August 23, 2000 Flight Explorer: Turning the Tables on ATC

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by	Mike Busch

About the Author ... Mike Busch is editor-in-chief of AVweb, a member of the technical staff at Cessna Pilots Association, and in a prior lifetime was a contributing editor for The Aviation Consumer and IFR Magazine. A 6,000-hour commercial pilot and CFI with airplane, instrument and multiengine ratings, Mike has been flying for 36 years and an aircraft owner for 33. For the past 14 of those years, he's owned and flown a Cessna T310R turbocharged twin, which he maintains himself. In his never-ending quest to become a true renaissance man of aviation, Mike's on the verge of earning his A&P mechanic certificate. Mike and his wife Jan reside on the central coast of California in a semi-rural area where he can't get DSL or cable TV.

I've reviewed dozens of new products and services on these pages in recent years, but this one is really special. It's the culmination of a decade-old dream of mine, and I'm tremendously excited to be able to tell you that the dream has finally become a reality.

My dream began in July 1989 when I was attending the EAA fly-in at Oshkosh. I recall walking into the FAA pavilion and seeing something that just blew me away completely. It was a big-screen TV displaying a map of the continental United States on which something like 5,000 little airplane symbols were superimposed. The sign above the TV read "Aircraft Situation Display (ASD)." As I drew closer, I realized that the little airplane symbols were moving, and the FAA gentleman who was manning the exhibit explained to me that I was seeing a real-time display of the entire U.S. air traffic situation!

	Full-US view, with pop-up aircraft information box. (Click on image to view larger screen shot.)
	FedEx aircraft only, with full tags.
	Late-night LAX arrivals and departures, with limited tags..

ATC's Big Picture Show

"Is that what I think it is?" I asked.

"Yes," said the FAA man, grinning like a Cheshire cat.

"In real-time?" I queried.

"Yup," he grinned.

"Where on earth is that coming from?" I asked, mesmerized.

The fellow from the FAA explained that flight plan and radar track data from each of 20 FAA Air Route Traffic Control Centers (ARTCCs) was being transmitted in real-time via geostationary satellite link to the Transportation Systems Center (TSC) in Cambridge, Mass. (now the Volpe Center). A computer system at the TSC merges this data into a single coherent data stream, which is then redistributed by satellite to the Air Traffic Control System Command Center ("central flow control") at FAA Headquarters in Washington, D.C., as well as to the Traffic Management Units (the regional "flow control" folks) at each of the ARTCCs.

The system had been created to provide "the big picture" to the folks responsible for implementing flow control at Headquarters and in the various Centers. And now, a little dish on the roof of the FAA pavilion was making this same real-time air traffic data here at Oshkosh. Amazing!

(Keep in mind that this was 1989, and the Internet was still just a plaything of universities, research institutions, and the military.)

I watched in fascination as the FAA man put the ASD system through its paces. With a few mouse clicks, he quickly zoomed in on the air traffic various areas of the country. By placing a cursor over any aircraft symbol on the screen, he could display all the relevant flight data about that particular aircraft: callsign, altitude, groundspeed, origin, destination, aircraft type, and ETA.

"I wonder how many of those 5,000 airplanes are general aviation?" I wondered aloud. The FAA fellow entered a few keystrokes, and about 70% of the aircraft disappeared from the display. "Looks like about 1,500 of them are G.A.," he said. "Of course, we're only seeing airplanes being tracked by Center, mostly IFRs," he explained.

"Can you tell how many of them are headed for Oshkosh?" I asked. "No problem," he said, tapping a few more keystrokes, whereupon only about 50 airplanes remained on the display, most of them clustered within a few hundred mile radius of OSH.

"I fly a Cessna 310," I told the fellow. "Can we see how many C310s are airborne at the moment?" Within seconds, he'd entered that filter, and I saw that only about 15 of those aircraft were airborne at the moment. "How about 172s and 182s?" About 60 and 40 of those, respectively, were in the air and being tracked by ATC.

"Wow, that's incredible!" I said, my mind racing. "I don't suppose that if I put up a satellite dish at my house, I could receive and display the same data on my PC?" The FAA man smiled and shook his head. "This stuff is strictly for internal FAA use only," he told me, explaining that the satellite transmissions were encrypted to ensure that unauthorized folks couldn't intercept them.

The seed was planted. But it would take ten years, an act of Congress, the Internet explosion, and some tricky negotiations before my dream would be realized.

Forbidden Fruit?

