorted out - sounds just like the 406mhz ELT's - as the deadline approaches the price will drop. The slide in 1090ES transponder sounds pretty good to me, although I understood that the GDL-90 would also display traffic and wx on a Garmin 430 WAAS box - am I correct?

Posted by: Josh Johnson | April 29, 2010 9:47 AM    Report this comment

As an Avionics Manager, and Technician, as well as a fellow pilot, the "idea" of ADS-B is all well and good, but, it doesn't really show any cost benifits to the aviation industry. You want safer skies, that allows for greater congestion...then stop killing the GA pilot with adding equipment requirements that add very little in the way of situational awarness. Avionics are expensive enough, without mandating systems that are even more expensive and add very little help to the pilot. If you really want to do something benifical, help the pilots and operators financially place todays avionics (TCAS, TIS-B, 406ELTs, WAAS) on board their airframes, and watchs the skies. Bottom line, this ADS-B is a politcal way for the FAA to pass the buck off of their shoulders and onto the people the serve...Or rather "service"!

Posted by: Joshua Honey | April 29, 2010 9:48 AM    Report this comment

Mr. Johnson,
You only get a portion of the traffic information displayed on the GNS-430W. The GNS-430W is the source for the GDL-90's GPS present position relative to the the traffic detected. A MFD of some type is required to display the rest of the information provided.

Posted by: Joshua Honey | April 29, 2010 9:51 AM    Report this comment

I can't dispute any of the facts presented in the article and I would agree that the best deal currently for a GA aircraft owner wanting traffic info is a Mode S TIS transponder. There are too many issues covered in this article to comment on all of them, but the argument made by the author is kind of like arguing TCAD was over priced and not terribly useful before a transponder mandate was implemented.

Show me another single receiver that will give you air-to-air traffic, non-ADS-B traffic uplink and Wx uplink. UAT was specficially designed to make transceiver (combined transmitter/receiver) almost as cheap as a transmitter alone. If you have to equip with the transmitter, adding the receiver to gain those services will be a deal hard to beat when the infrastructure is in place.

The intent behind Wx on UAT/978 was to add value to a piece of avionics you'd equip with any way. Mode S/1090 cannot support such a service and frequency congestion problems along with any associated services will get worse as ADS-B and TIS-B are added.

The display cost issue is the same for any flavor of ADS-B. The fact that the only UAT avionics configuration available right now is $8k for radio, plus $11 for MFD is a bit of an apples & oranges comparison. If you can display XM Wx on a hand-held GPS, you can display UAT Wx and traffic on a GPS hand-held. The manufacturers are just waiting for the demand to develop be for investing development dollars.

Posted by: Douglas Helton | April 29, 2010 10:52 AM    Report this comment

For a broadcast based technology, the FAA's "solution" of using two frequencies seems nuts. I think it's much more important to "pick one" than "which one". 1090ES is much easier path to go down. Why build out a bunch of ground stations that merely take in UAT and output 1090ES and vice versa so that each type sees the other? How exactly does that save frequency bandwidth?

Posted by: JON CARLSON | April 29, 2010 11:05 AM    Report this comment

The problem with 1090ES is the extremely limited bandwidth. This causes lots of problems in high density airspace.

UAT solves this problem completely. Life would have been much simpler if the FAA had standardized on UAT, at the cost of requiring dual UAT / 1090ES equipage on aircraft flying internationally. This would have been a lot less expensive in the long run vs. the current Rube Goldberg system, given the potential to have fully functional UAT hardware available for $1-2K, if the production volumes get high enough.

Posted by: Mike Schumann | April 29, 2010 11:27 AM    Report this comment

re: "The problem with 1090ES is the extremely limited bandwidth."

I understand this, and don't really disagree. However, how does having a GBT, which takes UAT signals as input and then broadcasts them on 1090ES so that the 1090ES aircraft can see them, reduce the bandwidth use? If one aircraft is broadcasting on 1090ES, it doesn't seem like it would be any less bandwidth to have that same aircraft broadcast on UAT then get rebroadcast on 1090. Hmm.

Given the political infeasibility of forcing the airlines to all move to UAT, it seems to me that just standardizing on 1090ES would be significantly easier, cheaper, and better. Then all aircraft can listen for each others' broadcasts directly, rather than relying on ground equippage to see those on the other frequency.

Posted by: JON CARLSON | April 29, 2010 11:42 AM    Report this comment

Supposedly Europe is going the 1090ES route - I have no idea what Canada is doing - but this is bigger than a US mandate, it's a worldwide issue. I think it's time for the ICAO members to get together and make up their mind so we can pick a system and go. I'd like free traffic info, but if I can't leave the US without 1090ES, that will be my choice. I'm sure not going to install both!

Posted by: Josh Johnson | April 29, 2010 11:52 AM    Report this comment

Also, what ever happened to the transponder "repeater type stations" that the Feds are installing in the mountainous areas? Sounds inexpensive to the feds. I kind of like that idea, and I'd really prefer to keep my KT-76a, thank you very much.

Posted by: Josh Johnson | April 29, 2010 11:54 AM    Report this comment


The GTS800, like the GDL90, has no display of its own and requires either the 430/530 or the GMX200 to display the traffic. So its effective price is the same as the GDL90.

Ditto John Collins' comment on the final rule due out in a few weeks--we don't know if the 1090ES mod to our GTX330s will even be allowed as a viable "out" function for piston traffic below FL180, so it's too soon to install that just yet. (The rule may mandate 978 MHz in order for planes to be compatible outside major metropolitan centers)

What I'm not seeing is the installation schedule for the Ground Based Transmitters (GBTs) to let 1090 "HD" talk to 978 "Blue Ray" (or VHS vs. Beta, take your pick) It's annoying not to be able to plan for when the system will be installed in my area. I actually asked the FAA and they had no clue.

But as to people thinking the UAT will cost a mere $1000 guess again. The UAT (or 1090ES, for that matter) requires a certified WAAS position source and that, most likely, drove the cost of the GDL90 so high. Don't count on a aera to be able to do that.

Posted by: David Rosing | April 29, 2010 11:59 AM    Report this comment

The WAAS requirement is one of the key factors that is making ADS-B unaffordable to the GA community. We are starting to get some traction with the FAA on the argument that WAAS is overkill in a VFR environment. If you have non WAAS equipped aircraft, you just need to a wider separation standard.

This may mean that non WAAS equipped aircraft are not permitted into high density airspaces (Class B) during peak traffic periods. This gives the user a choice. Do I buy a $1-2K ADS-B transceiver and have some reasonable airspace restrictions, or do I spend $5-10K and have the ability to fly everywhere whenever I want.

Posted by: Mike Schumann | April 29, 2010 12:16 PM    Report this comment

Your right on the money! (pardon the pun). This is the very reason most of us in the avionics industry are worried. THE COST TO OUR CUSTOMER...count on alot of for sale adds in Trad-A-Plane, if this becomes reality. (Then again, maybe that's what the FAA is trying to accomplish?)

Posted by: Joshua Honey | April 29, 2010 12:17 PM    Report this comment

1090ES may be the easiest short term path for deploying ADS-B, but it is 1940s vintage technology that is being held together with bailing wire. UAT is a state of the art architecture that gives us an almost unlimited platform for future ATC innovations.

ADS-B is facing the same kind of dilema that we had with the conversion to digital TV. In the long run, DTV is the way to go. So is UAT. The cost and pain is the transition period where we have to run both legacy transponder technology and ADS-B in parallel. The quicker you do the conversion, the faster you can retire the old stuff, and the cheaper the transition will be for everyone.

Posted by: Mike Schumann | April 29, 2010 12:22 PM    Report this comment

Mike Shumann has it correct. Bandwidth and ability are the limiting factors for 1090ES. The 1090 MHz frequency is already near saturation in many high use areas. The 1090 "Extended Squitter" doubles the message length to 112 bits but even at that, a fully populated ADS-B message, with overhead, needs 5 segments for transmission. So, instead of a single 1090MHz 56 bit message every 6 or 12 seconds, you need five 112 bit messages every second. A great deal of money is being spent to find a solution.

Posted by: Elmer Webster | April 29, 2010 12:30 PM    Report this comment

I agree with the technological aspects but not the implementation. The issue is and always will be outright cost. Not the cost to the FAA and contracted agencies, manufactures, ect…but the owner/operators of General Aviation Aircraft! Never lose sight of what and who we are in the business for….

Posted by: Joshua Honey | April 29, 2010 12:46 PM    Report this comment

One idea for solving the dual frequency issue: build avionics that include one transmitter and two receivers - one for each frequency. This would cost a little more, but not much. It would allow each aircraft to get the transmissions from all other aircraft without ground equipment involvement.

Posted by: PAUL MULWITZ | April 29, 2010 12:54 PM    Report this comment

One idea for solving the dual frequency issue: build avionics that include one transmitter and two receivers - one for each frequency. This would cost a little more, but not much. It would allow each aircraft to get the transmissions from all other aircraft without ground equipment involvement.

Posted by: PAUL MULWITZ | April 29, 2010 12:57 PM    Report this comment

One more little technology comment: WAAS is primarily a small software issue for GPS receivers. That means it is no big deal for new equipment but might mean scrapping older equipment to get the new stuff. Once again, this says that waiting for multiple avionics vendors will save you lots of money.

Posted by: PAUL MULWITZ | April 29, 2010 1:00 PM    Report this comment

Elmer W.

True, but sadly Garmin has a mod ready-to-go for the GTX330 that makes it "out" compliant, albeit for 1090ES. The vast majority of 330GTX owners will want to just do that rather than putting in a new transmitter for 978. That way they'll be "out" compliant as soon as their ground stations come on line.

What that means is that there will be a LOT of GA guys below 18,000 who are broadcasting 1090ES and NOT 978, and that will make it even messier when out of GBT range.

So it seems to me the new rule due out in three weeks should either say:

1) all piston GA below 18,000 MUST transmit 978 "out"


2) Let piston GA below 18,00 transmit EITHER 1090ES or 978 but receive BOTH.

Joshua Honey, as a member of the avionics industry it seems like you guys should get all of you together and make a recommendation and get everyone on the same page (while staying within the FAAA rule guideline) so we have a united front on this, otherwise there may not be any real benefit to ADS-B, or even there may be higher risk of collision, if the current FAA VHS/Beta standard is adopted without a plan

We may have to make this work in spite of the FAA . . .

Posted by: David Rosing | April 29, 2010 1:04 PM    Report this comment

The FAA are looking at multi-lateration, using ground stations to triangulate on Mode S transponders, to provide location information where there is no radar coverage. (mountains)

Posted by: Jim Ward | April 29, 2010 1:04 PM    Report this comment

WAAS is a BIG deal for new equipment. Implementing WAAS may not be a big challenge technically, but it needs to be done in the GPS chip set. Consumer grade chip sets don't include this function, and never will. That means that if you need WAAS support, you have to buy an aviation grade GPS chip set which is at least 10x the cost of a consumer grade equivalent.

If we want to get GA avionics pricing down significantly, we have to use off-the-shelf components that are being produced by the millions for the consumer market.

Posted by: Mike Schumann | April 29, 2010 1:26 PM    Report this comment

WAAS isn't a software only goes from being a "passive" GPS system to an "active" system, that updates continusally.(Thus helping lower the "dither" or time delay) This usually involves at very least an antenna change and a lower lose RF cable. As for trying to get everyone on board, I've already started talking with local pilots. They are all worried about COST. Right now, I recommend they go with a WAAS GPS receiver, and a Transponder with Mode ES capabilities. I figure it will be a shread out between 12,500 lbs, and less, vs. 12,500 more and turbine drivers. The reason is this. The turbine drivers are more likly to flying to Class C and B airspace, the rest of little guys tend to stay around class C and lower. Demand and necessity will drive the FAA twords this. The benifits of WAAS are real and shown today in smaller airports wher ILS's are not feasible. The 1090MHz ES will be much more economical for these smaller owners/pilots as well. The 978 UAT is a great design, for the big guys...I've suggested this to my FSDO,...yup, NO RESPONCE! Nobody want to upset the delicate balance of bureaucratic redrick!

