EasyJet 737 incident debunks Pilot for 9/11 truth V-G diagram video

It should also be noted that the copy of the report I link to is authored by one member of the board who balked at blaming crew mismanagement of their aircraft. In his opinion, not enough direct evidence to conclude that.
 
It should also be noted that the copy of the report I link to is authored by one member of the board who balked at blaming crew mismanagement of their aircraft. In his opinion, not enough direct evidence to conclude that.

Yes. However, if you are referring to TWA 841? I have a pretty good grasp of what was "suspected", despite the crew's protestations. Based on what I know from experience with the B727 and the various systems designs, and having flown it. And many, many discussions with others over these many years. (Although of course, I never attempted what is "suspected" to have occurred!!)

But, this is not the place for those details and suppositions.

ETA: (In fact, I've posted before on this, and now realize that, due to memory...and since I last flew the airplane a LONG time ago...I actually got a few details RE: the Leading Edge Devices, and exactly what is actuated at the Trailing Edge Flap setting of "1". Sorry for the mistake).
 
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Well, true to form and to my prediction in post 275 here, SpaceCowboy, aka Rob Balsamo, commttied suicide by mod once again rather than specifically address the issues noted in this and the other, similar, thread.
 
Yes, Rob refused to explain his objection, instead preferring to drop random hints, and go on about how unqualified everyone here was.

I gave him multiple opportunities, however he just responded with more of the same.

https://www.metabunk.org/threads/spacecowboy-rob-balsamos-9-11-ad-hom-and-off-topic-posts.3399/

The ban will be lifted if he emails me a clear explanation of what he thinks is wrong in the Flutter OP. Specifically why he think's there is not a 20% mandated safety margin above Vd at sea level.
 
The ban will be lifted if he emails me a clear explanation of what he thinks is wrong in the Flutter OP. Specifically why he think's there is not a 20% mandated safety margin above Vd at sea level.

I think that this is a very reasonable stance, and request. Facts, not obfuscations, make for better understanding.
 
One that the regulations state that the aircraft will be free of flutter through to 20% greater than Vd for constant mach number and altitude.
It seems that SpaceC is objecting that this is to apply for the condition that the aircraft be in level flight and maintaining a constant Mach number, and that the descent of flight 175 and the manouvering of flight 175 negates the effect of the 20% margin contained in the regulations.
I say that "it seems" to be his objection because he has not actually stated it. Instead he has simply repeated the phrase "constant Mach number and constant altitude"
.
Perusing PfT forums I found one example of one of his adherents asking essentially the same thing. The reply to that post, " what do you think?"

OTOH there are things that Rob Balsamo has stated there that would have at least partially addressed the questions posed here.
One then wonders why he would not reiterate those points here when asked.
- knows the argument is weak?
- sees posting on other forums as "playtime", or at least pretends that's how he views it. So posting isn't really important to him, that would also indicate that seeking to widen his audience and get the message out is also not important.
- the important thing is to garne greater traffic on his site. Posting his argument on other sites is counter productive to that. Better to make a claim then call for debate to move to his site, or cajole others to seek info on his site.
 
Wrt TWA841, PfT had an inquiry concerning this flight. It was shown that the aircraft was at 450+ knots at 5000 feet when it pulled out of the dive, incidentally pulling 6 g in the process.

The response from Balsamo
Yes, and that airplane lost control and needed the landing gear extended to regain control, and it suffered structural failure (pieces of the aircraft broke off). Did that happen with the aircraft on 9/11? Did they lose control and have to extend their landing gear to regain control? No....

The 727 is also a much faster airplane than the 767. I'd post a Vmo/Mmo comparison, but you still don't even know what each mean.

First of all the aircraft was out of control due to a wildly nonstandard slat configuration, it was not a consequence of the high speed.
Much of the structural failure was due to this nonstandard slat extension and the extending of gear at high speed.
This aircraft also rolled through 360 degrees, twice, and experienced g forces that had passengers and crew coming close to blacking out, 6.0 g.

What I find for a 727 is a Vmo of 390 knots/Mmo 0.88M

Max Mach number experienced was 0.96M at 31800 feet a few seconds after the rolling dive began. Here it was certainly not at constant Mach number nor constant altitude while hitting Mmo+0.08 and still 20-30 seconds from having the errant slat tear off.
 
First of all the aircraft was out of control due to a wildly nonstandard slat configuration, it was not a consequence of the high speed.
Much of the structural failure was due to this nonstandard slat extension and the extending of gear at high speed.

Yes.