Apparently, I wasn't the only one who was blown away by this technology. The airlines were very interested, too, and made a big pitch to the FAA to allow them access to the ASD data in order to help improve flight scheduling and keep tabs on delays. In a moment of weakness, the FAA agreed, and decided to make ASD data available to the airlines under a program known as Collaborative Decision Making (CDM).

At this point, several alphabet groups representing general aviation constituencies — including NBAA and AOPA — went to the FAA and said, "hey, if the airlines can have access to ASD data, then we want it, too." To which the FAA replied, "Sorry, Charlie!" Apparently, the ATC folks had fits over the idea that civilians might "look over the shoulders" of air traffic controllers, concerned that they might start receiving phone calls saying, "Hey, I was watching LAX arrivals on my ASD display, and it sure looked to me like you let Delta get awfully close to TWA..." Meanwhile, the FAA security folks freaked out at the notion that "just anyone" could have access to the exact location of any particular airplane at any given time. So the FAA told the G.A. groups, "No way, Jose!"

Fortunately, the G.A. folks didn't take this lying down. They were convinced that they were entitled to have access to this information under the Freedom Of Information Act. They took this argument to Capitol Hill, and managed to convince Congress, who in 1992 told the FAA that they had to make the ASD information available to any legitimate aviation user who requested it.

The FAA was definitely not thrilled about this mandate, and did its best to drag its feet implementing it. The FAA is pretty good at foot dragging, and managed to put off the inevitable for nearly five years. Finally, in the spring of 1997 the agency started making filtered ASD data (minus military and certain other highly-sensitive aircraft) available to anyone who signed a letter of agreement (LOA) and was willing to pick up the data feed at the Volpe Center in Cambridge, Mass. Thus was born "Aircraft Situation Display to Industry," known by the acronym ASDI.

There are now something like a dozen different vendors that have signed LOAs with the FAA and are offering services based on the ASDI feed. They include everything from free Web-based sites that allow checking on the current position of a particular scheduled airline flight, all the way to highly sophisticated services designed for airline dispatchers and large corporate flight departments.

DI's Remarkable "Flight Explorer"

By far the most exciting ASDI service I've found is something called "Flight Explorer" from Dimensions International (DI), an aviation consulting firm headquartered in Alexandria, Va., with over 350 employees and 24 offices, specializing in information technology engineering and air traffic control systems. When I first saw FE in 1997, it absolutely knocked my socks off. Since then, the company has issued several updates and made the product even better. It offers all the capability that I saw during that ASD demo at Oshkosh, plus a great deal more. Best of all, it does it right on your own PC, and does it anywhere you have access to the Internet.

Flight Explorer (FE) is implemented as a highly specialized client software package that runs as an application under Windows 95, 98 or NT 4.0. (Sorry, Macophiles...you're out of luck.) Before you can use FE, you have to subscribe to the FE service and receive a user ID and password. Whenever you launch the FE software, it asks you to log on, then contacts the FE server over the Internet.

	Initial world view, with pop-up "hot tip" box. (Click on image to view larger screen shot.)
	To zoom in, simply drag mouse over desired region.
	U.S. view with ARTCC boundaries enabled. (Very late at night!)
	Northern Arizona with VORs, airways, and a/c tags.
	Real-time NEXRAD  weather radar overlay and frontal boundaries (FE Professional only).

Assuming your login is successful, you'll see a world map with 6,000 or so little turquoise dots on it representing the actual current positions of all tracked aircraft presently in the system. As you watch, you can see the dots (airplanes) moving in real-time.

Now, using the mouse, move the cursor arrow to point at any of these dots. Up will pop a little data block giving the flight's identification (callsign), altitude, groundspeed, aircraft type, origin, destination, departure time and ETA. In addition, you'll see a line that goes from the flight's current position to the location of its destination.

But that's only the beginning. FE also lets you:

• Zoom in on any desired geographic region.
   
• Customize the base map by selectively adding navaids, airports, airways, intersections, special-use airspace boundaries, ARTCC boundaries, ATC sector boundaries, a lat/lon grid, airport range rings, and much more.
   
• Define one or many "filters" that determine which aircraft are to be displayed. You can filter on aircraft ID (including airline prefix), origin, destination, aircraft type, altitude range, or any combination of these criteria. You can define multiple filters, each with an associated display color. (E.g., you can choose to display high-altitude aircraft in green and low-altitude aircraft in blue; or UPS flights in brown and FedEx flights in purple.)
   
• Add tags (data blocks) to the displayed aircraft, with or without leader lines, and customize the contents, color and font size of those tags. Tags may be applied to all aircraft, individual aircraft, or groups of aircraft that meet specified filter criteria.
   