Posted by: Joshua Honey | April 29, 2010 1:31 PM    Report this comment


I'm afraid your information on WAAS is dated. Most (all?) currently available automobile GPS systems, including the $100 variety, claim WAAS compatibility.

As I understand WAAS it is a problem for the GPS satellites to produce the correction information and also requires special ground stations. When it gets transmitted along with the normal GPS signals it only requires the receiver to include the corrections when computing receiver position. Perhaps there is also a message format issue so old units can't be upgraded, but I'm sure new receivers can include WAAS for a very small cost.

Posted by: PAUL MULWITZ | April 29, 2010 1:37 PM    Report this comment

The original UAT design was for GA, not big iron. The concept was to improve situational awareness and provide traffic visibility to ATC in remote areas where radar was not feasible.

Since the CAPSTONE project, the ADS-B program has mophed within the FAA towards a big iron, reduced traffic separation, high density environment, shut down radar type focus. GA has been more or less ignored. The NPRM rulemaking is totally focused on Class A and B airspace, etc.....

WAAS is meaningless for VFR pilots. 95% of GA pilots are not flying IFR. If you want to fly IFR, then you need to pay the price. If you are flying VFR with an $800 GPS unit, you should to be able to buy an ADS-B transceiver to go with it, at the same price point, so you can get weather and see all of the other traffic that is around you. The only thing stopping this, is the lack of certification standards for the low cost MITRE ADS-B UAT technology.

Posted by: Mike Schumann | April 29, 2010 1:50 PM    Report this comment

I'm not a guru on WAAS or GPS. It is possible that consumer grade GPS chip sets include WAAS. The problem is that consumer grade chips don't output the necessary integrity information that is required by the ADS-B NPRM.

The key issue is not WAAS, etc., but the practical question of whether the FAA will allow the deployment of ADS-B transceivers for VFR use that are built using cheap off-the-shelf consumer grade components.

What is needed is the same type of regulatory environment for VFR avionics that has been created for the LSA aircraft market.

Posted by: Mike Schumann | April 29, 2010 1:56 PM    Report this comment

Mike is correct! However IFR pilots and VFR pilots share the same issue ..COST. The "line in the sand" should be 12,500 lbs, and less. Alot of general aviation is comprised of small GA. And many business rely on that! Keep the cost down, and keep the feasibility in reach of the GA. I haven't even metioned the actually installation issue that are present with UAT's , ect...Find me a place to stick a GDL-90 in a Cessna 172..and an MFD...forget it! Not without a huge upfront installtion cost...

Posted by: Joshua Honey | April 29, 2010 1:59 PM    Report this comment

For what it worth, the GDL-90 can display traffic on the 430, 530, 396, 496 & 696. The next generation of UAT equipment is out there, waiting on the final rule. I'm just afraid of what the final rule might look like....

Posted by: Elmer Webster | April 29, 2010 2:11 PM    Report this comment

Good blog Mr. Sanchez!
Interesting how only a few have responded to the FAA's agenda on the NexGen issue using ADS-B, and UAT. There has a been a campaign to keep the UAT 978 MHz portion of this highly capable technology out of the mix but has always been key to the Alaska Capstone Safety Project's development and use in Alaska.
The cost of the equipment has been a challenge that the State of Alaska confronted by offering a revolving loan fund for those who (credit) qualify for both VFR and IFR certified aircraft. This loan has seen little traction here in Alaska which may jeopardize getting more GBT (ground based transceivers) in the future, as per a MOA signed by aviation industry here in Alaska.

Posted by: Rob Stapleton, Jr. | April 29, 2010 2:11 PM    Report this comment

I not read one comment so far that doesn't mention the cost factor. Everyone seems to be an expert on what the FAA should and should not do with regard to ADS-B. As I've said before it's the best thing to come down the pike and I surely hope all the sour apples out there don't get their way. It works perfectly and I would never want to fly without it again. For once the FAA has got it right. Been flying up and down the East Coast for 5 years with it working fine.

Posted by: Joseph Blakaitis | April 29, 2010 2:19 PM    Report this comment

I'm happy to hear your systems works great! How much did you pay for it?

Posted by: Joshua Honey | April 29, 2010 2:30 PM    Report this comment

Installation costs shouldn't be a show stopper. The MITRE ADS-B UAT transceiver is a portable unit the size of a cigarette pack that sits on your dashboard. A permanently installed version could fit almost anywhere, as it does not need to have any pilot controlled switches, etc.

To install one of these you need a GPS antenna, a small comm antenna, power, and an interface cable to a display device (if you want to take advantage of the ADS-B In functionality). One of the things the FAA could do to encourage deployment is to expand the ability of pilots to self install this type of equipment for VFR use, with a simple checkoff from an I/P that it was done correctly.

Posted by: Mike Schumann | April 29, 2010 2:38 PM    Report this comment

For Joshua's inquiry about cost. I already had an MX20 and you already know the cost of the UAT is around $9000.00. As I've said before we all paid 2 grand for transponders in the 70's and with inflation in makes the 9 grand seem normal, and we complained about transponders too. There are many pilots already flying with MFD's so many will not have to pony up for the unit anyhow. They just want everyone to think they will and besides the costs will come down significantly before 2020 and then everyone will be happy. If you had one of these systems you would be amazed at the presentation and ease of mind it gives you.

Posted by: Joseph Blakaitis | April 29, 2010 2:38 PM    Report this comment

I've seen the system in action...I love it! But I'm afraid of the upfront pricing "scaring" pilots of smaller GA into just giving up. It's all I can do to make pilots see the benifits of 406ELT's and TCAS systems. Let alone GPS WAAS receivers and ADS-B UAT's...I still truly believe that a better path may be 1090MHz ES and WAAS receivers for 12,500 and less, and 978MHz and MFD's for Turbines and 12,500lbs and higher. After the cost / benifit curve catches up with demand and need, then 12,500lbs and less can start looking twords cost of ownership. I never have disputed the technology but the path of implimentation.

Posted by: Joshua Honey | April 29, 2010 2:47 PM    Report this comment

Joseph, say more about *why* you like flying with ADS-B.

Posted by: Jess S | April 29, 2010 2:50 PM    Report this comment


1090ES is still primarily a surveillance system. It meets the FAA's needs. Big Iron has TCAS,WX Radar, Flight Directors and all the Comm in the world, and they fly well above terrain. The UAT is a GA pilot's system. I need the all the air-to-air, FIS/TIS and terrain warning I can get, especially when the weather goes to crap. I could not believe how many bogeys I never saw before UAT.

Posted by: Elmer Webster | April 29, 2010 3:12 PM    Report this comment

Joseph, using inflation to justify paying $9,000 for an ADS-B unit is flawed. I just checked Aircraft Spruce and see several transponders for less than $2,000.

I have seen plenty of aircraft panels that have no room for a MFD. What will it cost to remove enough old equipment to install that MFD in addition to the cost of the MFD? Without the MFD or equivalent display functionality, you get nada from ADS-B

Since the FAA is going to save so much money, let them pay for the equipment installation in my plane. They benefit and expect me to pay the cost. That is wrong.

Ron Lee

Posted by: Ronald Lee | April 29, 2010 3:13 PM    Report this comment

Elmer...good strong vailid point.

And you maybe of a handful that is willing to pay for it. Again. I fully understand the's the cost vs. benifits right now..GA is on it's lips, trying to survive.
If we need to impliment something, (in this case a safty of flight item), then make it feasable. Make it small. And make it direct. Someone here mentioned the "406ELT issue" . This is a great case of implimentation without mandate or direction. We all see the absolute benifit to it, but the cost and the direction is not there. And so, this breeds apprehension. Same issue we have here. "What's the cost, who says and why?"
My job depends on the aviation industry and directly to avionics. I keep my ear close to the ground on these issues. And am very sensitve to both the regulations by the FAA and the concearns of the GA community. I'm not sitting by and playing Monday moring quaterback here! I want my pilots safe, happy ,and have a clear understanding of their systems. I also want them to be able to afford to fly. I'm just looking towards an idea to allow them to continue to do so , without breaking their wallets.
The days of LORAN are over, the days of GPS WAAS are just starting, and newer and better technologies are on the way...but go take a look into most GA aircraft today, the radio stack's are often older than my dad. And I have to be able to help both threads of technologies....And now, so does today's pilots...Just make sure they can afford it!

Posted by: Joshua Honey | April 29, 2010 3:42 PM    Report this comment

There may be cheap x-pndrs available now but they weren't then. I have flown over 30 different aircraft and I am sure if I wanted to I could find a place to put an MFD. This is just a way to justify complaining about the system. Again, there will be improvements to come along and the new Aspen Avionics which replace existing instruments in the panel will probably feature ADS-B display soon.

Why should the FAA pay for your installation? They just make the rules and we have to suck them up, like it or not. You are assuming you won't benefit, but you will. You're just not listening because you don't like the cost. You will only have two choices once this becomes law - Quit flying or fly only in uncontrolled airspace---If there is any left by then. Always amazes me that we will pay a fortune for an airplane, not complain when an engine costs us $30,000.00, but bitch and moan about a $5.00 landing fee or something like ADS-B which will revolutionize our flying --- if the FAA gets it right, and I hope they do in this case.

Posted by: Joseph Blakaitis | April 29, 2010 3:50 PM    Report this comment

One note of caution to those of you who are enamored with 1090ES. Has anyone seen a 1090ES transceiver provide ADS-B In services? They don't exist yet. If you want to see traffic, you need to buy an ADS-B UAT transceiver.

I wouldn't get too hung up about the ground station issue. Within the next couple of years, every major airport will have excellent ground station coverage. My gut instinct is that ADS-B ground station coverage will exceed Mode C Radar coverage everywhere.

If you are in the pattern at a small airport in the middle of nowhere, you may not have ground station coverage. However, you will be able to see other ADS-B equipped aircraft using the same flavor of ADS-B you are. The official FAA line is that if you are a GA aircraft you should be using UAT. If we all conform to that, we should be OK, as it is highly unlikely that any big iron using 1090ES will be operating outside of ground station range. If we start having everyone buying a mishmash of equipment, and a significant number of GA users start buying 1090ES transceivers, we are going to end up with a mess.

Posted by: Mike Schumann | April 29, 2010 3:52 PM    Report this comment


1090ES "in" is provided by the Garmin GTS800. You need to modify your GTX330 to be "out" capable, but the GTS800 will receive ADS-B as well as being the active traffic.

Posted by: David Rosing | April 29, 2010 4:04 PM    Report this comment

(ignore if re-post)


Garmin GTS8xx provides 1090ES "In"

You have to modify your GTX330 to provide 1090ES "Out" in order for the UBT to transmit the data to your GTS8xx

Posted by: David Rosing | April 29, 2010 4:09 PM    Report this comment

So what do we purpose to do here fellers? Avionics and Pilots? Help me prepare our pilots, my friends in GA. Help me and the rest of GA get a clear, concise idea of how to fund and intergrate this useful and long over due system. Before it turns into another 406ELT debacle!

Posted by: Joshua Honey | April 29, 2010 4:10 PM    Report this comment

Someone just tell me how to help my fellow pilots/clients impliment this..Cost and regulatory...? Someone please help me find the road map, so we can all get to the next step..

Posted by: Joshua Honey | April 29, 2010 4:12 PM    Report this comment


Who says we're not complaining about $30k engines? Just had the engine blow up in my Comanche and had to do some tough justification to put a $30k engine in a $60k airframe. The last thing I need are another $20k in required avionics upgrades.

