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AVmail: February 14, 2011

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Each week, we run a sampling of the letters received to our editorial inbox here in AVmail. One letter that's particularly relevant, informative, or otherwise compelling will headline this section as our "Letter of the Week," and we'll send the author an official AVweb baseball cap as a "thank you" for interacting with us (and the rest of our readership). Send us your comments and questions using this form. Please include your mailing address in your e-mail (just in case your letter is our "Letter of the Week"); by the same token, please let us know if your message is not intended for publication.

Letter of the Week: GPS Threat Worth Considering

In my opinion (which I believe to be fairly accurate on this subject given my 40+ years experience in electronics), the GPS interference threat posed by LightSquared's proposed network is a serious disaster in the making. Their position that a "properly filtered" GPS receiver won't suffer significant interference is technically true but ludicrous in reality. It's true that the technology exists to produce a filter that greatly attenuates signals in the frequency range they are intending to use while only marginally affecting GPS signals, but in the real world there are many big problems with that "solution."

First of all, such a filter is not trivial to build for a number of reasons, including the fact that the precision required will be costly and subject to diminished performance over time as well as temperature variation. Second, said filter will likely need to be incorporated into the active antennas used by any GPS receiver that uses a remote antenna (e.g. all panel-mounted aviation units). Third, even if said filters were installed for free in all of our airplanes, there's a very good chance that one or more of the powerful ground-based transmitters will drift out of tolerance and start leaking significant emissions inside the GPS frequency band instead of just right next to it per the design. When that happens, there will be mysterious airborne GPS outages that won't be traced to the offending transmitter until a large enough group of reports come to someone's attention who has the knowledge to suspect the real source of the problem. Meanwhile, a bunch of us GPS users willl be wasting money at the avionics shops trying to figure out what's causing the intermittent failures of our equipment.

I predict that the cost to each airplane owner with an onboard IFR GPS will be in the $500-per-unit range, and, as stated above, this only solves the issue if LightSquared's transmitters are carefully monitored continuously with an automatic shutdown in the event of any out-of-band emissions. Seems to me that LightSquared should bear the entire cost of such a retrofit, given that their waiver from the existing rule which eliminated the need for new filtering is the underlying reason for the new expense.

Lance Fisher

I read with great interest the article on the conflict between the GPS system and the proposed LightSquared 4G bandwidth utilization. At the risk of oversimplification, isn't the FAA's NextGen system reliant on the GPS network? If this capability is compromised, how can any tax increases or user fees be justified to pay for any system that relies on it? Shouldn't this conflict be resolved before any further funding of a potentially obsolete system?

David Estus


Aviation and Taxes

I've been in touch with AOPA about their neutral position on this discriminatory tax on Jet A. They seem to have ignored those of us who wish to operate equipment for personal use that are powered with Jet A, such as light turboprops or diesel. With the looming 100LL issue, these powerplants have an increasing place in the GA hangar and will be taxed unfairly as a result of this selective tax. Let all the players pay their fair share into NextGen, airlines especially. Let them use some of their baggage fees to contribute to this new system that will benefit them the most.

Larry Durner


NextGen Funding

What gripes me about this "Question of the Week" topic is the idea that while GA fuel taxes are being raised to fund NextGen, FAA Administrator Randy Babbitt is cutting a check to give JetBlue millions to install ADS-B. I don't see any monetary incentive coming my way to equip my 172.

Add to that the requirement to keep the transponder after the full implementation of ADS-B. Why? Because airline TCAS equipment will become "stupid" without transponders, so we have to pay to maintain equipment for use by the airlines.

Instead, the FAA could allow us to remove the transponder and force the airlines to install a new form of TCAS based on ADS-B, requiring both 1090ES and UAT but that would put the cost burden on the airlines, and that isn't going to happen.

Mike Werner

I would have selected "the fuel tax proposal is appropriate" or similar verbiage if offered on your survey.

Michael Christie

The government has had a free hand with mandates and taxes on aviation. This has caused the cost in real dollars to buy, maintain, and operate airplanes to double over the last 50 years. The result, predictably, is a seriously shrinking industry. This must be reversed. We are already taxed for an aviation infrastructure.

Glenn Hake

How should we pay for NextGen? I question the soundness and vision of the plan for NextGen and the additional cost to GA to participate in NextGen.

Just look at how quickly the FAA threw GA overboard by trashing Loran-C, something that worked and [that] GA could actually use. And, even worse, they threw away E-Loran, which would be much cheaper to operate [and] less susceptible to jamming than GPS, yet almost as accurate as GPS. Remember the wasteful spending the FAA made on the cure-all microwave landing system.

How about all the maintenance costs of the current VOR system? That's where they can really save money. The FAA should redirect the bloated budgets they have and save the things that work.

Donald Stephens


New Eclipse on Right Track

Your suggested answers didn't quite represent my thoughts on the deal with Sikorsky and the future of the Eclipse.

I do think the new owners are on the right track with their product fixes and pricing, and they will get a decent share of the light jet market. However, does that mean the skies are going to be filled with VLJs after all? No. Most of those kinds of predictions were based on the $850,000 price tag, which was ridiculous from the start and which only a few in the press and otherwise had the guts to say so publicly.

John Piper


A Taxing Problem

The video on bonus depreciation is laughable if you are living in Butler County, Kansas. My plane, a homebuilt Zenith 701 light sport, is appraised by the county at $22,500, and they are assessing me $900 per year in property taxes.

I am getting rid of my plane because I can't afford the taxes on a $24,000 annual retirement pension. It would be cheaper for me to rent if I had a current medical, but there are not too many light sport aircraft for rent around here. So I guess I just don't fly anymore.

Michael Sinclair


High-Priced Evacuations

Charging $26,000 to evacuate 350 miles is not something I would want to advertise as a use for general aviation. Capitalizing on the plight of expats is shameful! It equates to piracy in my book, and the spokesperson makes it sound like they are performing some altruistic activity!

Mark Brightman


Springfield's Airport

You have a great publication, and I enjoy reading every issue. Allow me, however, to offer a small correction to your story about TSA Administrator John Pistole blocking further private screeners at KSGF: The airport's name is Springfield-Branson National Airport, not "Branson Springfield Airport." Gary Cyr, our airport director, lives is Springfield (metro population over 400,000) and not 40 miles south in Branson (population about 10,000), where KBBG (Branson Airport, LLC) is located. We're proud of our airport and always appreciate being properly identified!

By the way, is it possible that TSA is a bureaucracy, which doesn't wish to see any part of it shrunk by having private industry do what they do, and do it better?

W.B. Johnson


An Eclipse In St. Petersburg ... In 2008

I remember meeting the then-representative of Eclipse Aviation, Nickolay Nikiforov, in autumn 2008, and he was just showing me the pictures of this Eclipse towed in St. Petersburg during the XII international economic forum.

Ivan Veretennikov


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