• Display history trails for aircraft, showing the last several known positions. Trails may be applied to all aircraft or only selected aircraft.
   
• Display velocity vectors showing where the aircraft is projected to be in a specified number of miles or minutes. Again, these vectors may be displayed for all aircraft or selected aircraft.
   
• Once you've got the display zoomed, overlaid, filtered, tagged and embellished exactly the way you want it, save all those settings as a user-defined "view" so that you can instantly return to it (or any other of your saved "views") with just two mouse clicks.
   
• Look at real-time graphs of departure traffic and proposed and actual arrival traffic four hours into the future at major airline airports.
   
• Display or print a scrollable "flight list" containing all tracked flights presently in the system, sorted by callsign, aircraft type, origin, destination, groundspeed or altitude.

And those are just the standard features of FE. A host of additional optional extra-cost features are available, including:

• Real-time graphical weather overlays and weather alerts.
   
• Textual and graphical display of aircraft flight plan information and flight plan amendments.
   
• The ability to record ASDI data to a disk file, and then play it back later at up to 99 times original speed.

How good is FE? Well, let me put it this way. For most of my adult life, I was a professional software designer and developer. A pretty damned good one, I might add (in all humility). As a result, I've seldom come across a piece of software I didn't feel could use some improvement. But FE is an exception. After dissecting FE and putting every feature through its paces, I concluded that had I written the specifications for the product myself, it wouldn't have turned out nearly as good as what DI produced.

FE is that good.

So What's The Catch?

When I first saw Flight Explorer in 1997, it was instantly apparent that this was the capability I'd been dreaming about ever since I first saw that ASD demo at Oshkosh eight years previously. I wanted it, and I was sure any other pilot or aviation enthusiast who saw it would feel exactly the same way. "So what's the catch?" I asked my contact at DI. (There's always a catch!)

The catch turned out to be prefixed by dollar signs. It turned out that the subscription fee for the FE service was about $250 a month. Now, that was a drop in the bucket for the customers that FE was designed for — airlines, corporate flight departments, major FBO chains, etc. — but it was pretty much out of the question for an individual pilot or aircraft owner like me.

Rather than throw up my hands in frustration, I decided to approach the top management of DI with a proposal. I explained that I was editor of the Internet's leading aviation magazine and news service with more than 100,000 subscribers — mostly pilots and aircraft owners — and that I was convinced that many thousands of them (perhaps tens of thousands) would be just as enthusiastic about FE as I was ... if the price was affordable enough. Like maybe $10 or $20 a month instead of $250.

The powers-that-be at DI were intrigued with this idea, but also understandably gun-shy. On one hand, if I was right that a big "low-end" market existed for ASDI services, they were certainly interested in addressing it. On the other hand, they couldn't afford to jeopardize their existing FE business base by cutting the price of their service by 95%. What was needed, we all agreed, was to define a low-end product (ultimately dubbed "Flight Explorer AVweb Edition") that would meet the needs of individual users like me but not of DI's major corporate customers.

For nearly a year, we iterated back and forth with proposals and counterproposals, trying to come up with a subset of FE features that would appeal to individual users but not compete with the existing professional-oriented product. But despite our best efforts, we never were able to come up with a satisfactory compromise. All of DI's proposals called for crippling FE to an extent more than I thought acceptable, and all of my proposals called for a feature set that was too rich to give DI the comfort level they needed that they would not be "eating their young" by introducing a low-cost FE product. Clearly, we were getting nowhere.

Finally, we sat down face-to-face at Oshkosh '98 to take a fresh look at the problem. We realized that what differentiated individual and professional users of ASDI was not so much features as it was usage. Airline users typically used FE to monitor and track their flights 24 hours a day, seven days a week, while corporate flight departments needed the capability at least eight hours a day. In contrast, my expectation was that most individual users would probably not use FE for more than five or ten hours in an average month ... twenty hours at the outside.

Consequently, I proposed to the DI folks that they consider offering FE on a pay-as-you-go basis, priced such that an individual user who used the service for 10 hours a month or less would be charged just 10 bucks, while a corporate or airline user that used the service 40 hours a week or more would be better off with the $250/month unlimited-use plan.

FE AVweb Edition

DI mulled over the idea for a few months, made a few modifications and refinements, and finally gave it their blessing. And thus, "Flight Explorer AVweb Edition" was born.