You're right that it's a choice between upgrade or quit flying. Why do you think the pilot numbers are dropping?

Posted by: Guy Hutchison | April 29, 2010 4:22 PM    Report this comment

$20k is buying a whole lot more than ADS-B. If you don't need all of that then wait for cheaper configuration to be made. You'll have until 2020 to wait for one. If low-altitude GA doesn't go down the UAT path, Mode S ES won't provide enough value to justify the cost and there will be performance problems.

Posted by: Douglas Helton | April 29, 2010 4:54 PM    Report this comment

Bingo! Douglas nailed it. You scare GA enough, the number dwindle, the demand stays low, the prices stay up...and then what's the point?

Posted by: Joshua Honey | April 29, 2010 5:26 PM    Report this comment

How am I scaring anyone?

Posted by: Douglas Helton | April 29, 2010 5:45 PM    Report this comment

HUh?? How am I scaring anyone into selling their airplane?

Posted by: Douglas Helton | April 29, 2010 5:46 PM    Report this comment

Two quick comments:
1. Mike Schuman: The FAA already has provisions for VFR aircraft to do the same non-certification as LSA. It is called Experimental - Amateur Built aircraft. S-LSA works almost the same way - no STC or TSO required. I believe around 25% of the whole GA fleet today is either experimental or LSA. If you want to fly this kind of GA you can fly this kind of aircraft. If you want to go the certified aircraft route then you need certified avionics. That means always waiting 5 or 10 years after a new technology is available to the experimental community to get FAA certification and also a price reflecting the manufacturer's cost to obtain this bureaucratic approval.

2. The path for most of us to take (in my opinion) is to wait a while before trying to put ADS-B in our planes. I expect good low cost equipment to flood the market in the next few years. When the price is right for you, buy it.

Posted by: PAUL MULWITZ | April 29, 2010 6:05 PM    Report this comment

Thanks to all. This has been an excellent, and largely well informed, discussion of this topic. I personally know that Doug Helton supports GA as much as anyone in the industry. I also know that UAT will prices will soon decrease. New equipment is on the horizon. A major electronics manufacturer in China will soon release their new UAT radio into the market place. They are working on the certification pieces now. That will should help the competition aspect.

Posted by: Elmer Webster | April 29, 2010 6:16 PM    Report this comment

Unfortunately, you can't put a non-certified ADS-B transceiver in ANY aircraft. It's a different animal than a portable GPS display, as it transmits. As a result the device needs to be FCC certified. You can't get FCC certification without the FAA's blessing, and they won't give that to you unless you meet the WAAS and other ADS-B specs.

Posted by: Mike Schumann | April 29, 2010 6:23 PM    Report this comment

As always much of Pauls hatred of ADS B is ENORMOUSLY uncalled for. I can get a Non-TSO's ADS B receiver for $1495.00 ! WHO THE F**K CARES IF IT'S TSO'D OR NOT ?????? It is providing me with WX info WITHOUT A FRIGGING MONTHLY FEE !!! To me that's huge. Paul's chicken little "the sky is falling" routine is getting REALLY OLD ! This mis-guided whining about price would be like someone complaining about the cost of digital watches back in 1976 when they were $400.00 ! Remember how much the Sony Pyxis cost (the first widely available consumer GPS) back in the early nineties ? ANY technology worth having always ends up costing less in just a few short years. The same will be true of ADS-B equipment. Or we can all continue to make XM rich forever.....which would you rather do ????

Posted by: RANDOLPH PALMA | April 29, 2010 9:32 PM    Report this comment

The Navworx transceiver products are "Waiting for FCC approval" according to their web site. They are only currently shipping their receiver products. People need to be careful about investing in ADS-B UAT in only receivers, as the ITT ADS-B ground stations that are being deployed nationwide only transmit traffic data in response to an ADS-B interrogation. If there are no ADS-B UAT equipped aircraft in the area, you won't get any data from the ground station.

Posted by: Mike Schumann | April 29, 2010 9:54 PM    Report this comment

Mike is right, ITT grnd station software was designed to only uplink traffic and wx info when an ads-b target is in view. This was done to preserve 1090 spectrum, but was applied to uat for grnd station simplicity. However it has the effect of requiring ads-b out in order to get tis-b and fis-b (wx).

Posted by: Douglas Helton | April 30, 2010 12:28 AM    Report this comment

Doug:I wasn't implying any "one" person is scaring GA pilots, but that the constant confusion in of itself is!

Mike: You are correct on the technicals of both the ADS-B system and the Certification Requirements of the transcievers.

ALL: The issue is the upfront cost. Period! Otherwise there would be no debate here. The system ADS-B system works, and like all new technologies, it will get better over time, that's how avionics evolve. But our "friends" at the FAA need to give the little guy a reason (financially) to play!

Posted by: Joshua Honey | April 30, 2010 7:42 AM    Report this comment

The best reason to play is the safety factor. Think about this...every midair since UAT ADS-B was certified for use across the National Airspace System in 2001, would not have accurred, if everyone had equipped. That's a lot of dead people. For evidence, I offer that western Alaska had the highest midair rate in the NAS until UAT was certified and installed during the Capstone program. They have had none since. I haven't a clue how many CFITs have been avoided by the MFDs. Some of the Commercial guys have already convinced the insurance carriers that they should get a better rate after equippage. Anybody know someone to ask?

Posted by: Elmer Webster | April 30, 2010 10:07 AM    Report this comment

I need to correct my previous statement...the UAT ground stations always broadcast wx info, it's only the traffic info it withholds until it sees an ADS-B target in view. It also broadcast an indication of TIS-B availability so aircraft equipped to receive that service know that when their traffic display is blank, that it's because no transponder or dissimilar ADS-B equipped aircraft are in the service area.

Posted by: Douglas Helton | April 30, 2010 10:37 AM    Report this comment

I'm not certain the Unsure how FAA's statement that the PHL area has broadcast svc would lead me to believe I could use them without an addition to my cockpit equip. In same way as TIS requires a TIS-capable Mode S xpdr & display, or shooting GPS approach requires a IFR GPS receiver, etc., FIS-B and TIS-B require appropriate equipage.

Major issues with your cost comparison…you seem to have forgotten the cost of the weather receiver and display…an error of about $17K. Here's a more accurate comparison for traffic and wx in the cockpit on a fixed display for a 24 month period:

Cost for 1090/XM wx and traffic: $27K
GDL-69 XM Receiver: $4.5K
GTS-800 TAS receiver: $14K
GNS-400 Navigation Receiver ~$8K
XM Wx Fee: $720

Cost for ADS-B FIS-B/TIS-B/ADS-B wx/traffic: $17K
GDL-90 ADS-B Transceiver: $8K
GMX-200 MFD: $9K
XM Wx Fee: Not Applicable

If we want to look at the cost over a 27.8 year period as mentioned, it's a little uglier: In 2037 you guys compare notes and find that your bill remains $17K for the GDL-90/GMX-200, but your buddy (who is likely not seeing anyone on his traffic receiver after transition to ADS-B based CAS systems) has spent his initial $26K, as well as another $9K in subscription fees, for a total of over $35K. Adding insult to injury, your buddy had to spend another $5K or so by 2020 to meet the ADS-B out mandate for transponder-required airspace…the mandate you met in 2010 with your GDL-90.

Posted by: Todd Stock | April 30, 2010 11:01 AM    Report this comment

I agree that the initial cost is a big factor, regardless of the safety benefits. I worked at UPS AT when the GDL-90 was designed and certified. I know what went into it and why. So believe when I say, it is possible to build a much lower cost certified UAT transceiver and with the volumes that an ADS-B mandate will drive, UAT transceiver should eventually get down close to what a basic Mode S transponder costs today. The only reason it will cost more than a transponder stems from the requirements for the GPS chip and the processor to handle incoming and outgoing data. The power amplifier should be cheaper than that needed for a transponder, so that should help offset those costs. Pricing will be dictated by design innovation and competition.

One of the biggest cost drivers is the proposed requirement for top and bottom mounted antennas. Hopefully the FAA will take the negative comments to heart and go to a single antenna requirement.

The 2020 rule is scheduled to be out this year, and the ground infrastructure in place in the 2013 time frame. This is when the demand will begin and we will start to see new, cheaper designs. I wouldn’t expect to see a lot of ADS-B out only demand until the FAA either expands ADS-B surveillance coverage to non-radar areas and/or allows ADS-B to serve as a substitute for transponders.

Posted by: Douglas Helton | April 30, 2010 11:04 AM    Report this comment

Another topic examined for Capstone was using portable displays for VFR aircraft. With a fixed ADS-B data link (e.g., GDL-90), traffic and weather data can be passed to a portable device...Garmin already uses an line out from the GTX-330 to drive their portable MFDs for traffic via TIS, and Capstone cost estimates assumed these lower cost fixed/portable solutions would address both the panel space issues and display cost. With development of the cigarette-pack sized UAT Beacon Radio, the issues of power consumption and space on small platforms may be addressed - these units have flown in model aircraft and other space/weight/power-contrained air vehicles.

UAT ADS-B is at the high end of the cost curve, while 1090ES is pretty much near the bottom...I expect UAT to get a lot cheaper as other suppliers enter the field, while requirements to meet the newly revised 1090ES MOPS (DO-260B) may keep 1090ES systems up above equivalent UAT systems for a while. Finally, while the GTX-330 and other 1090ES capable GA transponders may have a path forward to DO-260B compliance, the GPS source will have to be upgraded to meet rulemaking. The GDL-90 already uses an integrated WAAS receiver, so no issues there. I did not add the cost of that upgrade to the cost estimate, but for some users, it will be in the $10K range for a new navigator and $6K for a strap-down WAAS engine.

TNSTAAFL, indeed.

Posted by: Todd Stock | April 30, 2010 11:26 AM    Report this comment

If we want widespread deployment of ADS-B, the costs need to come down by an order of magnitude. There is no reason that we can't get down to ~$2K total for a display and ADS-B UAT transceiver if we can use the MITRE consumer grade component based technology.

A good example of what can be achieved on a shoestring budget is the deployment of FLARM equipment by the soaring community in Europe. From a hardware perspective, FLARM is essentially equivalent to an ADS-B UAT transceiver running at lower power levels using unlicensed spectrum. A FLARM transceiver cost ~$1K end user price. Many glider pilots interface this to PDAs running open source GPS moving map displays. With ~$500 investment in hardware and software, you have a fully functional moving map display with traffic superimposed on the image.

Another example of what can be done was MITRE's demo at the AOPA Expo a year or so ago, where they used an iPhone as the display device coupled to their low cost transceiver. Using the compass function built into the newest iPhones, you could develop an app that would function as a poor man's TCAS by giving you audio warnings for conflicting traffic, in addition to displaying the traffic on the screen.

Granted, this is all VFR only, but that's the mass market. If we can hit this price point, there will be massive voluntary equipage. The only think holding this up is the lack of certification standards for the MITRE ADS-B transceiver design.

Posted by: Mike Schumann | April 30, 2010 11:45 AM    Report this comment

WRT the dual link issue, All the people involved in this issue wish there was a simple single-link solution that provided the desired benefit/cost for all users...but there isn't. If there were a way to create a UAT-like system on 1090 that allowed for the current radar-based system, it would've been done. The current radar and transponder system is a patchwork quilt of 30+ years of Band-Aid fixes. The 1090 frequency is stressed to the limit in high density areas and has significant problems handling transponders, radar, TCAS, ADS-B and TIS-B. The FAA and air transport ADS-B proponents started out with a 180nm air-to-air range requirement (to satisfy conflict alert requirements for jets head-on a cruise speed). Due to the 1090 congestion problem, they've now compromised back to 25nm...not because this is what's needed, but because that's all we can expect from 1090 in/over congested airspace.