It is the common tactic of 'PfT' to flat-out lie and misrepresent in order to shoehorn their illogical (and incorrect, unsupported) conclusions regarding the airplanes involved on 9/11.
 
Yes.

It is the common tactic of 'PfT' to flat-out lie and misrepresent in order to shoehorn their illogical (and incorrect, unsupported) conclusions regarding the airplanes involved on 9/11.
i actually don't think he's lying. He's pretty consistent. I think its a fundamental misunderstanding of the terminology.

for ex: (bad ex cause this is an easy one, unlike vg diagrams/regs) the radius thing. if you and I are arguing about pollutants from coal burning plants and I'm arguing under the premise that radius is the entire area and you are arguing from the premise that radius is half, so the area is TWICE as large.. until I comprehend the original misunderstanding in my thinking, we will continue to argue and I will continue to think I'm right and I will base all my new arguments on my false understanding.

and the whole time you will be trying to figure out what the heck im talking about and the whole time i'll be wondering why youre so thick. ; )

I think that sort of thing is what is happening here.
 
I'm arguing under the premise that radius is the entire area and you are arguing from the premise that radius is half, so the area is TWICE as large.. .

It's actually four times as large :) But yes, sometimes what seem like lies can just be a failure to communicate. Especially if clear communication is not a priority.
 
It's actually four times as large :) But yes, sometimes what seem like lies can just be a failure to communicate. Especially if clear communication is not a priority.
Which is certainly part of the problem wrt the thread topic and the one respondent. The available evidence indicates that clear communication was specifically and deliberately being eschewed by one poster.

Concerning the radius example, a personal experience.
I had read an article in which the author stated that the outer edge of a satellite receive dish was responsible for more antenna gain than the inner part of the dish. I did not think about that too much as this article was on the importance of maintaining a parabolic curve to the dish.
I related this to a coworker who scoffed at the notion.
Its true though. Take a ten foot diameter TVRO dish. The inner one foot radius circle (ignoring the third dimension of depth) has an area of π square feet.
The outer one foot of this dish circle though would have an area of
25π - 16π=9π square feet .
Dish signal gain is partly a function of dish area.
 
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from "Yost" on P4T.

Ahem, Jaydeehess basically uses some metaphor here and expects us to believe that a rope is comparable to an aircraft. Ok

He also thinks that speed increases the loading which produces a damping effect on the flutter of the aircraft. So this is why it can survive.

He is evidently not aware of the dangers of thicker air at sea level, flying in a dive over VD at sea level is like gradually crashing into a brick wall due to the increasing density of the air.

In fact, VD is established mainly due to varying air resistance at different altitudes.

Incorrect: VD is a speed selected by regulatory requirements to provide a safe buffer for recovery from an "Upset". Nothing more, nothing less.

Does he even know what VD means? It's like he is denying that it means "Vertical Dive Speed"

Incorrect: Vd is the "Design Dive Speed".

Beyond VD is the structural failure zone, meaning that if you go over VD at certain altitudes the aircraft will experience flutter and then structural failure, the only margin for this speed only applies in "level flight".

Incorrect: The Structural failure zone is not specified in any regulation or regulatory compliant V-N diagram for any aircraft.

VD for a 767 is 420 KCAS [from sea level] to 17,854 ft/.91M above 23,000 ft

Incorrect: VD for a 767 is 420 KEAS which automatically accounts for altitude changes up to the altitude that Md becomes more appropriate.

Again, these speeds are established due to the effects of air resistance at different altitudes

Incorrect: the criteria for establishing Vd is in the appropriate regulation. Namely a fixed relationship to Vc- max cruise speed.

He then goes on to say that manuvering while over VD is good for the aircraft because certain parts of it will move out of the destructive conditions.

I cannot find any such assertion. Maybe you can

Jaydeehess, it does not matter whether it is banking at say 45 degrees or not, it is still in a dive and over VD.

In fact, quickly manuvering while over VD is harmful to the aircraft because it is a sharp change in the G-Loads.

A transport category aircraft has AT LEAST 2.5 positive G and 0 G protection AT Vd. Check the VN diagram, (not Balsamos one because that is not for a transport category aircraft, another reason why it has no place as any sort of evidence.) Test pilots are required to make certain "pulse" control inputs AT Vd specifically to clear the flight envelope to this speed.

This is all irrelevant anyway, because in order to be in a dive the nose has to be pointing down along with the wings, therefore the only way to get out of the VD range (and avoid structural failure) would be to pull up, of course UA 175 did not do that and continued in its dive for over 2 minutes.