At first glance, the fee schedule FE AVweb Edition looks a little odd. A basic subscription fee of $9.95 covers up to 10 hours a month of usage, for an average cost of just under a dollar an hour. Monthly usage in excess of 10 hours is charged at $1.95 an hour, up to a maximum of 50 hours. If you use more than 50 hours in a month, the fee goes up to $3.49 an hour for any hours beyond 50. This may seem weird, but there's method in DI's madness: They want to make certain that any customer who typically uses the service for more than about 50 hours a month stays with the flat-rate $250/month service (which is now called "Flight Explorer Professional" to differentiate it from the new AVweb Edition). If you do the math, you'll see that FE AVweb Edition's "regressive" fee schedule (the more you use, the higher the hourly cost) accomplishes precisely that: The breakeven point is between 50 and 100 hours a month.

DI was also concerned that if FE AVweb Edition turned out to be as popular as I predicted, the demand might overwhelm their server capacity and technical support capability. Consequently, a separate dedicated server was set up specifically for AVweb Edition customers, located at AVweb's server site at Boca Raton, Fla., and utilizing our high-capacity connection to the Internet backbone. Also, a decision was made that technical support for AVweb Edition customers would be handled via same-day email rather than by telephone.

Finally, DI decided that a few optional features — mostly those with high bandwidth requirements or primarily of interest to high-ultilization customers — would not be made available in FE AVweb Edition: real-time weather overlays, flight plan retrieval, and record/playback.

But with those few exceptions, FE AVweb Edition offers the full functionality of DI's professional airline/corporate product, but priced at a level that virtually every pilot, aircraft owner and serious aviation enthusiast can easily afford: $9.95 a month. Personally, I think it's a helluva good deal.

A Closer Look At FE

Now that you know what FE costs, let's take a closer look at how it works. It's a highly visual product, so the explanations below are illustrated with small "thumbnail" screen shots of FE in action — click on any of them to view a larger, high-resolution version.

Getting started with FE AVweb Edition couldn't be simpler. You can sign up for the service at the Flight Explorer AVweb Edition web site by completing a secure online order form which includes your email address and credit card info. Your FE account is activated instantly, and you can download the FE AVweb Edition client software from the same site. The client software is about 3.8 megabytes long, so downloading over a 28.8 Kbps dial-up connection will take 20 minutes or so.

Once you've got the file, installing it under Windows 95/98/NT is pretty much like any other 32-bit Windows application: You simply double-click on the install file to launch it, and a standard InstallShield installer walks you through the installation. The package includes its own "uninstaller" to make it easy for you to remove FE from your computer at a later time, should you wish to do so.

The only unusual aspect of the FE installation process is that the installer prompts you for an installation "codeword" before it will perform the installation. The codeword is emailed to you when you sign up for the FE service.

Logging on to Flight Explorer.

Once you've installed the client software on your computer and signed up for the service, you're ready to start using FE. The first step is to launch the FE client just as you would any other Windows program (from the Start/Programs menu or the desktop). FE starts by putting up a dialog box that asks you to log on with the FE user ID and login password that you received when you signed up for the service.

After you've entered your login credentials and clicked the "Connect" button, the software establishes contact with the FE server over the Internet to authenticate your login and start your FE session. This process normally takes no more than a couple of seconds.

Initial world view. (Click on image to view larger screen shot.)

Once your login has been authenticated, FE displays its default world map, and starts downloading its initial aircraft, track and flight plan information from the FE server, a process that typically takes about a minute (depending on how many aircraft are flying and the speed of your Internet connection).

As this initial data is downloaded, you'll see the world map become populated with thousands of dots that represent aircraft positions — around 6,000 of them on a typical day, more on a holiday weekend, fewer late at night. At present, you'll see those dots only over North America, the U.K., and major north Atlantic and Pacific oceanic routes. You can expect the rest of Europe to be added soon as the EU gets its ATC automation act together.

As you watch, you'll see that the dots (airplanes) are moving in near-real-time. I say "near" because although the FE server provides position updates every 10 seconds, the FAA presently provides position updates for each individual aircraft much less frequently than that. The ASDI data feed may update the position of a particular aircraft as infrequently as every four minutes, although the FAA is already moving to a one-minute update cycle, especially in busy TRACON areas. (Remember, the FAA is providing this data for the benefit of their own flow control folks — we're just looking over their shoulders via the Internet.)

	Simply drag mouse to zoom. Result shown below. (Click on image to view larger screen shot.)

While this "big picture" view of world traffic is certainly fascinating, it's obviously too cluttered for most practical purposes. Most of the time, we're interested in focusing on a much smaller geographic area.