Posted by: Douglas Helton | April 30, 2010 11:50 AM    Report this comment

To those that subscribe to the "this is a beta vs VHS" issue: it's not. I wish it were then we wouldn't have a dual link solution.

It's more akin to choosing to buy a new house with free electric service (wx info) vs an updated 90 year old house with no electricity for the same price. You can invest in adding electricity to the old house and make the monthly payment. You’ll also be limited by the original 90-year old design…small rooms, narrow hallways, low ceilings, stone foundation, etc…and pay to make more upgrades while you live in it. In the end, you’ll end up spending more for less. The air transport community and their suppliers have already invested in the old house and don’t want to loose that investment buying a new house. GA hasn’t made that investment, hence they can justify buying the new house. You choose.

Posted by: Douglas Helton | April 30, 2010 11:55 AM    Report this comment

The justifications presented here all well and good..the negitive issue presented are also well noted. The issue still remains, how do we, as aviation pilots, technicians, and engineers get on the same page and in the same direction, effectivly. We all know for a fact we CAN NOT rely on the FAA alone, to help us in this endevor. Our first goal is and should always be to promote safety in the skies. But we need to make the solution affordable to the owners, without loosing more numbers. GA is slowly pilots, operators, and airports due to fiscal stresses...let's not add to that problem, but rather make it more affordable and fun and SAFE to fly.

Posted by: Joshua Honey | April 30, 2010 12:28 PM    Report this comment

I must applaud the FAA for moving forward with ADS-implemnentation (especially UAT). Please don't underestimate the significance of this action. We've been waiting for this for more than a decade. It was the single biggest thing holding back this technology. This alone will drive up demand and competition, which will drive down prices. So although I often criticize the FAA, I also must commend them when they are taking steps in the right direction.

Other things that would help are pressing the FAA to drop the WAAS requirement, allow single antenna installations, expand service to non-radar airspace and GA airports, allow UAT in high altitude airspace, use ADS-B based multilateration as a back up to GPS position in terminal areas and migrate to ADS-B based TCAS so we can get rid of radars and transponders.

Posted by: Douglas Helton | April 30, 2010 12:54 PM    Report this comment

Oh one other thing...quit requiring STCs for every model type. Make it easy for mfrs to use the aircraft model list (AML) approach.

Posted by: Douglas Helton | April 30, 2010 12:56 PM    Report this comment

Hi Doug,

Two more items for thought. Some have asked about simplfying the systems, the Chinese have been blue-toothing GDL-90 data to tablet computers for 4 years now instead of a panel MFD and using the computers as moving maps for terrain display, and the University of Alaska Technology Center was putting GDL-90 traffic and services on palm computers about 5 years ago as well. That is about as bare bones as you can get. Alternatives are out there. Being allowed to use such devices is still an issue. Number 2, I agree that the FAA is pressing forward as best as they can considering that the FAA has so many masters to satisfy. The airlines, unions and politicians all have bigger sticks than the GA community at the present time and that's a shame because we outnumber them about 100 to 1. It seems that AOPA, and the other alphabet groups, haven't really banded together and put some hard focus on these issues. Do you think that if this type of discussion was carried out with our elected officials it could influence some of the decisions? We all know the biggest push to keep the 1090 stuff comes from the big iron. They have no need of the other services. Somebody needs to drive a stake in the ground and say were going to UAT below FL 18 by 2014, NO CHANGES ALLOWED! That would spark everyone in the same direction.

Posted by: Elmer Webster | April 30, 2010 3:28 PM    Report this comment

Hey Elmer, how you been. I think there are all kinds of options when it comes to displays...especially when it comes to GA. All the ones you mentioned, and I'm sure others, will come along. The only certification issues really come with position integrity for separation purposes and FCC/FAA interference rules for transmitters. Everything else is negotiable from the safety & regulatory standpoint.

It would be helpful to have the GA community stand together with one voice on UAT. AOPA has really been the only leader in that regard and is the reason UAT is even an option. It's had support from the technical community as well for good reason.

There are number of problems in getting elected officials to pay any attention. Even if they didn't have a lot of other big issues consuming their time, this issue is so technical that it ends up being simplified down to the beta vs VHS argument...and 1090ES wins that argument simply because the airlines and intl community have bought into that archaic approach. Frankly, I'm just happy with FAA nationwide deployment of UAT. The industry and users will take care of the rest.

Posted by: Douglas Helton | April 30, 2010 3:47 PM    Report this comment

Politically, there is no way the FAA is going to fund the deployment of ADS-B on the entire GA fleet. The country is broke. Even if we got the cost down to $1K / aircraft, you are still looking at ~$200M. With the government in charge it would probably be $10K / aircraft, so the bill would be ~$2Billion.

Just wait till you have every TV station in the country talking about handouts to rich pilots so they can fly their jets..... That's not the kind of publicity we need.

We need to focus on getting the green light to deploy low cost equipment that we can all pay for out of our own pockets. The technology exists. We just need to change the worst case engineering mentality that requires every aircraft (including gliders) to be equipped to the same standards required to do parallel approaches in IMC conditions.

Posted by: Mike Schumann | April 30, 2010 4:08 PM    Report this comment

Mike is right. I was just referring to support of UAT ground stations and uplink services.

There's little hope that the polititcians would fund equip. The only way I could see that happening is if ATC was privatized and they saved a lot of money by subsidizing avionics in exchange for shutting down a bunch of ground infrastructure, e.g. radars, VOR, DME, and maybe ILS.

Posted by: Douglas Helton | April 30, 2010 4:37 PM    Report this comment

Interesting you would mention the TV Stations. When the 2 ASTAR 350's got together in Phoenix in 2007 and all 4 people were killed, one of the stations called me and asked if UAT could have prevented the mid-air. My answer was yes, if both helicopters were equipped with a UAT system, it would have provided both pilots adaquate situational awareness to have prevented the accident. AS350's run about $2M new and last I heard aviation fatalities were calculated at about $2M per. That one accident totaled about $12M. Seems like $20k per bird is a very good buy. It can't be just about the money.

Mr. Sanchez, Very good blog. You have hit an interesting topic that needs people way smarted than me to solve.

Posted by: Elmer Webster | April 30, 2010 5:56 PM    Report this comment

A lot of techno speak here. My head hurts just trying to take it all in.

Bottom line for me and it doesnt appear I'm alone. My homebuilt RV-4 as it sits today ready to fly cost me under $30K to build. And it was (and still is) a financial strain to own/fly it. So when somebody points out that the cost of all this hardware is relatively cheap compared to the 1970s cost of a transponder my response is so what. The kind of money that you consider "cheap" would represent over half the cost of my entire airplane.

So without trying to understand all of the techno gibberish, I do understand the benefit of the technology. But until its available in VFR form on a cost scale like Mike Schumann is advocating, I'll never own it. And thats too bad because I'd like to have it.

Posted by: Mike Wills | April 30, 2010 7:07 PM    Report this comment

A great forum. This is a comment from someone just learning about ADS-B. The limitations outlined by the OP are astounding. I see people disagreeing with him but not about the requirement to be over the horizon of a ground transmitter. Despite this lack of disagreement I hope he is dead wrong. How could a system that does not allow any two aircraft to see each other have progressed this far? That should be the first priority surely? I thought that a basic principle of ADS-B was "Digital-TCAS-with-better-information". If that's correct, has it been lost along the way? I trust that I have this all wrong. Thanks John

Posted by: John Hogan | May 3, 2010 11:04 AM    Report this comment

One key element to making ADS-B work in the US is the need for a robust ground station network. The good news is that ADS-B ground stations are MUCH cheaper than radars. Until the national ground station rollout is completed in 2013, it's going to be hard to tell how good the coverage is. My personal instinct is that in most populated area if you are over 1K AGL you will have ground station coverage (I have no basis in fact to back this up).

The FAA's intent is that only the big iron will use 1090ES and everyone else will be using UAT. If everyone abides by this, I doubt we are going to have a problem. If we start having a lot of GA pilots flying around with 1090ES, at remote airports they may not see UAT planes and vice versa. NOTE: Most 1090ES transceivers on the market today do not support ADS-B In, so if you buy one of these you won't be seeing any traffic whether or not you are within groundstation range.

Posted by: Mike Schumann | May 3, 2010 12:15 PM    Report this comment

A week later and I am still reading posts that seemingly don't understand that the UAT/GDL90 portion of the ADS-B equipage is the traffic awareness key to the NexGen program for safety. And what about satellite coverage AND GBTs? I hear ADS-B Technologies LLC in Anchorage has a NEW satellite link to see ALL ADS-B equipped vehicles from afar.

Posted by: Rob Stapleton, Jr. | May 3, 2010 12:46 PM    Report this comment

Rob Stapleton, what did I misunderstand on using GDL90 UAT 978 MHz for traffic awareness? Especially when out of range of a ground-based transceiver and another aircraft is using 1090ES MHz ADS-out?

Posted by: PAUL SANCHEZ | May 4, 2010 3:08 PM    Report this comment

Paul, you understand it perfectly, my comment was in response to the numerous posts that seemingly do not understand the difference between the 1090ES out only and the GDL90UAT 978 MHz transceiver. My point is also that there is a new development using satellite based reception that will be announced shortly.

Posted by: Rob Stapleton, Jr. | May 4, 2010 3:18 PM    Report this comment

Just to clarify: You won't have to buy a GDL90 or a GMX200. You can actually buy the NavWorx UAT for under $3K and the Xtreme Vision Display for $700. The UAT only requires power and a standard GPS and a UAT antenna to be installed. The Xtreme Vision Display communicates to the UAT via Bluetooth. So really there's light at the end of the ADS-B tunnel. We're really working hard to make it affordable! We've been flying with this system for over a year(here in NC)it is unbelievably accurate and puts a lot of our non-pilot passengers at ease when they see exactly what's going on up to 100nm out!

Posted by: Jeremy Brady | May 6, 2010 1:24 PM    Report this comment

I've flown in the Los Angeles basin with a Mode-S transponder with TIS traffic displayed on a 430 for several years now and don't have the confidence expressed by Elmer Webster that mid-air collisions will no longer occur once everyone has traffic displayed in the cockpit. In-cockpit traffic displays may dramatically reduce mid-airs in a low volume traffic area like Alaska by increasing the vigilance of pilots who are accustomed to being the only one in the air at any given time.

For a high density traffic area like LA, the opposite may be true. The nearly constant aural TIS traffic warnings tend to drag my attention away from the outside visual traffic scan inside the cockpit to the 430 display at a time when my attention would best be focused outside. I find that I have to fight to stay focused outside so that I can see and avoid the nearby traffic when I'm in the vicinity of one of the busy local airports.

Bill H.

Posted by: William Harper | May 31, 2010 3:03 PM    Report this comment

On a slightly more technical topic, it would seem that a much more cost effective way to provide ATC with conflict management information would be to implement a nationwide multilateration system. With a ground station deployment density only slightly greater than the planned ADS-B network it is potentially as accurate as gps position reporting, only requires an active transponder on the aircraft in the system and doesn't increase bandwidth requirements. The ground communication network requirements are modestly increased, but the hardware is cheap and the software seems manageable.

If having local traffic info in the cockpit is deemed to be really important, it is no more difficult or expensive with multilateration than it is with ADS-B.

If ATC had accurate position and velocity data on every aircraft, flight following could work much more effectively with little or no burden imposed on aircraft operating within the system.

Yes, I know, ATC would have to work harder or, better yet, someone would have to provide effective conflict management software to help them sort the wheat from the chaff so that operator burden is not increased.

Bill H.

Posted by: William Harper | May 31, 2010 3:09 PM    Report this comment

Bill H. has a good point. Traffic info in and of itself can be a big distraction. An good conflict management and alerting application is necessary to make it an effective mid-air collision avoidance tool.

