New JoNES article to shoot down: Transponder Activity

[Oystein]

After two years in hibernation, Kevin Ryan's "Journal of 9/11 Studies" has published a new article:

"Implications of September 11 Flight Transponder Activity" by Aidan Monaghan, May 2017.

Abstract:

It has been the consensus of informed observers that the loss or alteration of Secondary Surveillance Radar (SSR) information for the four September 11 flights was caused by accused hijackers allegedly seizing control of the aircraft flight decks and manually turning off or adjusting each plane’s Mode S (Mode Select) transponder. This was presumably for the purpose of evading detection and interception by U.S. air defense systems. However, this view appears to be based only on circumstantial information - the simple loss or change of SSR flight data to Air Traffic Control (ATC) – and seems unsupported by conclusive facts. Following these transponder operation changes, ATC was still able to tag and track the primary radar returns of three flights and estimate their locations, directions, ground speeds, and even altitude changes.

I haven't read it, but since Monaghan is a Truther, Ryan is a Truther, and the JoNES is a Truther magazine, and since a 9/11 Truther, by my definition, is a person who is systematically wrong about almost every 9/11-related issue they utter an opinion on, I strongly expect it to be stupid crap. So have at it, beachy, Reheat, and anyone else interested in the air traffic issues.

EDIT: Nevermind. No edit.

 

[DGM]

Reading the article my question would be, So what?

The article assumes there would be an immediate need for ATC to track the plane. This would not be the case because it was still assumed the planes were under control of a responsible pilot. ATC would contact the flight and try to correct the situation all the while assuming the pilot was still going to fly his/her assigned route.

The article shows a basic lack of understanding of procedures using 20/20 hindsight to show what he thinks controllers should have done.

 

[Reheat]

First of all, his basic premise is wrong. What other reason other than the hijackers turning off the transponder could there possibly be for the disappearance of their SSR info? Electrical failure is pretty remote and the most logical reason is that the hijackers wanted to make the airplanes more difficult to see and track. He continues to not understand how SSR works. ATC was NOT able to determine altitude and ground speed with the transponder off. This is plainly proven by controller statements and radio transmissions between the controllers and other aircraft. They had no idea of the altitude and only gross estimates of the speed. True, in some cases they could determine the location via primary radar, but it was somewhat spotty and in the case of AA77 and UA93 they could determine the location at all.

Transponders don't transmit heading information as he indicates. Yes, a track can be determined after the aircraft moves, but there is no heading displayed as he infers.

AA77 was a special case in that the transponder was turned off in an area which did not have primary radar coverage, therefore it was not tracked contemporaneously for that reason. After the fact, it was able to be tracked on the tapes from different radars.

Is he trying to impress someone with his knowledge? If so, it is a utter failure. It's not clear what the purpose of the article is, but whatever it is it's a failure as he gets basic facts wrong.

The whole thing is not even worthy of attention as it's just another "so what" failure by the truther crowd to create doubt or confusion about 9/11 conclusions. Next....

 

[smartcooky]

Transponders don't transmit heading information as he indicates. Yes, a track can be determined after the aircraft moves, but there is no heading displayed as he infers.

This!

The idiot has been watching too much "Air Crash Investigation", and totally misunderstanding the meaning of this type of often seen display...

The ONLY information in this block that is actually sent by the transponder is the altitude (15,100 ft) and the AC ident information (AAL76 = American Airlines Flt 76; the "H" warns ATC the aircraft is a "Heavy", a wide body jet such as a 747 or A340, and therefore capable of generating significant wake turbulence. The "T" on the right tells ATC that the aircraft is equipped with TCAS (Traffic Collision Avoidance System). The transponder also sends "squawk codes" which can tell ATC a number of things about the aircraft, from the fact that it is flying VFR to whether there is an emergency on board.

The "23" is ground speed... 230 knots. This information (as well as any heading information that may appear on other ATC displays), is provided by what is known as "Hit Processing" . The data from PRIMARY radar is fed to a ground station (Radar Signal Processing) where it is analyzed to plot the position of the aircraft on each sweep of the radar beam. After a number of sweeps, as the aircraft moves, the ground speed and track can be determined and continually refined for accuracy. This derived information is then combined with information from the interrogated transponder (the SECONDARY radar) and is fed to ATC and displayed in their screens

Turning off the transponder only makes the altitude and A/C ident disappear, but the Primary radar can still track it and still determine the ground track and ground speed.

 

[Oystein]

Thanks guys!

I, too, wondered what this "paper" is all about, as I couldn't discern an interesting purpose or hypothesis from the abstract.
Good to see that Monaghan delivers according to expectation.

 

[BasqueArch]

As is always the case when Falsers assert inside job fabrications, they reveal not what they know, but provide permanent confirmation of how much they don’t know; or choose not to know. Always.

 

[beachnut]

Another 9/11 truth paper which offers nothing of value. The conclusion ignores evidence, and does not make sense.

The transponders don't have much of a factor on 9/11. We have terrorists first flight, and appears they had no SIOP for use of transponders.

Thanks guys!

I, too, wondered what this "paper" is all about, as I couldn't discern an interesting purpose or hypothesis from the abstract.
Good to see that Monaghan delivers according to expectation.

I agree, I can't figure out what the purpose was.

Maybe Monaghan paranoid mind was trying to say the transponders were jammed for some reason, as he includes transponders dropping off in France... I was thinking about checking the France stuff, but since 19 terrorists did 9/11 and there was no standardization in transponder use after hijackers took over, it does not mean much more that some facts about what was discovered.

Maybe a 9/11 truth follower can explain, or add their 24 bits worth, to a possible paranoid plot implied by the transponder paper.

 

[smartcooky]

Maybe Monaghan paranoid mind was trying to say the transponders were jammed for some reason

Well, jamming transponders isn't really possible unless the jammer is on the aircraft carrying the transponder being jammed. While the transponder transmission is omni-directional, the receiver is directional; the SSR antenna is mounted on top of the Primary Radar antenna and rotates with it.

For a jammer to work, it would have to constantly move to remain somewhere near line of sight between the aircraft and the antenna. Four airliners would require four continually moving jamming transmitters. This is not practical in any real sense.

 

[LSSBB]

Well, jamming transponders isn't really possible unless the jammer is on the aircraft carrying the transponder being jammed. While the transponder transmission is omni-directional, the receiver is directional; the SSR antenna is mounted on top of the Primary Radar antenna and rotates with it.

[qimg]https://www.dropbox.com/s/1wbpaad03qec8j5/PR-SSR.jpg?dl=1[/qimg]

For a jammer to work, it would have to constantly move to remain somewhere near line of sight between the aircraft and the antenna. Four airliners would require four continually moving jamming transmitters. This is not practical in any real sense.

Yaay, learned something new. Thanks, smartcooky.

 

[cjnewson88]

AA77 was a special case in that the transponder was turned off in an area which did not have primary radar coverage, therefore it was not tracked contemporaneously for that reason.

Well, it did but that's a different story..

 

[Reheat]

Well, it did but that's a different story..

Yes, I know. I gave the simple explanation. It's a bit complicated to go thru the technical details of the actual issues involved.