ADS-B is coming-What are you doing about it?

[Bill Dunn]

TIS-B makes TIS-A obsolete. It is the same traffic with no radar delay. It uses the same information just faster.

[Releew]

I visited the avionics shop today and he said the same as Bill.  B makes A obsolete.  You can combine traffic systems as in a TCAD application and tie it back to the 530 to work in conjunction with the GDL 88 system.  I have a TCAD application and it's great for vertical separation but no direction indication and limited to two targets. Old but accurate!!!  Personally like having two independent systems for redundancy.  He also confirmed the Radar picture has its opportunities regarding cell tops and color.  There is no configuration screen for this.....  as a matter of fact there is little you can change.  I do not see a setup screen that defines "What is CLOSE, from a converging traffic standpoint."  Firmware updates are continuously being sent from Garmin so I'm assuming this is work in progress!!!  I was surprised how easy it was to do a diagnostic check on the system.  Tech just plugged into a USB extension on the 88 receiver and increased the Audio alert volume with a couple of keystrokes.

 

All in all......  I would do it again, especially if you fly into congested airspace. I live on the Gulf Coast and going to Jack Edwards and Destin on the weekend can be eye opening when you see the amount of traffic on the display that you would NOT normally know is around you......

 

Rick

[BigTex]

No. Your 430 can display only 1 traffic source. You would not want to display that TIS-A if you have TIS-B.

 

I guess my question is that if you go with TIS-B via GDL-88 or other similar products, will you loose your ability to see traffic that's not ADS-B out compliant?

[cliffy]

Here is a link to the best explanation of ADS-B I've found. Several short videos by Free Flight Systems

If you are still in the dark after seeing this ask away here

 

http://adsbuniversity.com/ads-b-university

[Bill Dunn]

Big tex the TIS-B is still just getting a signal from their transponder. Everyone has a transponder so you will see everyone. That is why we tell people to upgrade.

The other person doesn't have to be ADS-B compliant for you to see them.

[bnicolette]

It's going to be interesting to see what happens over the next couple years and what the FAA will allow?

 

http://www.aopa.org/AOPA-Live?cmp=ALTW:L3

[fantom]

With the speed of avionics technology advances, the mandate being more than five years away, and the uncertainty of what the FAA is doing, it's curious how many are jumping on the 'gotta have it now' ADS-B bandwagon. Could it be the CB aspects of getting free traffic and WX, even if they are somewhat inferior?

 

It was amusing to listen to an FAA representative debate and disagree with a KB 'expert' about ADS-B details at the Mooney Summit.

 

I suspect some are suffering from 'premature installation.'

[aviatoreb]

 

With the speed of avionics technology advances, the mandate being more than five years away, and the uncertainty of what the FAA is doing, it's curious how many are jumping on the 'gotta have it now' ADS-B bandwagon. Could it be the CB aspects of getting free traffic and WX, even if they are somewhat inferior?

 

It was amusing to listen to an FAA representative debate and disagree with a KB 'expert' about ADS-B details at the Mooney Summit.

 

I suspect some are suffering from 'premature installation.'

 

 

The weather is inferior.  I have retained my XM weather.  But the traffic seems excellent.  Why do you say it is inferior? I see on my screen what atc sees on their screen.  That was reason enough for me to install now.  Plus I needed a new transponder anyway.

[Mooneymite]

I'm not sure this is up to date since new boxes keep appearing, but it might be of some use if you're like me, just scratching around; there's are IN and IN/OUT sections:

 

http://www.grtavionics.com/adsb.html

[Andy95W]

The weather is inferior.  I have retained my XM weather.  But the traffic seems excellent.  Why do you say it is inferior? I see on my screen what atc sees on their screen.  That was reason enough for me to install now.  Plus I needed a new transponder anyway.

Of course the weather is inferior to XM; it is free and piggy-backs on the limited remaining available bandwidth. Compared to other free sources of airborne radar data, it is awesome, amazing, tremendous, beautifully rendered, timely, and awesome.

Cheap Ba$tard$ unite!

[bumper]

I'm staying on the fence for now. I have 3 aircraft to deal with, and no workable solution I'm aware of for my glider. Unless the FAA gets reasonable about allowing a portable solution, they will decimate soaring in the US. Clueless bureaucrats. 

[ArtVandelay]

I'm staying on the fence for now. I have 3 aircraft to deal with, and no workable solution I'm aware of for my glider. Unless the FAA gets reasonable about allowing a portable solution, they will decimate soaring in the US. Clueless bureaucrats.

You use a glider in class A, B, or C airspace? If not, don't worry about it

[cliffy]

The TSO for ADS-B is long and tedious, I've actually read it all the way through. 

The FAA is tasked with traffic separation. Has to be absolute, no issues, no failures, period. (I'm not trying to defend them, only make a statement.)