Posted by: Douglas Helton | June 1, 2010 6:02 AM    Report this comment

Rob Stapleton, I've got the final ruling on PDF (from the AOPA web site originally). I've read thru it and seen where the 1090ES requirements (using a mode-s transponder harnessed to a panel-mount GPS) are less onerous than the original proposal.

I also notice that 1090ES originally was required for aircraft that can operate >FL240, now in final it is ±FL180 thus increasing the number of aircraft that would have to get both a 1090ES and a 978 MHz UAT in the FAA's grand scheme of things. Again my original suggestion to get a 1090ES mode-s transponder and be done with it.

FAA's idea of requiring ADS-B out in class A, B, C, >10k' but yet still requires a mode-c or mode-s transponder as additional equipment (if I elected to install 978 MHz UAT) in the very same airspace makes my decision for easy to make.

Read my comments on the AOPA forum.

Posted by: PAUL SANCHEZ | June 1, 2010 6:29 AM    Report this comment

Bill H,
I'm afraid your multilateration idea is a good one but a long way from the level of service offered under ADS-B. The difference is ADS-B inherently works without any help from ground stations. Traffic display and avoidance can be done without any help from the government.

Conflict avoidance software would definitely be in order - especially in heavy traffic areas. It would be relatively simple to install this software in aircraft. The ability to detect any properly equipped aircraft in your vicinity without help from the government has real value. Even if much of the country is covered by your proposal there will still be areas where this is not available. Most likely candidates for no coverage include the Gulf of Mexico and the Rocky Mountains.

Perhaps we are confused by the FAA focus on ground stations and the transition period where most aircraft don't have ADS-B equipment on board. Indeed ADS-B provides traffic information without any help from ground stations when all aircraft are equipped.

Posted by: PAUL MULWITZ | June 1, 2010 6:44 AM    Report this comment

Posted by Paul Mulwitz on 1 June 2010
"Indeed ADS-B provides traffic information without any help from ground stations when all aircraft are equipped."

When SIMILAR equipped! Which brings back the whole issue of an aircraft that can operate ±FL180 (thus required to have a mode-s 1090ES for ADS-B out) landing at an airport with the other aircraft having only 978 MHz UAT. Both will be a specter to the other unless one has an active traffic system for the other's still installed mode-c or mode-s transponder.

Posted by: PAUL SANCHEZ | June 1, 2010 6:51 AM    Report this comment

UAT and 1090ES equipped aircraft will be able to see each other when they are within range on an ADS-B ground station. I suspect that within a few years there will be very few airports in the country that have turbine aircraft traffic which will not be within range on an ADS-B ground station.

Posted by: Mike Schumann | June 1, 2010 7:03 AM    Report this comment

Posted by Mike Schumann on 1 June 2010

Sounds good, except the comment posted by Paul Mulwitz was that ADS-B provides traffic information without any help from ground stations when all aircraft are equipped.

And as a side note, I happen to notice that the new FAR part 91 rule (effective 1 January 2010) requires 1090ES for any aircraft capable of FL180 or higher, not just turbine. Thus vastly increasing the number of aircraft that will have to have a mode-s 1090ES transponder.

Regarding "not be within range of an ADS-B ground station" I notice that average separation between ITT owned/maintained ADS-B ground stations will be 175 nm (800 transceivers planned), that would be 87.5 nm at maximum distance at average separation. Reception height required for any traffic data (if one aircraft is 1090ES and the other 978 MHz UAT) would be 5,593' AGL. Not exactly traffic pattern altitude.

Oh and if two dissimilar ADS-B aircraft wanted to see each other in the 1000' AGL pattern altitude, I hope the airport is

Posted by: PAUL SANCHEZ | June 1, 2010 7:21 AM    Report this comment

I looked over all the comments here and some were not only excellent, but just darn right superb. Where as others, do have a noteable concern - cost, and lots of it. Plain and simple, if you fly a Normal/Utility Certified aircraft under Part 23, you must install TSO'd equipment. Its the regs, if you want an AIRWORTHY AIRCRAFT signed off by your favorite I.A. If you fly an experimental aircraft or whatever, you can install whatever providing it meets the less than certifiable products. Why do you think everybodys going LSA - you don't need an A&P/IA. VFR pilot/owners most likely will install the simplest, most economical ADS-B Out system in order to fly within Mode-C and will have to meet the TSO requirements regardless of whether the aircarft is certified, experimental, LSA, or just a pair of strap on wings! I'll wait till the last minute and get a used Out transmitter from E-bay for a couple of hundred bucks - OPTOMISTIC. I might even twiddle a Mode-S Xpndr in my basement to do the same, not really :-)

Posted by: Joeseph Gawlikowski: JoesPiper | June 2, 2010 6:28 PM    Report this comment

Planes that fly in Class A space and land at remote fields do present a problem. One solution would be for them to be equipped with dual frequency ADS-B transmitters. This is such an obvious answer for some aircraft I suspect the avionics manufacturers will design it very soon.

For those "Aviation Elitists" who think LSA and experimental aircraft get used junk from eBay I suggest you do a little field work and see just what is in those planes. For the most part they have far better equipment than the old certified items found in Part 23 aircraft. There is NEW equipment available for non-certified planes whenever the manufacturers can make it. Certified planes get only older equipment for prices that reflect the lengthy certification process.

Today you can get a brand new LSA with all-glass panels and all the trimmings for about the same price as a G-1000 upgrade for an aging part 23 airplane. Similar full functionality panels can be found on Experimental - Amateur built planes. Those E-AB planes tend to cost several times the purchase price of a 30 year old Bonanza.

In the end, we all need to consider how to meet the new NAS equipment requirements in an economical and timely manner. I am certain the experimental/LSA community will do so sooner and for a much lower price tag than the certified community.

Posted by: PAUL MULWITZ | June 2, 2010 7:32 PM    Report this comment

The problem for VFR owners is that if I'm understanding the system to date is that transmitters can be had for around $2200-$2400 that include the extended squitter, but to have ADS-B capability, the transmitter requires an IFR certified GPS unit. Please correct me! Why would any VFR pilot/owner install an IFR certified GPS MFD if they don't need or use one, let alone afford it?
That's the quandry I believe?

Posted by: Joeseph Gawlikowski: JoesPiper | June 2, 2010 11:25 PM    Report this comment

Good morning Joeseph Gawlikowski, one reason that I don't mind a C146a WAAS GPS to harness with a 1090ES transponder is because I get more benefit out of the panel-mount GPS than I ever would with a 978 MHz UAT by itself. I have yet to figure out creating a flight plan on a 978 MHz UAT nor how to do an LPV or LNAV/VNAV approach.

Posted by: PAUL SANCHEZ | June 3, 2010 10:34 AM    Report this comment


In theory you're correct, insofar as in-cockpit traffic warning is concerned, for suitably equipped aircraft, ADS-B is independent of ground facilities. For today's fleet of general aviation VFR aircraft the availability of ADS-B based in-cockpit traffic warning comes at great cost and the cost is only slightly lower today's fleet of general aviation IFR aircraft. It isn't clear yet that the system the FAA is implementing has the capacity to handle high traffic density areas like the Los Angeles basin or the area around New York City.

The original idea back in the seventies was to devise a system that would dramatically improve the accuracy of aircraft position determination relative to that achievable using radar. Radar range accuracy is adequate, but the position estimation error associated with angle becomes less accurate the further one is from the radar making the measurement.

Transmitting aircraft position and velocity determined by GPS ala ADS-B dramatically improves position accuracy, but multilateration also achieves that goal. The vast majority of the general aviation fleet already has all of the equipment needed to make multilateration successful, providing all the information the FAA needs to permit closer spacing of commercial airline traffic. It only requires a slight increase in the density of a network of inexpensive ground terminals over that already planned for nationwide ADS-B implementation.

Bill H.

Posted by: William Harper | June 3, 2010 12:08 PM    Report this comment


In theory you're correct, insofar as in-cockpit traffic warning is concerned, for suitably equipped aircraft, ADS-B is independent of ground facilities. For today's fleet of general aviation VFR aircraft the availability of ADS-B based in-cockpit traffic warning comes at great cost and the cost is only slightly lower today's fleet of general aviation IFR aircraft. It isn't clear yet that the system the FAA is implementing has the capacity to handle high traffic density areas like the Los Angeles basin or the area around New York City.

The original idea back in the seventies was to devise a system that would dramatically improve the accuracy of aircraft position determination relative to that achievable using radar. Radar range accuracy is adequate, but the position estimation error associated with angle becomes less accurate the further one is from the radar making the measurement.

Transmitting aircraft position and velocity determined by GPS ala ADS-B dramatically improves position accuracy, but multilateration also achieves that goal. The vast majority of the general aviation fleet already has all of the equipment needed to make multilateration successful, providing all the information the FAA needs to permit closer spacing of commercial airline traffic. It only requires a slight increase in the density of a network of inexpensive ground terminals over that already planned for nationwide ADS-B implementation.

Bill H.

Posted by: William Harper | June 3, 2010 12:08 PM    Report this comment

Sorry guys, I'm not sure how that got posted twice.

Bill H.

Posted by: William Harper | June 3, 2010 12:11 PM    Report this comment

Uhh? I don't understand this comment from Gawlikowski..."I don't mind a C146a WAAS GPS to harness with a 1090ES transponder is because I get more benefit out of the panel-mount GPS than I ever would with a 978 MHz UAT by itself. I have yet to figure out creating a flight plan on a 978 MHz UAT nor how to do an LPV or LNAV/VNAV approach." Currnet mode transponders don't meet ADS-B required TSO standards. 1090ES and UAT require the same quality GPS info.

Posted by: Douglas Helton | June 3, 2010 12:25 PM    Report this comment

Douglas let's try it this way. If I upgrade the gns430 or gns530 to c146a versions so I can harness the output to a gtx330es, can I then use the benefits of LPV
& LNAV/VNAV approaches plus roll-steering output during procedure turns?

If I instead install a 978 MHz UAT what is my benefit procedure wise? Any lower minima? Better flight planning? Less alternate requirements? But yet the 978 MHz UAT must have some sort of benefit other tha to the FAA? Doesn't it have a WAAS receiver as well?

Oh and I almost forgot, I was the one who wrote the comment you did not understand.

Posted by: PAUL SANCHEZ | June 3, 2010 2:11 PM    Report this comment

Fellas, your still talking BIG BUCKS. The issue is Mode-C. As far as position, if you want to see anothers position including multiples, ZAON PCAS is the answer for those that do not wnat to spend any money. The idea is to see and avoid, who cares if the other is seeing you! I use one of the earlier ones(PCAS w/Commant antennae) and it is the answer. I could care less if the tower knows my exact GPS position. In fact, to date the current ADS-B system produces a 12 second delay. Is everybody kidding themselves. Get Real!

Posted by: Joeseph Gawlikowski: JoesPiper | June 3, 2010 6:38 PM    Report this comment

The final rule is published and the dual link decision was retained. Now we can get down to what each system does, or does not do, for us. The new generation of UAT radios have options. Some will continue to have on-board GPS, others will not. Each will have a roll. Aircraft equipped with a certified WAAS navigator will soon be able to buy a relatively inexpensive UAT to hook to it. UAT was never intended to give you navigation or approach capability. It is a certified surveillance tool that can also provide vastly improved situational awareness if bundled with other equipment.

