Debunked: Pilots for 9/11 truth WTC speeds

I doubt the 757 in that video was exceeding VMO. The RNZAF operates it to airliner standards.

Ah....burst the bubble, why dontcha? (**)

**(JK)

I suppose though...that video is a great demonstration of how kinetic energy (AKA, airspeed to apply to an airplane's potential) can be translated into altitude gain....for a brief amount of time, and counter to the effects of gravity.

Therefore, it is reasonable for people to realize the opposite effect (in the sense that gravity is a contribution, whether as a force to slow you down when ascending, or speed you up when descending) that gravity can have on an airplane.
 
I am just trying to understand pilot for 9/11 truth claims. The video that says "pilots say no way" the phone calls to Aeronautical engineers is my biggest question when they say that the engine can't do that. I've seen a couple more videos where they actually talk to Boeing and she laughs and say no as well.
She was not an engineer, and she mostly likely laughed because the FAA speed limit is 250 KIAS below 10,000 feet - she had no clue what the top speed theoretically is for a 767, she answers the phone - she has to be told by "Boeing".
The one engineer on the video had to think, and he is making up his mind in seconds, instead of doing the math - thus he is falling back on BS opinion, and not reality.
The fact is Flight 77 engines were approaching the temperature limit at 483.5 knots at impact.
On the other side, at sea level a jet engines has it RATED thrust, thus comparing a jet able to cruise in thin air with much reduced thrust is silly. I flew a jet with poor thrust for what I was carrying, my critical field length was 12,000 feet sometimes; we would have to burn off fuel to takeoff legally for safety of flight, and for war time, our critical field length was off the runway, we could not loose but a fraction of thrust and make it off the ground.
Jet engine produce the most thrust at sea level, you have to run the numbers to see where drag would equal thrust.

All the jets on 911 were in decent up to impact - and even if you want to say they leveled off, the excess speed takes time to bleed off unless you climb.

As I said before you can glide at 300 knots in a Boeing jet with 3 degrees down, like going down hill you can exceed the speed limit coasting.

The best way to understand pilots for truth claims, they are all BS. Pilots for truth quote mine anyone and then turn that into some piece of "evidence" for their claims. The video is a perfect example of asking question cold, and then quote mining the results - instead of doing any math, we have opinions pilots for truth can use to mislead and act like "experts".

Where is the math for the video, the proof, the aerodynamic proof? Where is it? When I did aero for my masters degree we filled the board with equations, pilots for truth fill the "board" with BS opinions. You got opinions from engineers and each one was wrong. Why are they wrong? Because on 911 Flight 175 was "seen" on RADAR going 590 mph, nearly 510 knots (in pilot training, in T-38 we could over 600 knots at near sea level, trying to beat thunderstorms back to the base, in our min fuel white rocket).
Flight 77 FDR show 77 was going 483.5 knots, 504 knots would be 1.2Vd.
Each of the experts who talked off the top of their heads was wrong, proved wrong by RADAR, and FDR.

Video is debunked by reality. Now did flight 175 suffer any damage, who knows, parts were all over from the impact, no major damage was seen on the low resolutions slow speed video. When a fellow pilot tried to catch me when I was doing .9 MACH, and Vmo all the way home to base, he did catch me, and lost some skin underneath the leading edge of the wing; the Crew Chief was upset big time. When we refueled the SR-71 we took it to Vmo, and on our airspeed indicator we could be above the Vmo indicator - only once did I have flutter at the high speed, an aileron was vibrating - the jets were over 30 years old.
 
That is a video I have referred to often, over the years, as it soundly (pun) refutes so many claims by the 9/11 "truth movement". I cannot recall a single instance, however, when the owner of P4T ever addressed it. Might have happened, and I missed it.

Unable to verify the actual "500 knots" value of that B757. It was operating at an airshow, and despite being a military-use airplane, is basically "off-the-shelf" as a B757. The B767 shares a commonality, so much so that for pilots it is a "common" type-rating. Minor differences, easy to learn. The B767 engines have more powerful thrust "numbers", though.

Back to "500 knots" in that example? I am certain it was beyond the VMo of 350 knots, but not certain as to how much.(350K for the B757, 360K for the B767....but, keep in mind, that the limit RE: IAS...the "Barber Pole" varies by altitude. But, we can presume this demonstration was well below 20,000 feet MSL!!).

Still, it is a very strong example of the robust nature of the Boeing airliner product (oh, and I'll toss a bone to Airbus too...they are built to the same certification requirements, in terms of airframe structural integrity).

The RNZAF Pilot, Tony Davies, has given an account of the display.