 

Right now THEY are responsible for the accuracy of THEIR RADAR systems to accomplish this task (even as limiting as it is in this modern world). They have decades  of experience with it. 

Now they want to move to another platform as far as the PRIMARY data collection on aircraft location goes. From their own"in house" system (RADAR) to a system that they have no direct control over as far as accuracy goes in a failure state. They're wanting to go from a few hundred systems they control (Ground Based RADAR) to a couple hundred thousand airborne systems that they don't own (ADS-B transmitters), They don't give a hoot about the IN side of the equation, it's only fluff to make the mandate more palatable to us, the ones paying for it.) 

Now with them not having DIRECT control over the primary position data that they have to gather, they want/need it to be a closely "controlled" and accurate as they can so as to assure them that the position YOU transmit is accurate. Hence the WAAS mandate. More on this in a second.

 

One item I have not read about yet, and the big hole in the system (and I could have missed it), is the issue of performance checks for the OUT data on a regular basis. For those going the ES transponder route "I presume" that the bi-annual xponder check will verify the ADS-B transmission accuracy. Again, I'm presuming this with no actual reference data that I have read. 

 

On the UAT side, I have seen nothing on an ongoing quality control program for each UAT installation. With the UAT being the PRIMARY device to show the location of the airplane, how long will it be before we have mandated UAT checks just like xponders now? Another expense. If the argument will be that they will compare RADAR target info to UAT received data for accuracy of target, which will they believe? If they fall back to RADAR, what have we gained with ADS-B?

 

i feel (and it's only my opinion right now) that the only reason we have to have WAAS quality EPEs is for their need to locate GROUND TRAFFIC on major airports with pin point accuracy. ALL baggage tugs, fuelers, any and all wheeled traffic on major airports will be required to have ADS-B transmitters (think UATs) so they can be seen on ground RADAR on foggy days.

Do they really need under 100 ft EPEs for airborne traffic? I doubt it. But they do feel they need it for ground based traffic.

To cover their butt for accuracy on every use of ADS-B they went to a "one size covers all" system with WAAS AND a TSO for everything. It protects them legally and us retrospectively.

 

Their responsibility for traffic separation and us "owning" their primary target position system (ADS-B transmitters) is why they will be very reluctant to make any changes to the program as mandated.

 

Do you really think that all those ground based systems will cost  a minimum of $5,000 or $6,000 ?

 

Many of you are young enough to not remember when they went from the very old RADAR systems (WWII types) to the current (I believe it's call ARTS3) that they use now. The costs were staggering but they had to pay for it as traffic separation was their responsibility. 

 

They just shifted the cost of their responsibility to us, to the tune of over $2 BILLION dollars, that's all.

If they want the system for their use, they should be paying for it!

 

Sorry this is so long  Rant over for right now. JMO 

[Cruiser]

I don't understand all the technical aspects of GPS positioning but it seems to me that what ever we have in our airplanes is not the source for position accuracy. It is the GPS signal received from the satellite system.The airplane equipment is merely a repeater, receiving and re transmitting the data. 

so, in my simple mind the receiver in the airplane becomes only as good as the signal it receives. The control and accuracy should be checked at the source. They don't need each and every plane to do that. The satellite system can check itself or there can be some master monitor that alerts when there is integrity issues.

 

The FAA is making this WAY too complicated for what it is suppose to do.

[Oscar Avalle]

I plan to upgrade my transponder to ADS B out next year. Regarding ADS B in I will keep the GDL 39 3 D.

 

BTW will by TCAS still work???

[Cruiser]

Cliffy is right about the en-route stuff. We already have enough equipment to do that now with WAAS GPS. 

 

If the FAA wants airport/ground location, let them develop that system independent of the aircraft. It would seem they could create ground proximity sensors that would monitor all movement on the airport with no input from the moving vehicles. (They should probably check with DHS and just buy the system from them since DHS isn't using it anyway)

 

Of course it is the government, so I should be lowering my expectations accordingly.

[cliffy]

The GPS satellites transmit a signal with timing the receiver decodes the signal from numerous satellites to give a position in space, it doesn't just re transmit a position signal, 

[cliffy]

If the satellites transmitted position to the airplane and the airplane re transmitted that signal to ground- Why not just have the satellite transmit the aircraft position to the ATC?  Because it don't work that way  

[Cruiser]

The GPS satellites transmit a signal with timing the receiver decodes the signal from numerous satellites to give a position in space, it doesn't just re transmit a position signal, 

Why not? Once the aircraft receives the timing signal it only needs to re-transmit it, Let ATC decode and process it.

 

There is nothing in my airplane now (certified WAAS GPS) that modifies or conditions the signal.

 

Why can't those airplanes that don't want GPS for approach or IFR operations just buy a Garmin GPS18x for $59 retail and let FAA do all the integrity checks.