Many very smart people are trying to solve the 1090 frequency saturation issues. I may be wrong, but I just don't believe it can be done. At best, each 1090ES system turned on, consumes the spectrum of more than 55 new mode C transponders. More equipment means less range due to saturation, and when range gets less than 65 miles or so Air Traffic can't do much with it. The Volpe study completed a few years back said effective 1090 range is projected to be less that 20 miles in the high traffic, northeast corridor of the U.S. at current growth rates and I think it was before 2015. Eventually, I believe transponders will go away and transceivers will become the norm. No doubt, getting there will be a challenge

Posted by: Elmer Webster | June 3, 2010 7:02 PM    Report this comment

Adding to Elmers comment: That's why Mode-C is such a huge issue. All VFR pilots do not mind flying around B or C airspace, and who cares about going over 10Kmsl even at altitude (Den) but to fly around Mode-C is like Ok, wheres the hidden fueling stations. More landings, more distractions, just more of the plain ole crap that none of the VFR pilots need. Excellent memo Elmer because it's TRUE.

Posted by: Joeseph Gawlikowski: JoesPiper | June 3, 2010 7:18 PM    Report this comment

Joe, I'm all for anything that keeps airplanes apart. If you'll never need services or operate in controlled airspace, your ZAON might be the way to go but what do you do when there is no radar to interrogate the Mode C's? Also, I'm not sure where you are getting your information, but any ADS-B position data information older than 2 seconds for the GPS timestamp is rejected by the automation systems. Enroute radar normally pings around once each 12 seconds, and terminal updates at slightly less than 6 second intervals. ADS-B continues at a once per second rate.

Posted by: Elmer Webster | June 3, 2010 7:23 PM    Report this comment

I'm amazed this blog is still active! Obviously, it has caught a great deal of attention and sparked some really good discussions. Thanks again Paul.

Posted by: Elmer Webster | June 3, 2010 7:31 PM    Report this comment

Within Mode-C, the ZAON's work off of mode-c or mode-s transponders. I agree though, out in Class-E or Class-G airspace where x-pondrs are not required, the PCAS is useless. Anyhoo, who cares, I fly "eyes out the window" when in VFR! When the clouds are low, I'm in my boat fishing. There ya go, its just age!!

Posted by: Joeseph Gawlikowski: JoesPiper | June 3, 2010 7:31 PM    Report this comment

I've been flying for 36 years. My company's plane is a Navajo Chieftain with all the latest gizmos. It has UAT ADS-B, 1090ES, MFD's multiple WAAS GPS' etc., and receives full FIS/TIS. Once I saw how little of the traffic my naturally installed, mark-one eyeball was seeing, (maybe 1 out of 10) I was shocked! My personal aircraft is a homebuilt and only has Mode C and I'm always on pins and needles until I'm at least 50 miles out of town. I can't wait until a viable solution is affordable enough to put in my flivver!

Posted by: Elmer Webster | June 3, 2010 7:59 PM    Report this comment

You guys are kidding! I fly with complete confidence without flight following within mode-c in Denver as all or at least most are always communicating. I don't know about you, but I do stay off the I-pods, fiddling with knee charts, trying to find what frequency I need (we call this preflighting and preplanning) and fly eyes out the window (VFR). Common, you all do know how to slip and skid if necessary. IFR, you bet-whole and complete different story. Thats why ADS-B in Mode-c is the issue. Its not necessary for VFR pilots at low altitudes or a specified AGL altitude (maybe 1500-2500agl) know they can fly around Bravo and Charlie. But to have to fly around Mode-C, fellas, the FAA is stretching it, plain and simple. Its the cost, until a unit thats cheap, not economical, not thrifty, but cheap to comply with ADS-B Out for certified aircraft. This debate will continue until common sense is realized. BTW: I won't get into what aircraft I have flown, but I will always stand up and fight for common sense and waht is practical for safety. I wish I owned a Chieftan with a space shuttle instrumentation panel! :-)

Posted by: Joeseph Gawlikowski: JoesPiper | June 3, 2010 9:34 PM    Report this comment

You sure sound alot like me a few years ago. Until I actually started flying with the gear I had no idea what I was missing. Mid-airs very rarely occur between 2 IFR aircraft. They nearly always involve at least 1 VFR guy, more often that not, 2 VFR guys, doing their best to fly safe. I have no fear of any aircraft I can see. The closest I've come to a mid-air (that I know of) happen during a BFR about 8 years back. Downwind leg, mid-field, controlled airport, guy in a 180/185 crossing the airport AT PATTERN ALTITUDE just instantly appeared in the windscreen. I pushed over hard, CFI saw the other guy at that instant too. We cleared by a few feet but I swear I could read the tire size! Soon as I recovered, the CFI was on the radio to tower, but they hadn't seen him either. I still can't believe I hadn't seen him way earlier. Then along came this gadget. I might see 2 or 3 planes out the windows at one time, while flying across town, the gadget showed me 2 dozen or more within 5 or 6 miles. Fortunately, it's a big sky! Odds of hitting something are small, the gadgets still give me better odds. When the FAA did the Capstone program in Bethel, they had the worst accident rate in the nation. The safety reports said someting like you were 17 times more likely to die out there, in a mid-air, than anywhere else in the NAS. Since Capstone was installed, they haven't had in mid-air in more than 10 years. Now I'm just waiting till something comes out I can afford.

Posted by: Elmer Webster | June 4, 2010 11:28 AM    Report this comment

FYI Joe, I wish I owned the Chieftain too...I'd sell it and buy something fun to fly!

Posted by: Elmer Webster | June 4, 2010 11:28 AM    Report this comment

Let's try to understand the 1090ES frequency congestion issue. It is primarily brought about by adding state vector data to other data already transmitted by Mode-S transponders. If the aircraft state vector data was transmitted INSTEAD of the other data rather than IN ADDITION to it the frequency congestion/bandwidth problem would be solved. The FAA seems to have rejected that idea out of hand. WHY?

Bill H.

Posted by: William Harper | June 4, 2010 11:30 AM    Report this comment

Elmer: I concur & roger that.
It's the mode-c issue thats all. The resrtictions were stretched a bit and even though the costs may be reduced over time, the point being that small aircraft owners just don't go out buy electronic devices just have them in the plane. Small aircraft owners fly to fly, that's the fun of it. The nutshell.

Posted by: Joeseph Gawlikowski: JoesPiper | June 4, 2010 11:47 AM    Report this comment

The problem with 1090ES is the EXTREMELY limited bandwidth that is available and the need to stay compatible with existing transponder / TCAS systems.

The long therm answer for EVERYONE is ADS-B UAT. There is tons of bandwidth, permitting lots of new features to be added in the future. The costs are intrinsically low (MITRE's prototype transceiver has a parts cost of

Posted by: Mike Schumann | June 4, 2010 11:52 AM    Report this comment

I'll send in 10000, thats right 10K letters myself alone. I know of the MITRE box, and thats just a start for an economical unit. All they want is a broadcast of GPS position and N#.

Posted by: Joeseph Gawlikowski: JoesPiper | June 4, 2010 12:07 PM    Report this comment

Bill H.
I can't answer that specifically. I can say the ADS-B message payload/format was established and agreed to, by an international committee and approved for use as world-wide standard. (See RTCA Do-260 & EUROCAE ED-102) Also, the 1090 systems has to serve many masters. Obviously, the Mode S boxes support Mode S systems, but they also require compatibility all the other FAA radar automation systems, plus ASDE, MLat, TCAS and who knows what else. I do know that only the UAT system prioritizes the data to insure position information gets through at the expense of all other data if the system loads up. Thats probably in the neighborhood of about 600 aircraft using the same GBT which is unlikely.

Posted by: Elmer Webster | June 4, 2010 12:08 PM    Report this comment

I think we are in violent agreement here.

I too believe the world will end up at UAT. It's the only thing I've seen to date with the capacity and capability to handle everything. The problem is transition. Think of what's at stake. If the heavies equip with UAT, TCAS can go away, MLat, Enroute Radar, etc. The major manufacturers have enormous investments in those technologies and are lobbying heavily to keep them alive (ie 1090ES). Thus the Boeings/Airbus people mistakenly believe it will cost them millions to transition. They don't know China is already using UAT in high flyers. As to the components, any position data in the air will be used by everyone and human life hangs in the balance. I want a certified product too. But it doesn't have to cost $5 or $6k. Aviation has always been held to inflated pricing by the manufactures based on what the market will bear, not cost plus profit, like everything else in the world. They use terms like "Non-Refundable Engineering" "process and certification costs", which are real, but are not as excessive as the pricing indicates. We should be able to buy fully certified equipment for less than $3,500, probably less than $3,000 if the truth be known.

Posted by: Elmer Webster | June 4, 2010 12:35 PM    Report this comment

One way to get the price way down for everyone is for the FAA to hire MITRE to design and certify an ADS-B UAT transceiver that everyone can freely license, using the same business model that FLARM developed in Europe. Then, as ADS-B evolves, everyone can update their firmware, so we don't end up with some legacy units flying around holding back the upgrade of the entire system.

With this kind of business model, it might cost the FAA $5-10M in upfront engineering. The production units should easily be available at a street price of under $1,500, particularly if, as part of the deal, the manufacturers are protected from liability for design problems.

If ADS-B UAT transceivers were available at this price point, there's no reason every airliner couldn't be equipped, and we could then completely eliminate Mode C/S transponders and switch to a 100% ADS-B UAT environment for TCAS as well as ATC RADAR replacement.

Posted by: Mike Schumann | June 4, 2010 12:45 PM    Report this comment

See, within only a few days with a few people brainstorming the answer was born. Now all we have to do is make it happen! Good job Mike Schumann! :-)
Let the product competition begin!
I suggest lobbying that idea format immediately - I will also.

Posted by: Joeseph Gawlikowski: JoesPiper | June 4, 2010 1:22 PM    Report this comment

Mike Schumann, In the interest of full disclosure, what exactly is your relationship with MITRE?

Posted by: RON QUILLIN | June 4, 2010 1:40 PM    Report this comment

I have absolutely no association with MITRE, either professionally or financially. As a quasi-public think tank, doing engineering design for the FAA and DOD, MITRE is not able, legally or politically, to lobby or market on their own behalf. I am just helping spread the word about the technology that they have developed, which would otherwise be hidden in the technical journals and the proceedings of aviation related conferences.

We need everyone to help spread the word that the technology exists TODAY, and that the whole Nextgen problem can easily be solved if the FAA would focus its energy on getting a low cost ADS-B UAT transceiver commercialized ASAP.

Posted by: Mike Schumann | June 4, 2010 1:57 PM    Report this comment

Check out

Posted by: Joeseph Gawlikowski: JoesPiper | June 4, 2010 4:32 PM    Report this comment

It is only a matter of time. An inexpensive IN/OUT system is on the way! With the final rule published I'm certain several new certified products will appear.

Posted by: Elmer Webster | June 4, 2010 5:31 PM    Report this comment

People need to be VERY careful about buying ADS-B IN only receivers like the skyscope product. The ADS-B ground stations that are currently being deployed only transmit TIS-B data in response to an ADS-B interrogation. If there are no planes in the area that are transmitting ADS-B OUT data, you aren't going to receive any traffic data from the ground station.

Posted by: Mike Schumann | June 4, 2010 6:11 PM    Report this comment

Just coming back to the blog...

Paul, sorry I mistakenly associated your comment with Joe's.

So your point is that you already have a Mode S ES transponder and that investing in a WAAS upgrade for your 430 would provide more benefit than investing in a UAT transceiver. I would agree. But you'd have to invest in WAAS regardless. The real issue will come when you have to upgrade or replace your GTX your 330 to comply with rule or invest in a UAT transceiver. The 330 will require at least as software upgrade if not a firmware upgrade.

Even then, the upgrade may be a lower cost than a UAT transceiver...but you won't be getting weather info and TIS-B info may be eventually be scales back to deal with 1090 frequency congestion. So it may not be the better deal even ignoring that you won't be able to see UAT equipped aircraft air-to-air.

Posted by: Douglas Helton | June 4, 2010 7:50 PM    Report this comment

Bill and Elmer, interrogations is the primary reason for 1090 frequency congestion. Without them, congestion wouldn't be an issue. But radar, TCAS, TCAS/PCAS all require interrogations to work...and multiple interrogations at that. Ranging accuracy is great, azimuth not so good...that's why TCAS only works at close range.