I was the captain of that particular shot, filmed during a Squadron open-day a couple of years ago. It's part of a routine that has been performed over thirty times at various airshows and practices around the world including RIAT Fairford 2003, Kemble 2006, RAF Waddington 2006, Warbirds Over Wanaka 2004, Avalon 2005.

The low pass is flown into wind at 350 knots (indicated) and 100 feet above the runway. It's a 2g pull up to between 45 and 55 degrees nose up pitch (although there has been higher) and the zoom climb ends at an altitude between 8000 and 10000 feet depending on the type of pull up used. The sequence does not end with a loop as some of the readers speculate, but in fact with a 60 degree wingover at around 220 knots. It is easily possible to enhance this maneouver with a steeper climb and bank but there is no need - it is spectacular already, and safe.

The aircraft is NZ7572 (formerly PH-TKB of Transavia) and it's sister ship, NZ7571, is seen in the foreground of the video shot. Both aircraft are operated by 40 Squadron at Royal New Zealand Air Force Base Whenuapai in Auckland, New Zealand. It is a B757-2k2 with RB211-E4 engines, shortly to become E4Bs.

Feel free to post this information if you so desire. If you want more details, I can provide. I can also pass you more videos of other maneovers we have done but I am a little busy right now and need some time to convert them to MPEG. I have attached a shot of the same aircraft involved with a formation practice for a London flyover with 3 Typhoons taken in November this year, as well as a quick shot taken from inside the B757 at the same time.

Regards,
Tony Davies.
Content from External Source
http://www.airliners.net/aviation-forums/general_aviation/read.main/3157106/

Crank up the volume at 2:12

 
The best way to understand pilots for truth claims, they are all BS. Pilots for truth quote mine anyone and then turn that into some piece of "evidence" for their claims. The video is a perfect example of asking question cold, and then quote mining the results - instead of doing any math, we have opinions pilots for truth can use to mislead and act like "experts".

BINGO!!! I just wanted to pull that out of the text, for emphasis. Because it is (again), spot on.
 
Why do you say this????
I think WW is implying that P4T have a tendency towards deleting posts and banning users that ask questions that may expose the shortcomings of their arguments.

He wasn't referring to Metabunk, here folks are only likely to get banned if they veer too far from the politeness policy or posting guidelines too often.
 
I think WW is implying that P4T have a tendency towards deleting posts and banning users that ask questions that may expose the shortcomings of their arguments.

Yes, thank you "jonnyH". That perfectly describes what I implied. An attempt to express an opinion, without seeming too accusatory nor impolite.
 
I get where this is coming from now.

P4T are desperate to prove EA990 broke up well below the Vd + 90 speed of UA175.

One if their forum members posted

This

on Reddit, which explains that since an EAS of 510 knots at sea level equates to M 1.18 or 722 knots at 22000 feet, then the speeds are impossible.

This is easy to debunk when you point out the errors and omissions.

What NAM007 has forgotten is
that flying at Mach 1.18 at ANY altitude in a 767 is above the aeroelastic limit. So the quoted EAS at that altitude becomes moot as destructive flutter would have been encountered well before that speed at 22000 feet.

Not so however when flying at sea level where the aircraft was well below it's designed flutter limit.

The 722 knots he quotes is also TAS. It is meaningless in the context of the claim. The aircraft would never get near this value, nor is TAS used as a limit airspeed.

What NAM007 has done is to plug in an EAS that UA175 was flying at Sea level, and converted it to 22000 feet to arrive at a ludicrous figures and not noticed that another limit would have been reached first. He is correct in one sense; a 767 can't do 510 KEAS at 22000 feet, but he arrived at the wrong reason why.

To illustrate the point, an EAS at the VMO value of 360 knots and the aircrafts ceiling of 43000 feet yields a MN of 1.36.

The first two parameters are inside the flight envelope, but their product isn't due to flutter limits.

If you work out what the EAS of EA990 ACTUALLY WAS, such published in the OP, it was nowhere near the terminal EAS that UA175 survived.
 
I get where this is coming from now.

P4T are desperate to prove EA990 broke up well below the Vd + 90 speed of UA175.

One if their forum members posted

This

on Reddit, which explains that since an EAS of 510 knots at sea level equates to M 1.18 or 722 knots at 22000 feet, then the speeds are impossible.

This is easy to debunk when you point out the errors and omissions.

What NAM007 has forgotten is
that flying at Mach 1.18 at ANY altitude in a 767 is above the aeroelastic limit. So the quoted EAS at that altitude becomes moot as destructive flutter would have been encountered well before that speed at 22000 feet.

Not so however when flying at sea level where the aircraft was well below it's designed flutter limit.