[Cruiser]

In MY system, ATC would receive the signals re-broadcast from all aircraft, check the signal integrity and then if it is OK, that signal would be CERTIFIED for navigation use. IF not, they could notify the pilot of the inaccuracy and act accordingly.

[cliffy]

YOUR system would work IF the system worked that way but it doesn't.

YOUR WAAS GPS takes the signal from many satellites compares the angles received from the base time mark and the variable time hack from each satellite (each satellite position is a known quantity) to compute a position in space of where the receiver is. That position is then displayed on your panel. A basic geometry problem to solve. All the angles when compared to the known position of the satellites converge on your airplane and from that your position is computed by your GPS receiver. 

Now with ADS-B they want us to re transmit that position to them for their ATC separation responsibility.

They even have issues with has fast the re transmit function can happen. They have "latency" requirements for the signal to go from the WAAS motor to and through the transmitter and out the antenna.  This is why ALL ADS-B equipment has to be certified with specific WAAS receivers, UATS or ES transponders as a complete system. We can't just take any WAAS motor and couple it to any UAT or ES xponder and hook it up. The timing of the signal through the entire system has to be certified to be within TSO limits. 

[cliffy]

That doesn't mean I don't like YOUR system!

[fantom]

Food for consideration, particularly for those of you who believe ADS-B is the best thing since apple pie....ADS-B makes user fees much simpler to implement, aids potential terrorists, is far inferior for accurate or complete traffic data, is yet another reason for heads down flying especially in the pattern where most mid-airs occur, and gives the government much more data about you than flightaware ever has. Be cautious, my friends. I found the following on the net, so argue with the author, not me. 

 

 

 

These five stories are set slightly in the future, but only slightly. Perhaps five years from now. The technology described is an accurate portrayal of ATC systems of today, or in the case of ADS-B, an accurate portrayal of systems that are test flying today. The individuals and situations are fictional of course.

 

Scenario One....Terrorism

 

A lone mideast terrorist comes to the United States and purchases (or rents or steals) a light aircraft such as a Cessna 172 or Beech Bonanza or Piper Arrow. While selecting his plane, he is looking for just one item: ADS-B collision avoidance equipment. He knows that ADS-B, installed on all airliners and some business and pleasure aircraft, automatically reports the precise position of the aircraft and also the identity of the aircraft, twice per second.

 

He has no particular target, his only desire is to cause as much fear and destruction and death to The Great Satan as possible. Having waited for a day of poor visibility, he completes his prayers. Then he flies at low altitude and slow speed above the busy highway toward a major airport. He knows that Air Traffic Control radar will not see him because he has disabled his transponder output, thereby assuring that there will be no secondary returns nor any ADS-B transmissions. His aircraft is smaller than the tractor-trailers on the highway below, and the ATC primary radar has been programmed to eliminate highway clutter from the display. He will not be seen.

 

The terrorist also knows that the interval when a large aircraft is most vulnerable is on final approach. It is moving slowly at low altitude, flaps and slats and gear are extended and engines spooled down, this is the point in the flight when the plane is least maneuverable. Using the ADS-B readout to spot his target, he flies up the glideslope and directly toward the doomed airliner.

 

Until the last moment he cannot see the oncoming plane but he knows it is there. The display on his ADS-B is showing its altitude and position with an accuracy of a few meters. The airline crew, monitoring their instruments and complying with pre-landing checklists, never sees him at all. At the last instant he shouts “Allah Akbar” as he flies thru the windshield of the larger aircraft, taking hundreds of people to their death.

 

Scenario Two....Extortion

 

I’ll call him Joe. He is not mentally disturbed, at least not any more disturbed than the average guy in this hurried-up society. His intelligence is above par, it's just that he doesn't have any ethical constraints. Joe might have become a successful bank robber or con artist. But Joe is a loner and has long understood that the cops can't infiltrate a group of one. Plus, he'd rather have 100% of the take than to split it with guys who might get drunk and tell the whole story to some hooker. Joe is sharp on computers and enjoys playing with model airplanes, and would rather be tinkering with technology than shooting pool at the neighborhood bar.

In the vernacular, Joe is a geek.

 

One day Joe reads an article about ADS-B. It tells how the planes are precisely reporting their 3D position, in the clear on 1090 MHz, twice per second. And here's the best part: the identification of the specific aircraft is included along with the position. Suddenly he envisions the whole plan. Extortion! A million dollar bank robbery would be impossible for one man, but a million dollars is pocket change to the airlines. He flips a coin and decides that UAL is his target.

 

The question is, should he ask for the money first and only destroy an airliner if his demands are refused? Or should he begin by dropping one flight unannounced? The former requires credibility, he will have to reveal how he is going to carry out the threat if his demands are not met. This means he will have to disclose some of his ideas and perhaps provide a photograph of his weapon. Worse yet, it requires more than one exchange of information with the airline. After the first letter, the FBI and everyone else will be scurrying to find him. Best to keep the exchanges to a minimum.