If you got rid of the need for interrogations, you'd have to broadcast aircraft and position information. Since it is digital info rather than pulse info, you don't need to send multiple copies of the same thing within microseconds. 1 sec intervals is good enough and you'd only have to send one mesaage with all the info. That's ADS-B. If you could do that on 1090 you'd effectively have UAT without the weather and TIS-B uplinks.

Posted by: Douglas Helton | June 4, 2010 8:02 PM    Report this comment

I whole hearted agree with the notion of getting rid of transponder-based technology in favor of ADS-B...that includes tranponders, cooperative radar (SSR) and transponder TCAS. However, you have to address the GPS vulnerability issue..can't have every airplane in and around a class B area suddenly disappearing from controller and aircraft displays. This is where multilateration should come in. We're going to have mulitlat at all the major metro airports for surface surveillance...may as well leverage it for wide area surveillance backup. Alternatively, with enough UAT ground stations, UAT is capable of calculating it's position...just not as precise as GPS...but good enough for separation services.

Posted by: Douglas Helton | June 4, 2010 8:09 PM    Report this comment

Thers is only one hope if the current rule were stay as it is: 91.225(g)(2). Non- equipped ADS-B aircraft must submit permission 1hr prior to activity. Hopefully you could just add this to your VFR flight plan and you would know at least 15 minutes before the flight - are you kidding?
Of course if the rule were enforced today, VFR certified aircraft wouldn't even be in the ballgame, in fact, they're outta the stadium entirely!
So, the FAA wants only IFR Certified GPS ADS-B aircraft (other than non-elec aircraft, gliders and balloons) to be able to fly within Mode-C.
Seriously, I can't stop laughing because it is that serious of a threat to GA since a considerable amount of GA aircraft within Mode-C are not IFR certified or equipped, and somebody really thinks (pessimism) that all of this mess will be affordable later on? I spoke with a fella today at a fly-in that owns a newer Saratoga thats hard-loaded, and he said it's all nice, but if I stare at all my toys on the panel, I never get to fly the plane and enjoy the scenery. He said, I'll just double the size of N# so its more visible :-)
Almost forgot: IFR only certified aircraft in no way will be enough aircraft to even support the system via government. When Part 121 & 135 operations have to ante-up more dough due to the losses, changes will be made, gauranteed. I know, we have 9 1/2 years - heh, heh, heh :-) It's exactly when I fully retire and I'm part-time now. Good luck to all :-)

Posted by: Joeseph Gawlikowski: JoesPiper | June 5, 2010 3:39 PM    Report this comment

The FAA is compelled to stack commercial traffic closer together since the demand for air transportation is increasing while the number of destination airports and runways remains virtually frozen in perpetuity. Here in California a serious effort was mounted to turn El Toro, the major US Marine Corps air field in Orange County, into a commercial airport when the property was released from the government inventory. That effort was doomed from the beginning by locals who were pleased to do away with airport noise. Everywhere in the country similar efforts to provide additional runways have been killed at conception.

Without new runways to serve commercial air traffic, efforts to increase air transport capacity are only going to be marginally effective so every effort should be made to reduce the impacts to GA. Multilateration achieves the accuracy improvement needed to increase commercial traffic density with no impact on the GA VFR or IFR fleet, introduces no new frequency allocation, or frequency congestion problems and with only an upgrade from Mode C to Mode S, it even provides the FAA with the information required to bill us for our use of the airspace. Why was it not more seriously considered?

Bill H.

Posted by: William Harper | June 7, 2010 11:16 AM    Report this comment


The reason for 1090ES congestion is not interrogations per se, it is the addition of state vector data to the identification data demanded by the Europeans to permit them to establish automatic billing of airspace users. The addition of state vector to the identification data requires additional transmissions to get it all dumped within the bandwidth restrictions of 1090.

In addition to the accuracy issues associated with radar the revisit rate dictated by mechanical scanning is unacceptable for separation control of high speed aircraft. Multilateration solves the accuracy and revisit rate problem. Deleting the id while using US airspace would solve the bandwidth problem eliminating the need for a UAT for folks who don't feel the need for the full spectrum of ADS-B services. GA aircraft planning to fly to Europe would need a dual mode transponder. Those of us who don't intend to fly our VFR GA aircraft to Europe shouldn't be driven by the airlines need to be in lock-step with the Europeans.

Bill H.

Posted by: William Harper | June 9, 2010 12:14 AM    Report this comment


With regard to your June 7th comment, there’s a lot of truth in what you say about needing more runways and airports…or at least the need to leverage under utilized air carrier airports. That requires broader policies that encourage business and population to move to those areas.

Preliminary analysis of the NextGen concept (specifically…the advanced operational applications that make up NextGen), indicates that there is still more capacity in the current system we can leverage before we need those extra runways and airports. However, given the long lead times it takes to add runways and airports, I think we need to start now so we have them available when demand maxes out the capacity of our current airport network. That’s a long way of saying I agree with you.


Thanks for the thoughtful response. It's been a while since I was immersed in the 1090 intracacies

Posted by: Douglas Helton | June 9, 2010 3:04 PM    Report this comment


WRT to your June 4th and 9th comments on 1090 congestion, thanks for the thoughtful reponses. It's been a while since I was immersed in the 1090 technical issues, so I have to do a little homework and get back to you. However, it's my understanding that state vector + ID in response to an interrogation is not a requirement in the U.S. and therefore not contributing to our congestion problem...but I will confirm this.


Posted by: Douglas Helton | June 9, 2010 3:28 PM    Report this comment


When you say, transmit "the aircraft state vector data was transmitted INSTEAD of the other data rather than IN ADDITION to it," what do you mean by "other information?"


Posted by: Douglas Helton | June 10, 2010 9:12 AM    Report this comment


If I recall correctly, the standard mode S data transmission comprises 112 bits in each transmission of which 24 bits are dedicated to the unique aircraft code. That information is useful in the automated service billing systems being developed in Europe, but isn't needed to assure safe aircraft separation so it could be made available for data that is. I'm confident that the mode S data format could be mined for other examples of data that is interesting to some but not essential for safe and efficient aircraft separation services including TCAS.

Posted by: William Harper | June 11, 2010 12:28 AM    Report this comment


the ID info is at the heart of reason for mode s' existence. The ID reduces the number OD radar and tcas interrogations by allowing selective interrogations so that only the aircraft for which you need an update respond. I believe it might also reduce the number of repeated responses to a single interrogation, but I'm not 100% sur eof that one. Removing ID would essentially put us back to an ATCRBS world, require more interrogations and relys and make the congestion worse.

Posted by: Douglas Helton | June 11, 2010 7:22 AM    Report this comment


You only have to provide a unique aircraft ID because of the data that is being demanded by the Europeans who require, among other things, that Mode-S aircraft transmit assigned altitude as one of many pieces of data that can be requested by the interrogating station on an individual rather than collective basis. I suppose that they find it inconvenient to ask pilots to repeat back their assigned altitude so they force them to enter it into the aircraft system and force the system to be capable of transmitting it on request.

To impose a large financial burden on the US VFR user community making an already expensive hobby even more expensive so that the FAA can be compliant with European standards established to ease automatic billing for traffic separation services is not something we should be all that supportive of.

Bill H.

Posted by: William Harper | June 11, 2010 10:28 PM    Report this comment

I am perplexed on why this extensive discussion of 1090ES. For GA, the way to go is ADS-B UAT. This is the newest, best, and cheapest technology. The challenge we face is to get the FAA to relax the UAT standards for VFR users, so we can take advantage of the low cost technology that MITRE has developed.

Eventually, when ADS-B UAT transceivers become available at reasonable cost, and are widely deployed, the FAA might see the advantages of switching to this technology for all aircraft as a way to finally eliminate the need for Mode C/S transponders.

If, on the other hand, GA users start deploying 1090ES transceivers in large numbers, the migration to a pure ADS-B environment will become much more difficult, and we may all be saddled with Mode C/S transponders forever.

Posted by: Mike Schumann | June 11, 2010 10:54 PM    Report this comment

Indeed Mike! The FAA has finalized a rule with no standards other than what the TSO should be sort of. In addition, the finalized rule is similar to certifying an aircraft without compliance to CFR14Part 21&23 and just saying this is an experimental system and we are allowing the private sector to figure it out for us without any set standards at this time. This rule was enacted in haste and should be retracted until further standards are created. As I converse this topic across airfields around Den, I have yet to find a small GA owner that will convert.

Posted by: Joeseph Gawlikowski: JoesPiper | June 12, 2010 9:38 AM    Report this comment

The only European specific requirements are in elemantary & enhanced surveillance standards. That information is only transmitted by aircraft when a specific interrogation requests it. US radars don't have the capability to make that interrogation. So I'm not getting your proposed solution. Bottom line is...attempting to run both the radar/transponder/TCAS systems simultaneously with ADS-B is the root cause of the 1090 congestion problem. More modifications to 1090 equipment will continue to be needed to cope with the problem and end up costing everyone more than had they just left the Mode S/C system alone on 1090 and implemented ADS-B on a different system and frequency. If not UAT, then what? UAT provides the most bang for the buck and avionics will eventually end up the same price or less than a mode C transponder.


Posted by: Douglas Helton | June 12, 2010 11:47 AM    Report this comment


The alternative is to achieve roughly the same position and velocity accuracy achievable with gps based ADS-B by employing Mode-C transponders with a different, ground based, method of position determination called multilateration.

That approach has negligible impact on the VFR fleet since the vast majority, all within the mode-c veils, are already equipped with Mode-C transponders and it provides the accurate position and velocity data needed to permit reduced separation between commercial flights and accurate knowledge of the position and velocity of VFR aircraft.

1090 has more than enough capacity to handle multilateration interrogations and TCAS. 1090 doesn't have the capacity needed when you add the transmissions required for all the data needed for full capability ADS-B implementation, so UAT, operating on a different frequency, provides the additional bandwidth needed for the data while accommodating TCAS on 1090.

Bill H.

Posted by: William Harper | June 13, 2010 4:54 PM    Report this comment

Multilateration is fine. However it doesn't upload traffic data or weather. The big advantage of ADS-B UAT is the ability for pilots to accurately see all of the other aircraft in their area.

We don't need to reinvent the whole FAA nextgen strategy. What we need is inexpensive hardware!!!!

Posted by: Mike Schumann | June 13, 2010 6:06 PM    Report this comment

Amen Mike! I'll check back in a few years from now.

Posted by: Joeseph Gawlikowski: JoesPiper | June 13, 2010 7:33 PM    Report this comment

Bill, multilateral does not do much more than radar. The whole point of ads-b is so aircraft can see eachother with much greater accuracy and info than tcas. This is what allows us to ultimately move beyond basic radar ops. Granted...the FAA should approve these operations before mandating ads-b, but that's not where most ga operators will get there benefits. Seeing other traffic and getting weather & NAS status info is where we get our benefit. Of course...We never counted on having two dissimilar systems and relying on ground stations to translate.


Posted by: Douglas Helton | June 14, 2010 7:15 AM    Report this comment

Doug and Mike,

Its clear I'm talking to true believers in ADS-B, so I should probably just sign-off, but I've tilted at windmills before so here goes.

Multilateration provides all the information the FAA requires to increase commercial traffic density at no cost to the VFR GA community while the ADS-B solution to the same problem has great impact with no benefit to that same community. To get the benefits offered by ADS-B one must spend a lot of money in comparison to the value of the average GA VFR aircraft.

Even if Mike's pleas for commercial solutions are heard in time and positively responded to, the equipment won't be free, installation won't be cheap and useful load will be reduced for those opting to get the benefits and for those who don't feel a need for them.