FE allows you to zoom in on any region of interest by simply dragging a rectangle over the area with your mouse. Starting from the default worldwide view, this is typically a two- or three-step process. For instance, if I'm interesting in watching the arrivals and departures at DFW, I'll probably first drag a rectangle over the continental U.S. in order to get enough map detail to see the state boundaries. Then I'll drag a rectangle over Texas to zoom in close enough to make out exactly where Dallas is. Finally, I'll drag a 50 NM square centered on DFW to get a nice, close-up view.

If the view isn't centered exactly the way you want it, you can use the horizontal and vertical scroll bars to adjust the view window in any direction. There's also an option that causes the view to be centered around any point you identify with a mouse click. If you've zoomed in too far, you can use the "Zoom Out" button on the toolbar to back up one or more zoom levels.

	FE's map overlay toolbar lets you control exactly what appears on the display.
	ARTCC boundaries are shown here in magenta. Individual sector boundaries and special-use airspace may also be displayed.
	Here, navaids, airways and ATC sector boundaries are shown, plus range rings surrounding DFW.
	Real-time weather overlays are available only in FE Professional.

FE's toolbar allows you to customize exactly what features are depicted on the display. The following overlay controls are available:

• Planes: This tool turns controls the display of aircraft, and has a drop-down menu that lets you select what elements are added to the basic aircraft position symbol. You can enable or disable tags (data blocks), track history (where the aircraft has been), velocity vectors (where it's going).
   
• Center Boundaries: This tool controls the display of ARTCC boundaries.
   
• Sector Boundaries: This tool controls the display of individual ARTCC sector boundaries, and has a drop-down menu that lets you specify whether you want to see low-altitude, high-altitude, or ultrahigh-altitude sectors (or any combination).
   
• Special-Use Airspace: This tool controls the display of special-use airspace, and has a drop-down menu that lets you select which types of SUA you want displayed (MOAs, prohibited, restricted, warning, alert).
   
• Airways: This tool controls the display of airways, and has a drop-down menu that lets you specify whether you want to see low-altitude airways, high-altitude airways, or both.
   
• Lat/Lon Graticule: This tool controls the display of a latitude/longitude grid.
   
• Airports: This tool controls the display of airports, and has a drop-down menu that lets you specify which categories of airports you want displayed (pacing, major, other, non-USA).
   
• Fixes: This tool controls the display of fixes (intersections), and has a drop-down menu that lets you specify whether you want to see low-altitude fixes, high-altitude fixes, or both.
   
• Navaids: This tool controls the display of naviads, and has a drop-down menu that lets you select which kinds of navaids you want displayed (NDB, VOR, TACAN, etc.).
   
• Radar Sites: This tool controls the display of ATC radar sites, and has a drop-down menu that lets you select which classes of radar sites you want displayed.
   
• Weather: In FE Professional, this tool controls the display of real-time weather overlays, and has a drop-down menu that lets you select which kinds of weather you want displayed. (In FE AVweb Edition, this tool is grayed out and unavailable.)

Tags may be displayed for all aircraft, or just selected ones. You can control the size and content of the tags, turn leader lines on or off, and even reposition tags for decluttering.

A "tag" is a block of textual information that is attached to (and moves with) an aircraft symbol. Flight Explorer uses tags that are patterned after — and very similar to — the "data blocks" which appear on an ATC scope.

By default, each tag is attached to its aircraft symbol by means of a "leader line," and contains the aircraft callsign, altitude, groundspeed, departure point, destination, aircraft type, and ETA. However, you can customize the tags by eliminating the leader line and/or various data elements, and you can specify the color and font size to be used.

You can ask FE to display tags for all aircraft on the display. However, unless you're zoomed in fairly tightly (or have a very high-resolution display), there may be so many aircraft on the screen that the tags may start to overlap and become difficult to read. If this occurs, you also have the option of enabling tags only on certain individual aircraft of interest, or (using filters) on specified groups of aircraft (e.g., all Learjets above FL350, or all UPS flights bound for Louisville).

This defines a "quick filter" that displays all FedEx aircraft bound for Memphis in magenta. It can be combined with other filters (up to 50 may be active).

By default, FE displays all tracked aircraft in the geographic area that you're viewing. Filters permit you to limit the display to some particular group of aircraft that may be of interest, or to highlight a group of aircraft by displaying them in a special color or identifying them with a tag.