 

The latter choice, destroying one plane first to demonstrate his capability, seems more foolproof. He can do that before anyone knows what is going on. Then, if the airline balks on payment, he can threaten to publicize the reason the plane went down and drive their customers away overnight. United might fear the publicity as much as they would fear another crash.

 

Joe goes to work. He builds a model plane, a large one. He has already attended model meets where 1/4 scale planes were flown, he knows that some models weigh nearly as much as a real airplane. Joe's plane will only have one flight, it need not be pretty nor fast nor powerful, its sole purpose is to precisely meet an airliner on final approach while carrying a gallon of gasoline to explode inside the airliner cockpit when the planes collide head on.

 

He doesn't have access to ADS-B equipment, but that doesn't matter. It's a simple task to put a $100 GPS receiver from WalMart in the model plane, coupled to a readily available wireless LAN card. With a similar card in his laptop, he can monitor precisely where his aircraft is. Joe doesn't have a lot of test equipment either, and it might be time consuming to build a 1090 MHz ADS-B receiver from scratch. Instead, he simply takes the receiver from a DBS satellite system he purchased at the discount store for $199 cash. That receiver, half the size of a deck of cards, tunes from 950 to 1450 MHz which is precisely what he requires. All Joe needs to do is write a little software, and voila, he can monitor the exact position and identification of every airliner within 20 or 30 miles.

 

At this point, Joe has been able to do the entire job single-handedly with information and materials that are readily available and 100% legal. While finishing construction of the plane, he spends a few days listening to the tower and watching the ADS-B data on his computer. Soon he has a good list of United Airlines ADS-B ID tags. He is ready to go, and no other person on earth has any idea what is about to happen.

 

Scenario Three....Revenge

 

Thomas Whitten, Ph.D., is a brilliant scientist. He served honorably in the Army during VietNam, finished his education soon after, and has been working for a major pharmaceutical firm ever since. His career reached its peak when he developed the latest miracle drug which will ease suffering and save untold lives worldwide.

“I was a loyal employee” Tom said. “Many of my colleagues jumped from one firm to another, always at an increase in pay. I didn't. I stayed here year after year, decade fading into decade, because I truly believed in what I was doing. For the past 17 years I have been working on a single project, trying to unravel the relationship between DNA and this particular disease. It was rewarding when we made progress, it was discouraging when we didn't, and altogether too much time was wasted cajoling management to fund our work. Several times the project was almost canceled, and each time I managed to convince the executives that we should continue.

 

“And look at the company now. We were the stars of the latest mega-merger, the largest ever in the pharmaceutical arena. Our stockholders made billions, literally billions, because of my work. The CEO himself received a $14 Million bonus, other top management guys received millions more.

“And me? What do they give me? A nice little write-up in the company newsletter, that's what I got. I'm making $94k a year, and when I retire next year I’ll drop to 60% of that. Don't those bastards understand who produced the drug that created all the wealth? Yes, I think they understand. I think they just don't give a damn.”

 

That was all Dr. Whitten said aloud. But the longer he thought, the angrier he got.

It ate and ate at him, eventually reaching the point where he couldn't take it any longer. He briefly contemplated rigging a virus release in the laboratory but that didn't make sense. His fellow workers weren't the problem and he wouldn't do anything to harm them. Management was the problem and they didn't work in the laboratory, they divided their time between the head office in New York and company facilities scattered across the globe. They spent their time flitting from place to place on one of the company jets rather than working...........wait a minute - that's it. The company aircraft! Planes carry top executives. And planes crash.

He established several guidelines. First, his plan must not put him in physical danger. Second, to the greatest extent possible it must not put innocent parties in danger. Third, it must be repeatable because it may take several crashes to achieve the objective. That ruled out trying to plant a bomb on a company aircraft. He might get by with it once - or he might get caught or be blown up in the attempt - and in any event he couldn't manage it repeatedly. Bombs were out, he had to find another way.

 

If there was one thing Tom Whitten knew how to do, it was research. He had no aviation knowledge beyond a lot of coach class business trips and a handful of trips in company jets, plus the little he remembered from his military days. He had no specific knowledge of how to cause a plane to crash but he had faith it could be done.

 

So he went to work. He combed aviation journals at the university. He combed the internet. He kept meticulous notes. Under an assumed name he called various aircraft and avionics manufacturers and interviewed engineers about system specifics. He talked with FAA maintenance personnel too. All the information was there, in the open. It wasn't classified, it wasn't trade secret, it wasn't even company confidential. He asked how a plane was navigated, how it interfaced with Air Traffic Control. He learned what the crew did and what systems they depended on for guidance. He learned what portion of the flight was most hazardous and vulnerable. He studied the localizer and glide slope and marker beacons and DME and GPS and all the rest. He bought a Radio Shack airband radio and became familiar with communications jargon. Eventually Tom found the RTCA documents that contain the standards each navigation system must meet. Every tiny detail was openly available.