The 722 knots he quotes is also TAS. It is meaningless in the context of the claim. The aircraft would never get near this value, nor is TAS used as a limit airspeed.

What NAM007 has done is to plug in an EAS that UA175 was flying at Sea level, and converted it to 22000 feet to arrive at a ludicrous figures and not noticed that another limit would have been reached first. He is correct in one sense; a 767 can't do 510 KEAS at 22000 feet, but he arrived at the wrong reason why.

To illustrate the point, an EAS at the VMO value of 360 knots and the aircrafts ceiling of 43000 feet yields a MN of 1.36.

The first two parameters are inside the flight envelope, but their product isn't due to flutter limits.

If you work out what the EAS of EA990 ACTUALLY WAS, such published in the OP, it was nowhere near the terminal EAS that UA175 survived.
I have done a lot more research on this and I see the way P4T came up with the excessive mach #. But it's only in certain math but not good math. It fails in the actual aeronautical math, Especially when it comes to the way air reacts when approaching the speed of sound. Thank you for helping me understand their corruptions!! They have some explaining to do!!!!
 
Yes, I see what you mean, but in reality UAL 175 certainly did not fly a vector 90° vertical to the earth's surface, so..although a fun math calculation and hypothetical, it really doesn't apply. I am waiting for an answer about what the definition of an airplane in a "dive" is.

90° is of course the extreme. (And unrealistic, except in Bugs Bunny cartoons).
Yes, but my first calcs were for 5 degree down angle.
One could calculate the acceleration contribution from gravity at any angle but since we are speaking to cobatting drag, which is a force, its better to calculate the force contribution due to gravity at any downslope angle. In such case the mass of the aircraft becomes, of course, significant.

Yes, a 90 degree is unrealistic.
 
The RNZAF Pilot, Tony Davies, has given an account of the display.



The low pass is flown into wind at 350 knots (indicated) and 100 feet above the runway. It's a 2g pull up to between 45 and 55 degrees nose up pitch (although there has been higher) and the zoom climb ends at an altitude between 8000 and 10000 feet depending on the type of pull up used. The sequence does not end with a loop as some of the readers speculate, but in fact with a 60 degree wingover at around 220 knots. It is easily possible to enhance this maneouver with a steeper climb and bank but there is no need - it is spectacular already, and safe.

Content from External Source
2G pullup + cool morning air gets nice vapour effects :)



Photo mine from the RNZAF 75th Anniversary show in 2012. Being an airshow goer in NZ I've seen the 757 display many times, and it never gets old.
 
Ah, OK....again, thanks to you (Mumbles) and to (TWCobra) for the contributions. The RNZAF fly the B757 at "barber pole" (which near Sea Level is 350 knots for that airplane).

Good to know, for comparison purposes.

(ETA): I am including an image of a typical B757/767 Airspeed Indicator, to illustrate. This particular photo was taken at altitude, so the "barber pole" (or, Airspeed Limit Indicator) has moved per commands from the ADC ('Air Data Computer') to reflect current IAS ("Indicated Airspeed") limits for the specific altitude/temperature at present.



You can see via the display clearly the "Mach number" is 0.814, and the IAS is 264 knots.

Note (please) also the white "bugs" (as they're called) on the rim of the A/S Indicator. These are positioned by the pilots as references, primarily when setting up for every take-off, and every landing.
 
Last edited:
I doubt the 757 in that video was exceeding VMO. The RNZAF operates it to airliner standards.

With regards to UA175, the aircraft was in a substantial dive before impact.

I had a couple of VMO exceedences during my time on the aircraft, usually occurring either climbing into a jetstream or descending out of one. The aircraft will exceed VMO easily in those circumstances.

In the days when Australia didn't have a speed limit below 10000 feet, I have vivid memories of entering the circuit at Coolangatta (Gold Coast) at 330 knots plus with idle thrust from a long descent. The aircraft required speed brake to slow down.

The fastest of all the speed analyses from 9/11 puts the aircraft doing around 510 knots at impact, therefore it is up to P4T to prove that isn't possible with a standard jet.

]
So ballpark, it descended about 8000 feet in the last minute. At 500 mph groundspeed that would equate to 44000 feet horizontally. That's about a ten degree down angle of flight. Less than that at a faster groundspeed.
Inversetan(-8000π/44000)
 
Last edited:
The fastest of all the speed analyses from 9/11 puts the aircraft doing around 510 knots at impact, therefore it is up to P4T to prove that isn't possible with a standard jet.
And the Edouardo Kausel (MIT) videos study found 437kts ground speed at impact.
The NTSB speed graph use only one radar (EWR) on the final seconds and some say it is not very precise to calculate high speed (primary radar get only the distance and the azimut)
 
Back
Top