The simplest way to create a filter is by clicking on the "Quick Filter" button on the FE toolbar. This brings up a dialog box that prompts you to define the group of aircraft you're interested in by specifying one or more of the following filter criteria:

• Aircraft ID, which may be a full callsign (e.g., "N2638X") or a partial one followed by the wildcard character asterisk (e.g., "FDX*" to select all FedEx flights).
   
• Origin airport identifier.
   
• Destination airport identifier.
   
• Aircraft type, which may be a full aircraft type identifier (e.g., "C310") or a partial one followed by the wildcard character asterisk (e.g., "BE3*" to match Beech 33-, 35- and 36-series Bonanzas).

The Quick Filter dialog also allows you to specify the color used to display aircraft that are selected by this filter.

Once you’ve defined the filter criteria and display color, you may activate the filter by clicking on either of two buttons:

• Add to existing filters causes this filter to be added to a list of previously-defined filters. For instance, if you're viewing traffic in the DFW area, you might set up one filter to display DFW arrivals in green, a second filter to display DFW departures in red, and a third filter to display overflights (neither landing at nor departing from DFW) in blue. FE lets you have up to 50 filters active at one time.
   
• Replace existing filters deletes any previously-defined filters and activates this filter as the only active filter.

Here's a fancy filter that color-codes LAX arrivals by altitude, and adds tags to those below 10,000 feet. The possibilities are endless.

Quick Filters handle the most common filtering requirements, but if you really want to get fancy, you can used the Advanced Filters screen to exercise even greater control over the filtering process. With this capability, you can:

• Filter on altitude range.
   
• Create a "not" filter which matches aircraft that don't meet the specified criteria.
   
• Specify that aircraft meeting the filter criteria should be tagged.
   
• Change the order in which the various active filters should be applied.
   
• Add, delete, or edit any filter in the list.

As you can see, FE filters are incredibly powerful and flexible. Once you get the hang of using them, the possibilities are limited only by your imagination.

You can save your favorite FE displays as user-defined "views" and then call them up at will with just two mouse clicks.

The ability to define "views" is one of the most powerful features of FE. Once you've customized a FE display just the way you want it — zoomed in to exactly the area you want to watch, overlaid with exactly the map items you want, and aircraft filtered and tagged the way you want them — you can save all these settings by clicking on the Create View button on the FE toolbar and then giving the view a name (e.g., "DFW arrivals/departures").

You can define any number of views this way, then switch from one to another with just two mouse clicks. Simply click on the Select View button to bring up a list of named views, then click on the desired view.

If you want to modify any of the settings for a view, just make the changes and then click on the Update View button to save them.

One of my favorite pastimes is to watch traffic in the low-altitude sector of Los Angeles Center that lies over my house, while simultaneously listening to the corresponding Center frequency (119.05) on my aviation scanner. I zoomed FE so that this particular sector occupies the full screen, turned on tags for all aircraft, turned on overlays of airports, navaids, sector boundaries and special-use airspace, and set up a stack of filters to color-code the aircraft by altitude. Then I saved all these settings in a view called "ZLA 119.05 Sector" so I can return to these exact settings any time I want to.

	Pointing to any aircraft symbol brings up this "hot tip" box with flight info.
	Right-click on any aircraft symbol to bring up this pop-up menu..

Frequently, when watching an FE display, you'll see a particular aircraft that you'd like to know more about. If you point at that aircraft with the cursor arrow (using your mouse), FE will draw a little "selection circle" around the aircraft symbol, will draw a "destination line" from the aircraft to its flight planned destination, and will pop up a little "hot tip" box that contains that aircraft's callsign, altitude, groundspeed, aircraft type, origin, departure time, destination and ETA.

If you decide you'd like to keep tabs on that particular aircraft, you can right-click on it. This will bring up a little pop-up menu that lets you:

• Add a tag to the aircraft. Tags normally appear below and to the right of the aircraft symbol, but you can reposition the tag anywhere you want by holding down the right mouse button and dragging the tag to the desired position.
   
• Add a history line to the aircraft. This shows the last four reported positions of the aircraft.
   
• Add a velocity vector to the aircraft. This projects where the aircraft will be in a specified number of minutes (or miles).
   
• Pop up a properties box that shows everything that is known about the aircraft.

At major air carrier airports, the FAA furnishes projections of arrival and departure traffic. Flight Explorer can access this information and display it in graphical form. Simply right-click on the airport you are interested in, then select "Graph future traffic" from the pop-up menu.