 

And he learned about ADS-B. When Dr. Whitten located RTCA DO-242 he knew he had found the mother lode. This was the key to the whole plan. He wanted to destroy specific aircraft while causing no harm to others. ADS-B reports the precise location of the aircraft, in 3D coordinates, and simultaneously reports the identity of the aircraft. That was exactly what his plan had been missing, the means to target a specific plane, and ADS-B provided it.

 

Outsiders imagine that lab researchers spend their days stirring test tubes and peering into microscopes. Once upon a time that was an accurate picture, but electronics is the dominant force today. Tom was skilled in designing instrumentation to solve fresh problems. Now he turned this talent to his new field of interest.

In ADS-B, every plane has a unique 24 bit identifier which remains with the aircraft. In fact, there is an algorithm to convert tail number to ADS-B identification number. It was a simple matter, with binoculars, to get the “N” number of the company jets when they came to town. Dr. Whitten then hand-processed the algorithm and learned the 24 bit ID code of each plane. Now he could receive the 1090 MHz frequency and know which plane was which.

 

His plan was simple. On an instrument landing the plane is following electronic signals. The localizer gives left/right guidance, the glide slope provides up/down information. The former is on VHF, the latter UHF, with the frequencies openly available on aircraft approach charts and other documents. The signals are not encrypted, they aren't even digital. The ILS signal, like most of aviation technology, was established near the end of World War II and long before the invention of the transistor or integrated circuit. Some systems (such as the ancient amplitude modulation used for voice communications) date back far earlier. Aviation is unlike other fields of endeavor because the people who develop the technology are not the people who use the technology. And a third group who are neither skilled in the technology - nor skilled in the use thereof - are the ones who make the decisions. Through the years a lot of wacky decisions have been made. In the case of ILS, the radio carrier is amplitude modulated by two tones, 90 and 150 Hz, which are equal amplitude if the plane is centered on the beam. If a particular aircraft receives a false signal it will follow a false path.

Traditionally the marker beacons, all on 75 MHz, give the pilot an indication when he is nearing the airport but do not allow any sort of readout to the touchdown point, so Tom could ignore them. Often the pilot monitors his Distance Measuring Equipment, DME, to determine his distance to touchdown. Tom reasoned that it would be easiest to simply jam the DME frequency for the critical few seconds. Likewise with GPS, once he had identified his particular aircraft he would jam the very weak Global Positioning Satellite signals on 1575 MHz.

 

None of this was particularly difficult for an experienced researcher such as Dr. Whitten. Indeed, a kid with an interest in ham radio could do as much. But Tom had access to decades of obsolete instrumentation from which he could scrounge the necessary bits and pieces. The ultimate irony, he could use company material to accomplish the objective.

 

It was easy to phase lock the ILS spoofing transmitters to the real ILS signal, from a van parked a mile or so from the airport and under the final approach. He used directional antennas that beamed his signals upwards to the particular flight while anyone else on the approach would receive the proper ILS signal. Phase locking his signals to the actual ILS would assure that there would be no flag or indication when the target aircraft transitioned from the correct signal to the spoof. Sure, it took some effort, but the specifications were all available so it was far easier than other projects he had accomplished.

 

The weather was miserable the night of the first crash. Most flights were landing successfully, but missed approaches weren't uncommon. Some planes were experiencing airframe ice, winds were gusty and unpredictable, the rain was heavy at times, and ATC had traffic backed up halfway to Cleveland. The company Gulfstream IV was making what appeared to be a normal approach when it began to drift to the right. It descended prematurely about a half mile from the end of the runway, struck an embankment at the outer perimeter road, bounced over two maintenance buildings and a communications shack, hit the ground with its left wing, cartwheeled, and burned. All aboard were killed.

 

The NTSB accident investigation concentrated on the navigational aids, aircraft systems, ATC actions, and crewmember performance. The ILS checked out perfectly and no other plane had experienced any ILS problems. The aircraft systems checked out OK, at least the parts that could be reconstructed. ATC had made no blunder and there was nothing on the communications or radar recordings to indicate a problem. Predictably, the crash was blamed on pilot error.

 

But Thomas Whitten, Ph.D., wasn't finished. Several months later, at a different airport, the same pharmaceutical company mysteriously lost another flight.

 

Scenario Four....Data Mining

 

One hot new field in the information age is data mining, extracting and refining nuggets of valuable information from the immense field of electronic data that exists all around us. Some data mining is legal, some is illegal, but most is too new and expanding too fast for any legal or ethical framework to develop. The old fashioned concepts of privacy and ownership are being questioned in ways that were unimaginable 20 years ago.