ADS-B is a lose-lose proposition for all concerned and there is still no guarantee that the system has sufficient capacity to handle high traffic density areas like New York and Los Angeles.

Bill H.

Posted by: William Harper | June 14, 2010 12:22 PM    Report this comment

The FAA has not sold anyone a bill of goods. The FAA took a great idea to increase situational awareness for GA pilots, and completely refocused it on replacing its RADAR infrastructure and supporting high precession parralell approaches for IFR traffic. In the middle of this GA was totally forgotten.

The assertion that ADS-B provides absolutely no benefit to GA is absurd. That may be the case if you invest in ADS-B out only, but the whole intent all along was to receive traffic and weather data.

The key issue we need to focus on is to get the FAA to provide the green light for the Navworx and MITRE low cost ADS-B technology to be deployed. These boxes are affordable and provide dramatic improvements in GA's ability to see and avoid conflicting traffic.

Posted by: Mike Schumann | June 14, 2010 1:00 PM    Report this comment

IIRC, wide area multilat was evaluated as an alternative to ADS-B and found to be more expensive than either single or dual links for national deployment. Limited area multilat in specific area such as Juneau, AK was determined to be relatively cost effective where there is significant non-equipped traffic (airports which do not rate a Class C, but still get significant non-equipped aircraft counts and air carrier traffic), so is an element of the NAS.

As to link capacity? Please try to preface your remarks re: ADS-B channel loading with either 1090 or 978...UAT does not have a channel loading issue under any future scenario I've seen proposed or can think of on my own.

Finally - the mandate is for ADS-B out, and we already have market entry for additional UAT systems which should result in competitive pressures on manufacturers. Folks have been working the cost issues...MITRE's UAT Beacon Radio research - conducted over the last few years - has resulted in development of very small, lightwight, low powered UAT transmitters and tranceivers being developed to explore the low cost/small/lightweight trade space.

Posted by: Todd Stock | June 14, 2010 1:18 PM    Report this comment

Mike Schumann, you keep on talking about how much a 978 MHz UAT should cost as if you were both vice-president of marketing & engineering at MITRE (or NavWorx), which I have a sneaking suspicion you are neither. Making promises for other manufacturers on how much an ADS-B 978 MHz UAT should cost is about as productive as me promising that Garmin should lower the price of their GNS530W down to $2.5k since the product has been out the door for 10 years now. I'm not likely to influence Garmin (or any other manufacturer) very much with that promise and I'd be quite foolish to make that promise (or premise).

Your repeated exhorting of the benefits of 978 MHz UATs (provided everyone gets one) reminds me of Bernie Madoff in reverse, you try to the first 50% of aircraft owners to invest in a $8k 978 MHz UAT so that the next 25% will only have to pay $4k and the next 12.5% after that will only have to pay $2k.

Since the FAA has decided that not only mode-c & mode-s transponders are still required for >10k', class B, C, etc and in fact a brand new 1090ES is required above FL180 I think the decision has pretty much been made what people are going to get.

Posted by: PAUL SANCHEZ | June 14, 2010 2:20 PM    Report this comment

(comments to Mike Schumann part deux)

Your premise that people should get the 978 MHz UAT so "it will be cheaper for others later on" I find quite amusing but I don't think that many owners are going to take your advice.

As I've posted before when manufacturers start selling 978 MHz UATs for $1.3k (about 50% of a mode-s transponder such as the Trig TT31) is when aircraft owners "might" consider buying one and having it installed. Till then there is just way too much benefit of getting XM weather delivered directly to you at all altitudes (rather than an intermediary) and an active traffic system to see the required mode-c/mode-s transponders anyway.

Please let me know when the FAA is installing 978 MHz UATs for free like they did in Alaska. Now that was a great deal cost/benefit wise.

Posted by: PAUL SANCHEZ | June 14, 2010 2:20 PM    Report this comment


The facts are that Garmin has been the only UAT manufacturer in the market. With rulemaking, that will change. Even without the less expensive panel mount and portable options coming down the pike as the avionics industry and new entrants gear up, the traffic and weather services provided by UAT-based ADS-B are less expensive than other alternatives for those not already invested in active traffic systems or commercial satellite subscription-based services. As I mentioned in my correction to your cost statements, whether 1090ES or 978, the ADS-B system will need a WAAS position source, and most cost analyses gloss over that fact, as they do the $2500-$3000 delta in display costs when equiping panel mount MFDs for XM and non-ADS-B traffic and the $600 per year subscription fee for satellite services.

Posted by: Todd Stock | June 14, 2010 4:19 PM    Report this comment

And again Todd Stock, where are these non-Garmin ADS-B UATs and I mean the ones with minor things like FCC approval and FAA TSO? I put in a TSO C146a WAAS receiver presto chango I have the benefits of a C146a receiver for LPV and LNAV/VNAV approaches (plus a plethora of other features on the GNS480, GNS430W or GNS530W).

As I wrote to Mike Schumann, please let me know when the FAA is installing 978 MHz UATs for free, that is the only way a majority of aircraft owners are going to be using it (thus increasing the number of people who have drunk your FAA's recipe for kook-aid).

This issue was settled when the FAA decided that aircraft above FL180 would need a 1090ES broadcast (very similar to the transponder they already have, what a coincidence) and ALL aircraft owners must still have a working mode-c or mode-s transponder for all class B, C, >10k' MSL.

Posted by: PAUL SANCHEZ | June 14, 2010 4:44 PM    Report this comment


I believe I stated that there were systems in the pipeline...most manufacturers take a dim view of releasing a product claiming compliance with a rule before that rule is published. Bad form and all that. I would expect announcements at Oshkosh from several outfits looking to fill the need for the 200,000+ aircraft which will have to equip for the mandate and which will have a full network of ground stations available by 2013.

I believe I made a sincere effort to address the points raised in your original blog, as well as subsequent responses...please be so kind as to do the same.

Posted by: Todd Stock | June 14, 2010 5:00 PM    Report this comment

Todd then let the individual aircraft owners decide. Make your suggestions to your clients and I'll make my suggestions to my clients when they ask about 978 MHz UATs. Send me an email a year from now on how many ADS-B 978 MHz UATs have been installed and at what price. Always happy to be wrong with results (rather than just forecasts).

Posted by: PAUL SANCHEZ | June 14, 2010 5:09 PM    Report this comment

Apparently the paranoia is so extreme for some that bearing the thought of not knowing or being able to fully a see another airplane 5 miles away has them shaking within their crustacian shell. For those that are that paranoid, I suggest flying with MS Simulator within the comforts of your home and leave the GA NAS to those whom can handle the responsiblity as we all have diligently to date. Electronic toys will not save your life 100%! In many cases they will endanger it instead. The only full usefulness of ADS-B is truly within IFR. If you have to scud run that close as a VFR pilot, its time to hang your wings and go fishing.
Pure and simple - BIG BUCKS for NOTHING for GA VFR.

Posted by: Joeseph Gawlikowski: JoesPiper | June 14, 2010 5:12 PM    Report this comment


First and foremost, there's no rush to equip with a 2020 mandate, so let the early adopters spend what they will and allow the market to work. By the time the mandate hits, the folks that don't want traffic or free weather will have a fairly low cost box to satisfy the requirement. For those that want traffic and weather, we'll have a fully built out ground network by 2013, so benefits will acrue to those that equip. Another good reason to wait beside market dynamics is that as we get further into NextGen, we get closer to seeing when the transponder mandate - required so that Big Iron TCAS and all those active GA systems will work - will go away.

Posted by: Todd Stock | June 14, 2010 6:30 PM    Report this comment


In my experience, pilots flying with ADS-B & broadcast services for the first time always remark on how much traffic they are not seeing. Same thing when folks fly active traffic systems in an environment with mandatory transponder equipage. I'm sure you've never missed identifying anything larger than a sparrow within three miles of your aircraft, but sun angle, atmospheric conditions, prop or rotor sheen, and a whole host of other issues can and do reduce traffic situational awareness through no lack of diligence of the crew.

Midair collisions are only one of the uses for airborne traffic...runway occupancy, traffic pattern usage, and weather effects on aircraft operations are all apps that we saw pilots in Alaska 'discover' as they did what pilots do...wring out the system.

Posted by: Todd Stock | June 14, 2010 6:45 PM    Report this comment

Sounds good Todd that you think the FAA will not require mode-c or mode-s transponders for FAR 91 aircraft when in US airspace

Posted by: PAUL SANCHEZ | June 14, 2010 6:49 PM    Report this comment

Given that there are no 1090ES ADS-B In systems available at the present time, and ADS-B Out has little or no value to users other than to satisfy a distant mandate, I suspect that GA equipage between now and roughly 2013 will be UAT ADS-B In or new aircraft deliveed with GTX 33/330 units (1090ES ADS-B Out only). That should be enough time to see where things are going to go WRT the cost of traffic and weather, and the value proposition for low end users.

Posted by: Todd Stock | June 14, 2010 7:29 PM    Report this comment

Does anyone but me remember the great promise held out for Mode-S? The ground component was going to be deployed in moderate to high traffic density areas nationwide to provide in-cockpit traffic for anyone suitably equipped. When I upgraded my panel to include a Garmin 430 I purchased a Mode-S transponder to replace a perfectly good Mode-C in order to get the additional service. The new paint on the panel was barely dry when the FAA announced that they were going to decommission a number of operational Mode-S radar sites to save money and wouldn't install any more.

I still get Mode-S based in-cockpit traffic service in the Los Angeles basin, but the dream of having it in the busier areas I fly through each year on the way to OSH died on the vine.

Anyone taking bets on how long free ADS-B will last? I'll enter the pool if sufficiently near-in dates are offered in the pool.

Bill H.

Posted by: William Harper | June 17, 2010 11:55 PM    Report this comment

UAT traffic in the cockpit for $800 and the cost of an iPad...multiple TSO'd systems, to include dual-frequency units that receive both 1090ES and UAT. At the close of the 2012 FY, my status sheet includes so many entries that a single page shrink-to-fit print job is no longer an option...

Is panel-mount ADS-B still expensive? I would say yes - my cost analyses still show an $8K cost to get to either 1090ES or UAT equipage compliance for aircraft without WAAS or displays that handle auto code setting - and that is without the cost associated with the single-model STCs that the FAA is currently requiring. The good news is that those costs are about half of what they were just two years ago, and the cost for UAT ADS-B in for situational awareness and weather has plummeted. Again...we still have SEVEN YEARS to go...

On TIS...I flew about 50 hours in G1000/GTX-33 glass aircraft last year, with both basic TIS and Honeywell systems installed. I also flew a research ADS-B transceiver running both Android phone and Linux PC electronic flight bag applications, and found that the best traffic data was always from the ADS-B system. While TIS has been improved, it is still susceptible to all of the issues noted in the AIM info. None of the three systems showed non-transponder-equipped aircraft, but the portable ADS-B system we used (a non-commercial unit) showed everything within about 60 miles, even though handicapped with a portable antenna system.

Posted by: Todd Stock | September 26, 2012 8:14 AM    Report this comment

No need to hurry out and purchase ADS B out equipment as this will be a way for government agencies to pick up your N number and send you a bill for landing fees, user fees (future) and noise abatement fines to name just a few of the possibilities with this system. Also those users that have or plan on having ADS B in capability only may think twice as to the in-accuracy of "in" only traffic information.

Posted by: Michael Berry | September 27, 2013 2:24 PM    Report this comment

No need to hurry out and purchase ADS B out equipment as this will be a way for government agencies to pick up your N number and send you a bill for landing fees, user fees (future) and noise abatement fines to name just a few of the possibilities with this system. Also those users that have or plan on having ADS B in capability only may think twice as to the in-accuracy of "in" only traffic information.

Posted by: Michael Berry | September 27, 2013 2:24 PM    Report this comment

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