The future traffic graph shows the projected arrival and departure traffic for each five-minute interval for the next four hours. By default, arrival projections are shown in two categories: those aircraft actually in-flight (for which the projected arrival time is known within close tolerances), and those who haven't departed yet (for which the projected arrival time is based on the proposed departure time). However, you can click a checkbox and combine all departures (in-flight and proposed) into a single combined total on the graph.

Flight List

Clicking on the "ACType" button sorts the flight list by aircraft type, making it easy to look for all aircraft of a specific type (like Cessna 310s). You can sort the list by any other column, too — callsign, origin, destination, etc.

Want to see if your buddy's Belanca Super Viking is airborne, but forgot the tail number? Need a list of all flights bound for a particular airport? Curious how many aircraft are cruising above FL400, and what types they are? Looking for the supersonic Concorde but don't remember its aircraft type code? No problem!

Click on the Flight List button on the FE toolbar to bring up a scrollable columnar list of all tracked aircraft in the system. Then click on the applicable column heading to sort the list by aircraft ID, origin, destination, aircraft type, altitude, speed, departure time, ETA, or status. You can also print a hardcopy of this list by clicking on the Print button.

If you find an interesting aircraft in this list and want to locate it, simply right-click on the Flight List entry and select "Display Tag" from the pop-up menu. The selected aircraft will be tagged on the FE map display. You can even select multiple aircraft on the Flight List (e.g., all Cessna twins, or all aircraft flying to Des Moines) and turn on tags for all of them at once.

If you sort the flight list by aircraft ID, you'll sometimes notice a handful of aircraft (almost always bizjets) whose callsign appears as "BLOCKED." These are aircraft whose operators have requested that their callsigns be blocked from view through a voluntary program coordinated by NBAA. The Flight Explorer service cooperates with this program by blocking the identification of these aircraft. They are still tracked as usual by Flight Explorer — only the N-number is supressed.

Okay, It's Cool ... But Is It Useful?

If you've read this far, I hope I've convinced you that FE is a magnificent piece of software. The question remains whether it's actually useful for something, or just a really cool toy for aviation enthusiasts.

Now, I'm not about to stand here and tell you that FE is something no pilot can live without. But in the nearly two years I've been using it, I've found it quite useful, immensely educational, and an awful lot of fun, too.

Tracking AVweb Executive Editor Jeb Burnside on a flight from Leesburg, Va, to Asheville, N.C. in his Beech Debonair. Looks like he's climbing through 8,000 feet at a groundspeed of 153 knots, and his ETA at Asheville is 1838Z..

The most obvious use of FE is to track the location of a particular flight of interest. Now, if all you're interested in tracking are scheduled air carrier flights, you probably don't need FE — you can do it with a free Web-based tracker. On the other hand, if you want to track general aviation flights, or keep track of several aircraft at once, then FE is the way to go.

When friends fly in to my home airport of Santa Maria, Calif., for a lunch meeting or visit, I use FE to check if they got off on schedule. By the time I leave for the airport to pick them up, I know when they'll be touching down almost to the minute. The cost of doing this is trivial: about 25 cents for a 15-minute FE session.

And when I use my airplane to travel, FE allows my family and business colleague to keep track of exactly where I am and when I'll arrive at the next stop on my travel itinerary. If I'm held up by weather or ATC delays, they can see that I'm running behind schedule, and are spared any needless worry.

Of course, if you need to keep track of more than one aircraft, FE really shines. It's provides a splendid tool for flying clubs, flight schools and FBOs to keep track of where their airplanes are and when they'll return.

During the 1998 Cayman Caravan, 150 GA aircraft (mostly singles) flew from Key West, Fla. (EYW), to Grand Cayman, B.W.I., crossing Cuba about 50 nm east of Havana (UHA). Unfortunately, we couldn't track them into Cuban airspace. Maybe next year. (Click on image to view larger screen shot.)

For anyone involved in organizing a fly-in event, FE is a terrific tool. For the past couple of years, I've used it in connection with the annual "SMX-GIG" fly-in held each April at my home field. Using FE, we can keep track of the inbound aircraft, tell who'll be arriving soon, and make sure that we have a welcoming committee and ground transportation present for any stragglers who are arriving late.

For the past three years, I've participated in the annual Cayman Caravan in June during which 150 or so general aviation airplanes join up at Key West, Fla., and then caravan through the Giron Corridor over Cuba to Grand Cayman for Cayman Islands International Aviation Week. The Caravan is meticulously organized, launching groups of four aircraft from Key West every 15 minutes. I use Flight Explorer on my laptop computer to monitor the Caravan departures and make sure everything's going smoothly. What a gas!