 

Meet DataMiners, LLC. For a small fee, DataMiners makes it easy for a company to track its fleet of aircraft. Or the fleet of the competitor. For an additional fee, DataMiners will reduce and analyze the information. For instance, the news that the competitor’s bizjet traveled to a specific plant is not particularly useful. But when travel patterns are analyzed and combined with data from other sources, a message emerges that the competitor is having quality problems, or vendor problems, or management problems. Or perhaps the competitor is secretly developing a new product or negotiating a merger. Information like this is quite valuable in the marketplace.

 

Wouldn't a stock trader have liked to know that the Chrysler and Daimler Benz aircraft were visiting the same destination - on the same days - in the months leading up to their merger? Our securities laws protect the market from insider information, but DataMiners LLC is an outsider and whatever they discover is available to the highest bidder.

 

Whether it's a mid sized company or a multinational corporation, conducting business in privacy (and thus traveling anonymously) is essential to survival and maintaining the competitive advantage. In an ADS-B world, the company aircraft will be a liability rather than an asset.

 

The National Business Aircraft Assn, NBAA, has already learned this lesson and has done a complete turnaround from their earlier support of Aircraft Situational Display (ASD). ASD is somewhat similar to ADS-B, it also reports which aircraft is where. But ASD is limited to aircraft operating under Instrument Flight Rules, the data is compiled by the FAA, sensitive data such as military flights is deleted, the position of the aircraft is not sufficiently precise for tactical purposes, and the data is slightly delayed before release by the FAA. (For more on this from NBAA’s perspective, see http://www.nbaa.org/digest/1998/11/opsnotes2.htm and http://www.nbaa.org/pr/1998/98-18.htm .

 

Unlike Aircraft Situational Display, ADS-B comes directly from the aircraft and is freely available to anyone with a 1090 MHz receiver without passing through any agency for filtering or control. ADS-B and efficient use of the corporate fleet are incompatible. If we are promoting aviation for business purposes, we must oppose ADS-B.

 

Scenario Five....User Fees for General Aviation

 

Harvey Patton started his company for the best of reasons. His city was about to close the airport and turn the land into an industrial park. The various factions had fought over this issue for years and Harvey realized that if the airport users were seen to be paying their own way, and perhaps paying a bit extra, then the city could be convinced to keep the airport open.

 

In that light, local airport user fees didn't look so bad. If the fees were structured according to the weight of each aircraft, the bulk of the expense would be borne by the companies that could afford it while the pleasure pilots would only pay a token sum. It sure beat losing the airfield.

 

So Harvey went to the city with this proposal: He would supply and maintain the equipment at no cost to the city, all the city had to supply was a place to house a PC and antenna. The equipment would receive and log the ADS-B signals and routinely modem the data to Harvey's business where billing and collecting would be done. The city would receive 85% of the monthly billings without lifting a finger to do any work. All aircraft activity would be monitored 24 hours a day, 7 days a week whether the tower or FBO were on duty or not.

The city accepted, and the idea worked. Every month the city received a substantial check which went into the airport fund and provided a surplus. Everyone was happy. Well, the users weren't totally happy but they realized it was better than closing the airport altogether. And many users, the smaller aircraft, were escaping user fees by not installing ADS-B. True, not having the collision avoidance equipment meant a higher risk, but many pilots were more concerned with high costs than improved margins of safety.

 

Harvey realized that we are losing an airport a day in the United States and some of those are important GA facilities similar to his airport. He went to those cities and sold the same deal, it was easy to do the automatic billing and collections from his location. He was getting 15% of the take from a number of fields and the revenue began to roll in. Next step was to approach the Westchesters and Addisons all over the country with the same arrangement, every airport needs additional funding and this deal was too good for them to resist. Business increased by leaps and bounds (or takeoffs and landings) and Patton Aviation Revenue was a resounding success.

 

Within a few years Patton equipment was working all over the country. It was installed, it was functioning, it was a proven source of aviation funding. Of course the users were unhappy, particularly at the fields where the fees were set to limit traffic or limit noise or for some other artificial reason. But the corporate users, those who were required to use ADS-B, had no alternative but to pay.

 

Then the new Congress instituted federal user fees for General Aviation. This hadn't happened previously because there was no billing and collecting infrastructure, but Harvey Patton had changed all that. Or more accurately, ADS-B had changed all that.

 

The feds contracted with Patton Aviation Revenue in the same way they contract with Jeppesen or Flight Safety or others who provide a service. Patton did the billing and kept a percentage of the take. Suddenly every takeoff, every flight mile, every landing was computer monitored. VFR or IFR, the airspace bill arrived at the end of the month.

 

The users screamed, they cursed Harvey Patton, but it was no use. If they were going to fly with ADS-B they were going to be billed. Yet the pilots with foresight, those who had never installed ADS-B, weren't paying a cent. Until a court action was filed, that is.