The aircraft was doing well over Vd when it struck the WTC. It had in fact pulled up.

In his next post he rehashes that misinterpreted regulation, which still only applies in level flight.

Reduced: 43% of original size [ 1843 x 685 ] - Click to view full image


The airbus test was done in a dive, in fact the aircraft experienced structural failure even before it reached VD, quite crippling to your claims.

Having a part come off in flight is NOT structural failure of the aircraft for flight test purposes. I have had reversers and gear doors come off my aircraft at speeds well below Vd and the appropriate limit speeds of those components. We landed safely.

And no Mick, the claim has not been debunked, the safety margin you cited only applies in level flight, so please explain to me how a plane can be diving and be level at the same time.

And how shallow is this dive in flutter testing?

Reduced: 43% of original size [ 1839 x 373 ] - Click to view full image


Seriously, again, you are implying that an aircraft can be in a vertical dive (increasing mach, decreasing altitude) and be in level flight at the same time?

To claim that VD speeds are based on constants would negate what VD is
.

You have already shown you do not understand what Vd is when you call it a Calibrated Air speed. Vd IS a constant. It is an EAS which takes into account changes in airspeed and altitude.
I am not sure if this is the intent of the constant altitude and airspeed criteria, but if you dive an aircraft to VD, using a KEAS airspeed indicator, and you maintain a constant EAS, then that is in effect what you have just achieved.

A complete oxymoron

If any of you are reading this right now, which I know you will be doing(because you just cross-posted from this thread) , know that I will not respond to any of you if you intend to respond to this post on Metabunk.

Now it would be obviously hypocritical to claim that I am a coward for not coming to debate you over there, because the fact is you have been invited several times to come here and yet you have declined continuously.

So come over here and state your claims

No thanks, Id rather keep it here where P4T's patented argument style.. ad hominem attacks, evasion and strawmen can be neutered.
 
I always assumed the "V" in Vd, Vmo, Vc, etc stood for "velocity" now Pilot's for 911 Truth poster, " Yost, informs us that it stands for "vertical". Now that is confusing isnt it? Vertical Cruise speed, Vertical Max Operating speed??

Hmmm, then there's V1 and V2...............

There is a contradiction in saying that the regulation establishing Vd is for level flight only while telling us it is the vertical and dive speed limit. The former (vertical) being wrong and the later (dive) indicating the condition in which that speed would be acheived.

Yost also seems to be one of those persons on which analogies get completely lost.

Oh, my, now many of us will lose sleep over the lack of response to this thread by Pilots For 911 Truth.
 
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Having a part come off in flight is NOT structural failure of the aircraft for flight test purposes. I have had reversers and gear doors come off my aircraft at speeds well below Vd and the appropriate limit speeds of those components. We landed safely.

Then there is that niggling detail that the Airbus underwent a modification that solved that problem. Yes the aircraft could not be certified as it was designed such that this panel came off in test, THAT IS WHY it was modified and all production aircraft will go out with that modification.
 
I always assumed the "V" in Vd, Vmo, Vc, etc stood for "velocity" now Rob Balsamo informs us that it stands for "vertical". Now that is confusing isnt it?
Seriously? So what's V1 and V2 if it's not level? Does it mean all airstrips have to be downhill?
 
I always assumed the "V" in Vd, Vmo, Vc, etc stood for "velocity" now Rob Balsamo informs us that it stands for "vertical".

No, I believe that TWCobra was referring to a poster at PfT named "Yost". This is (very likely) the same person who posted here on MB as "Blindidiots", and is not Rob Balsamo.

My opinion is, a Rob Balsamo acolyte who is at the student pilot level. He/she can still be saved with actual facts and knowledge, once out from under the influence of woo being spread by the PfT website.
 
No, I believe that TWCobra was referring to a poster at PfT named "Yost". This is (very likely) the same person who posted here on MB as "Blindidiots", and is not Rob Balsamo.

My opinion is, a Rob Balsamo acolyte who is at the student pilot level. He/she can still be saved with actual facts and knowledge, once out from under the influence of woo being spread by the PfT website.
Yes, I noticed my error there and had changed parts of my post to reflect that it was Yost. Missed the first instance of it though.

Edited to correct the error.
 
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Yost either missed my post #291 ( this thread) or had no comment.

It seems "Yost" doesn't want to come back? Wonder if his mistake (i.e., Vd​ meaning "Vertical dive" was noticed at PfT?

Hardly seems fair for the person to have a mistaken belief in the terminology.
 