(Unfortunately, Cuban ATC is not tied into the ASD system yet, so the aircraft drop off the FE screen shortly after they enter Cuban airspace. Maybe next year...)

This year, I was asked to fly down to the Caymans a day early to transport some of the Caravan staffers who needed to be at Grand Cayman to meet the early arrivals. But since Internet access from the Caymans is excellent (and inexpensive), I was actually able to use FE to monitor the progress of the Caravan from my hotel room on Grand Cayman's Seven Mile Beach. The cost: a few bucks. What astonishing technology!

Sure, FE can be very useful. But it's also a lot of fun, and a great way to become familiar with ATC procedures and air traffic flows in various parts of the country (and the world). At just a dollar or two an hour, there's no reason not to have fun with it — it's probably the cheapest entertainment in aviation.

A few real-time ATC audio links New York NY (Kennedy Tower) Dallas-Fort Worth TX Chicago IL Santa Ana CA Omaha NE Abilene TX Providence RI

I find it fascinating to spend 30 minutes or so watching air traffic with FE while listening to the ATC air-to-ground communications. At first, I did this just in my local area, tuning my aviation scanner to the local Los Angeles Center frequency while watching the activity in that sector with FE.

After awhile, I realized that I could do the same thing in various other parts of the country. The ATC audio for several major terminal areas (including DFW and ORD, for example) are broadcast over the Internet as streaming RealAudio feeds. Even with a lowly 28.8 Kbps dial-up connection to the Internet, I find that I have no problem listening to these audio feeds while watching the corresponding airspace with FE. The experience is almost like sitting at a scope in the TRACON and plugging in with the controller. The biggest difference is that you can do it at your convenience, at home, wearing a bathrobe and slippers!

A nightly FedEx "push" into Memphis. Here, we've filtered only FDX flights with destination MEM, and we've supressed the airline ID and leader lines from the tags. (Click on image to view larger screen shot.)

As FE gains in popularity (as I'm convinced it will), ATC audio from more and more locations will be made available via the Internet. I expect to see audio feeds from New York, Los Angeles, Atlanta, Washington D.C., and other major hubs available online before the year is out.

Speaking of fun... If you're a night owl like I am, try monitoring the flow of the package express airlines with FE one night. As the volume of other air traffic is rapidly diminishing, you'll see dozens of FedEx aircraft converging on Memphis, and dozens of UPS planes headed for Louisville. Things subside for awhile as the packages are sorted in the two huge facilities. Then, in the wee hours of the morning, departures erupt from MEM and SDF as if someone dropped a hand grenade in the middle of a crowded restaurant. Later, if you're still watching as the sun starts to come up, you'll see what seems like countless C208s (Cessna Caravans) launching from the regional freight hubs toward outlying destinations throughout the country. It's quite a sight! If you watch the whole thing, it'll cost you the price of a movie theater ticket...and it's worth it.

Signing Up For FE

Signing up for FE couldn't be easier. Just go to the Flight Explorer AVweb Edition web site, fill out the secure online signup form with your name, address, phone, email and credit card information, and then download the FE client software over the 'net. As soon as you sign up, you'll be sent an automated email containing instructions (and the necessary codeword) for installing the FE client on your Windows 95/98/NT computer and for logging on to the FE server. And you're off and running.

The basic service costs just $9.95 per month, billed to your credit card, which includes up to 10 hours per month of flight tracking services. If you exceed 10 hours per month, additional hours are charged at $1.95/hour up to 50 hours/month, after which the cost increases to $3.49/hour.

Each billing cycle is 31 days, starting on the day you sign up. At signup, your credit card is initially billed $9.95 for your first 10 hours. At the end of each 31-day period, you will be billed for any usage above 10 hours that you used during the previous period, plus $9.95 for the first 10 hours of the next billing cycle. Session times are measured in one-minute increments, with a minimum charge of 15 minutes per session. In other words, for session that last less than 15 minutes, you are charged for a quarter-hour, but for longer sessions you are charged by the exact minute. You can check the billing status of your account online, and you can also cancel your service online at any time.

If you're a business user who needs round-the-clock tracking, real-time weather overlays, access to flight plan data, or the ability to record and play back ASDI tracking data, you may be a candidate for Flight Explorer Professional. If so, just use the FE Professional query form and someone from Dimensions International will contact you by email.

If you sign up for either service (FE AVweb Edition or FE Professional), I'd love to hear how you like it, how you use it, and any neat tips or tricks you've found that other FE users might find helpful. Just drop me an e-note.