 

The US Federal Court for the Ninth District ruled that all airspace users must be treated equally. The court left it up to the FAA to determine what “equally” consisted of but the edict was firm, equality in user fees had to be maintained.

 

What happened then? There are many possible endings to this story. Maybe each non-ADS-B aircraft received an “average” bill every month whether they flew or not. Or maybe every plane was forced to install ADS-B and the resulting frequency overload created the same situation we've had at Oshkosh for many years: “turn your transponder to standby when 30 miles out”. Then the planes, with their ADS-B turned off, were prohibited from flying in controlled airspace. Or maybe the aircraft owners simply gave up and sold the birds for whatever they could get and pleasure flying died, taking FBOs and manufacturers with it.

Today it is not possible to saddle General Aviation with user fees for one simple reason - there is no infrastructure to collect those fees. The test that aviators must apply to ADS-B (or any similar technology) is simple: Are there any words that Congress could say that will hurt us? If the answer to that question is yes, then pilots and aircraft owners must reject the technology.

 

Proponents of ADS-B tell us that there will be an “anonymous” mode that the pilot can select. But that will be true only as long as the rules permit it. Once upon a time we could turn off the transponder if we wanted to, but as the years passed that choice was eliminated. The same will inevitably be true of an anonymous setting, it can only be used until it is prohibited. First prohibited at flight levels and at major hubs, then prohibited in IFR, then prohibited, period.

 

Proponents of ADS-B also tell us that we can be tracked today. That is somewhat true, but recent experience in the well publicized JFK Jr. accident is instructive. His plane went down around 9 PM Friday and the search and rescue efforts began at 6 AM Saturday. Those efforts continued, under intense press scrutiny, through all of Saturday, all of Sunday, and all of Monday. Around midday Tuesday the FAA finally decoded enoughof their radar tapes to determine the location where the plane went into the water. After the spot was pointed out, the remains of the aircraft were promptly found.

 

It took FAA more than 72 hours to find one aircraft, an aircraft that the President of the United States and the world press corps were actively interested in finding. Given the number of flights daily, it is clear that the FAA does not begin to have the resources to track and bill every flight.

 

Tracking every IFR flight would be somewhat easier, but many of those will switch to VFR if there is a substantial money saving. And if it comes to that, safety will suffer. Isn't safety what ADS-B was for in the first place? Don't you detect something wrong here?

 

This is Who I Am - This is Where I Am

 

Automatic Dependent Surveillance - Broadcast, ADS-B, links an unambiguous “This is Who I Am” with a very precise “This is Where I Am”. Never before in aviation have we put those two pieces of information together and broadcast them in the open for anyone to receive and use as they see fit. We should not do so now.

Decades of ATC experience have proven that identification of traffic is not something the pilot needs. He or she needs to know where the traffic is, which way it is moving, perhaps its size or its speed, but never its identification number. ADS-B flies in the face of this experience.

 

ADS-B has not been widely deployed yet. There is still time to stop it. Most airlines have not invested any money in it yet, nor have the government entities nor the general aviation community. I suggest that it is not in the best interest of aviation to deploy ADS-B in its present form. Like AAS, MLS, and other recent systems, its gestation has exceeded its usefulness. ADS-B made a great deal of sense when it was first proposed. But data processing capability is not the same today as it was twenty years ago. We live in a different technological world now, just as we live in a different political environment.

 

The ADS-B community will laugh off my scenarios. They will explain that identification is necessary in order for aircraft to autonomously interchange information and automatically negotiate evasive techniques. That was true 20 years ago, it is not true today because of the great strides made in computer and DSP technologies. “Not Invented Here” is alive and well in the ADS-B community, these people have devoted major parts of their careers to ADS-B and its understandable that they are unwilling to see their system rejected. Nevertheless, aviation deserves a collision avoidance and traffic management tool that achieves the positive objectives without the serious negatives I have described.

 

Would Anyone Use a Transponder Reply to Destroy an Aircraft?

 

In a word, yes. Litton Guidance & Control Systems makes such equipment and offers it openly on the internet. Read the Litton AN/PPX-3B overview, FAQ, and specifications. A similar Litton product is their TPI-10, here are links to the overview, FAQ, and specifications.

 

If Litton (and their competitors around the world) can do that with a common transponder, think what they can accomplish when ADS-B reports the aircraft's exact identification (not just a squawk code) and simultaneously reports a very precise 3D position!

 

The potential ADS-B threat is immense.

 

 

Why Am I Writing This?