It seems "Yost" doesn't want to come back? Wonder if his mistake (i.e., Vd​ meaning "Vertical dive" was noticed at PfT?
It would be hard to miss by anyone reading and not simply skimming through it.( my first knowledge of it was TWC's post above).

Hardly seems fair for the person to have a mistaken belief in the terminology.
It would be "fair" to allow Mr. Balsamo to correct him.
Possibly would have been the polite thing to do.
Oh, well!:cool:
 
Clearly you have not ...
This is from page 151 of the Illustrated Guide To Aerodynamics....



Who is going to correct the Illustrated Guide To Aerodynamics which is used in virtually every Aerodynamics course in every aviation college on this planet? [...]
Me. ..., using Fig 5-27 to fake a heavy jet Vg diagram, most anti-intellectual.
What does the Illustrated Guide To Aerodynamics say about the fake Vg diagram pilots for truth use spread nonsense about 911?
That is Fig 5-27, a Vn diagram.
"Figure 5-27 shows a typical V-n diagram for a light airplane." (Illustrated Guide To Aerodynamics p150)

Balsamo take a training diagram to fake Vg diagram for a 767. And the V-n diagram used is for a light aircraft. Now that sums up the expertise for the silly claims pilots for truth make. The Vg diagram by Balsamo is debunked by Balsamo.
 
Balsamo take a training diagram to fake Vg diagram for a 767. And the V-n diagram used is for a light aircraft. Now that sums up the expertise for the silly claims pilots for truth make. The Vg diagram by Balsamo is debunked by Balsamo.

I would only "hope" that this thread has already been linked to, on the "PfT" site, and that the discussion will attract attention, from there....so that the few left who have not yet seen through the "bunk" of PfT will get a chance...to see it.

ETA...I truly do also hope that some from PfT get a chance to see some more realistic aspects to this discussion. Made by many with (perhaps) more relevant experience on the topic.
 
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I would only "hope" that this thread has already been linked to, on the "PfT" site, and that the discussion will attract attention, from there....so that the few left who have not yet seen through the "bunk" of PfT will get a chance...to see it.

ETA...I truly do also hope that some from PfT get a chance to see some more realistic aspects to this discussion. Made by many with (perhaps) more relevant experience on the topic.
Balsamo photo shopped the V-n diagram to take out the speeds. It fooled Yost and other non-pilots.

Vd for the diagram photo shopped is 200 knots. See the line added to cover up the empty spot? Va is 117 knots, and below the Va over the tick mark would be 120 below the line.

The book says, "It is referred to as the maximum dive speed, or Vd."

Still on page 151... "At load factors higher than +3.8 or -1.52, or at speeds faster than 200 knots, structural failure could occur." Oh man, "could", not will, but could occur. Now what will pilots for truth do with a prop plane V-n diagram used to fake a heavy jet Vg diagram. (Illustrated Guide To Aerodynamics, 2nd Edition, H. C. "Skip" Smith, 1992) Balsamo got the page number right, but failed to explain why he photo shopped off the numbers.

It is always the same when researching 911 truth claims, they are all false. You hear things like Flt 77 did some fantastic maneuver turn - and when you get the data, you find a sloppy less than standard rate turn with terrible airspeed control. Same with Balsamo, you research his Vg diagram to find photo shopped speeds. I worked at Wright Labs (think they have a new name now) and went to grad school with leaders in the field of Stochastic Estimation and Control and Aeronautical Engineering. My Aero teacher could study orbital data and predict a new moon on Jupiter, or was it Saturn - it hurts my head to see so much ignorance and nonsense, as 911 truth fakes an aeronautical engineering chart by photo shopping it and making up lies, and then quoting journalist to invent new definitions for Vd.
 
Balsamo photo shopped .... take out the speeds. It fooled Yost and other non-pilots.

Yes indeed. Well aware of this fact.

You hear things like Flt 77 did some fantastic maneuver turn - and when you get the data, you find a sloppy less than standard rate turn with terrible airspeed control.

Also, agreed.

I have posted the proper FDR animation, per the NTSB read of that device...elsewhere. I have watched it countless times. I have also compared it to other NTSB records, which I've also already posted. They all match.

Seems only the "audience" at PfT are ill-informed.

I'd invite all of them to take some time to get away from mis-information.....

ETA....such as PfT's nonsense about the IRS position info, and most importanly...the
"Flight Deck Door" SNAFU:

http://www.911myths.com/index.php/The_Cockpit_Door

(Summary: The claim is....the FDR ....which, oddly the "PfT" claims is FALSE...but, per the FDR, the PfT once claimed that the Flight Deck Door on AA77 was "never opened". (PER the FDR!!!)