 

My purpose in writing these scenarios is to illustrate the problems that I perceive. I am not delivering a threat, rather I am delivering the message that ADS-B is a threat. ADS-B is a terrorist's dream and security's worst nightmare. I have previously talked with various people within the FAA, with no success. It seems to be a matter of compartmentalization or jurisdiction. I have talked with those charged with “aviation security”, they see their job as one of gates and fences and bomb-sniffing machines. They are not concerned with anything that happens after the wheels leave the runway. I have talked with ATC and ADS-B systems people, they have no interest beyond air traffic control and airspace utilization. I have spoken personally with FAA Administrators Hinson and Garvey.  In essence, the ADS-B security problem falls in an FAA department that hasn't been created yet. In addition, there is a great deal of buck-passing between FAA and ICAO and RTCA and the EU and other participants. No one wants to reject “progress”, and ADS-B inches closer to reality.
 

Am I Shouting Fire in a Crowded Theatre?

 

Is my message "shouting fire in a crowded theatre"? No, it is not. I am shouting the grave potential of fire in a theatre that has not yet been built. There is no danger to the public, nor to the republic, from my message. The danger is within ADS-B itself, and my sole intent is to educate the aviation community as to that danger in time to stop the construction of this dangerous system.

 

My background in this topic comes from a decade of designing, producing and marketing general aviation equipment that receives the 1090 MHz frequency, and as a pilot and aircraft owner with more than 30 years experience. I have learned how easy it is to receive the data, and how much diverse data is available on that frequency. I understand that any data can be used for good or it can be used for evil. And I believe that the systems of tomorrow must be designed with both in mind.

 

Do we need ADS-B?

 

Something like ADS-B is necessary as we move into the future. As aviation matures, there are compelling reasons why we must move beyond a manually operated Air Traffic Control. Traffic density is already straining the limits of what a human-centered control system can accomplish. For the forseeable future there will be a human involved when needed, but the routine separation chores can be handled more easily and more efficiently by technology.

 

So yes, we need an ADS-B sort of system, but without all the negative attributes of ADS-B. Identification is not needed, every databurst will contain a unique identifier within the lat/lon/alt. If two aircraft have the exact same position, they have collided already. Conversely, if they have not collided, by definition they have different positions and thus different and unique identifiers. There is no need for any further ID to permit automated data exchanges between various aircraft.

 

As we move from an old fashioned manual method of sequencing aircraft toward an automated system we must plan for a larger number of aircraft. ADS-B as presently envioned does not have the capacity for tomorrow, in fact it does not have the capacity for maximum situations today such as the EAA Oshkosh event in Wisconsin every August or the Sun'n Fun event held at Lakeland Florida in April of each year. System capacity is an important matter that has been neglected by the proponents of ADS-B.

 

One way to maximized capacity is to limit the quantity of information to only that which is needed. This is a further argument against ID, decades of air traffic control experience have shown that the pilot does not need the registration number of his traffic. Maximizing capacity also argues against the concept of reporting at regular time intervals such as once per second or twice per second. The fact is, aircraft do not collide because of time, they collide because of distance (or rather the lack thereof!). It makes sense for an aircraft that is moving at 600 knots to report every second, but makes no sense whatever for an 85 knot aircraft to report that it has managed to travel a few yards since it's last report one second earlier.

 

A far better idea is for aircraft to report based on distance travelled, such as every 1000 ft. That would provide for six reports per nautical mile while reducing the spectrum usage by a great factor. That same factor would allow for many more aircraft.

 

Besides providing for traffic densities beyond those we experience today, such a system must be robust, it must provide the maximum in operating efficiencies and airspace utilization, it must work equally well at any location whether in radar view or not, it must be able to fail gently and with a maximum of safety margin, it must be sufficiently affordable for all airspace users, and it must do all of these things in a manner that does not aid terrorism nor espionage nor infringe civil liberties.

 

There are proposed systems that provide the benefits of ADS-B without the deficiencies and dangers. The flying community must speak out on this matter, only then will our concerns be heard and acted upon. My goal in authoring this paper has been to aid pilots, aircraft owners, system developers, and the general public in understanding the situation from a viewpoint different from the FAA.

 

Do you disagree? Or agree? Will you participate in a dialog?

 

Most messages I have received in response to this article have said, essentially, that I don't need to worry because there are people taking care of my concerns. I don't buy that argument because the RTCA document defining ADS-B contains all the problems and none of the solutions. On the other hand, there have been a few messages that are both reasonable and articulate, and I'd like to share them with you (click here). If you would like to contribute to the dialog, please email me and I'll post your message.

[ArtVandelay]

I don't need ADSB to take down an airplane unless I was after a particular plane, like Air Force One, talk to anybody who lives next to a class B, it's a target rich environment. So 1-3 makes for a good movie.

For 4, Ever hear of Netjet, you won't tell one from the other, not to mention commercial jets.

For 5, unless I'm going IFR, I just pull the CB while on the ground, once I outside the airport airspace I push the CB in, no problem.

[ArtVandelay]

BTW, don't forget anybody can monitor you radio calls, and with liveatc you can do it remotely.