(Of course, it is simple.....that aspect was NOT a parameter to be considered important to add to the FDR, by AAL, when they BOUGHT the airplane!!)

This is just ONE example of many, many 'PfT' mistakes, over the last decade...(or so)...


AND....to compound the mistake?? This MIS-information is STILL easily Googled....how sad.
 
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Just revisiting this one for a bit. Robert Balsamo and Yost of P4T were claiming that the 15% (or 20% depending on the time of certification) envelope extension did not apply in a dive due to the phrase "equivalent airspeed at both constant Mach number and constant altitude" in the regulation supposedly negating that.

I have clarified this with my test pilot colleagues; the P4T interpretation is incorrect and if you read the regs it makes perfect sense.

The correct interpretation: In a flight test program, the flight envelope is expanded using test points that require both criteria but not at the same time. A test pilot will fly a constant EAS as he/she climbs OR a profile that maintains a constant altitude as the EAS increases. In this way both the altitude and EAS portions of the flight envelope are cleared.

I hope this clears up the misunderstanding of P4T.


Sec. 25.629 - Aeroelastic stability requirements.
Content from External Source

(a) General. The aeroelastic stability evaluations required under this section include flutter, divergence, control reversal and any undue loss of stability and control as a result of structural deformation. The aeroelastic evaluation must include whirl modes associated with any propeller or rotating device that contributes significant dynamic forces. Compliance with this section must be shown by analyses, wind tunnel tests, ground vibration tests, flight tests, or other means found necessary by the Administrator.

(b) Aeroelastic stability envelopes. The airplane must be designed to be free from aeroelastic instability for all configurations and design conditions within the aeroelastic stability envelopes as follows:

(1) For normal conditions without failures, malfunctions, or adverse conditions, all combinations of altitudes and speeds encompassed by the VD/MD versus altitude envelope enlarged at all points by an increase of 15 percent in equivalent airspeed at
Content from External Source
both constant Mach number and constant altitude. In addition, a proper margin of stability must exist at all speeds up to VD/MD and, there must be no large and rapid reduction in stability as VD/MD is approached. The enlarged envelope may be limited to Mach 1.0 when MD is less than 1.0 at all design altitudes
Content from External Source
 
I have clarified this with my test pilot colleagues; the P4T interpretation is incorrect...

It is gratifying indeed that you have had the contact and obtained the information from those who were actually test pilots, and thus much more knowledgeable than a mere "airline pilot" with experience in the B767, like myself.

I say that with respect, although re-reading it may seem flippant. Not my intent. Those aviators whose job it is to flight-test push boundaries.

A line-pilot then follows the procedures, the 'SOP's that are adopted as a result of the work performed by those other professionals.
 
What this means of course is that UA 175 was flying at or below the certified limit for flutter for a 767 until moments before impact. The video that P4T has put out is based on erroneous information and should be treated that way.

The certified critical flutter speed was 504 KEAS (VD+20%) at a maximum of 2.5 G. This translates to a TAS of 510 knots at 1000 feet, which converts to about 5 knots below the final recorded ground speed.

Undoubtedly the aircraft was on the verge of suffering catastrophic damage due to flutter at this point, the evidence of this can be seen from the serrated condensation trail from the left wingtip/aileron, visible in this video at 0.14. However the evidence shows that destruction from aeroelastic flutter, during the entire approach sans the last few seconds where collision was inevitable, is not possible.

 
What this means of course is that UA 175 was flying at or below the certified limit for flutter for a 767 until moments before impact. The video that P4T has put out is based on erroneous information and should be treated that way.

AGREED wholeheartedly.

The 'P4T' video(s) have continued to provide much erroneous information. For several years.

Perhaps is time to correct (read as "debunk") all of those false claims? Or, has 'P4T' already stumbled and erred, and thus refuted themselves too many times, so as to become exceedingly irrelevant, today?
 
There was a point raised here by I think Mick that structural failure is not necessarily caused by speed or acceleration but extreme maneuvers as well. P4T graphs imply that all the incidences they give of structural failure were caused by the speed. They build on this assumption to suggest that failure can occur even BEFORE Vd.

While there are examples of structural integrity maintained well above Vd, I doubt there is any evidence of structural failure below Vd solely due to speed. This is what P4T should have focused on instead of cleverly insinuating that structural failures can only be caused by speed
 
I doubt there is any evidence of structural failure below Vd solely due to speed

Yes, since Vd marks the cleared part of the envelope, something would have to be very wrong for that to happen. These airliners are very strong. On day one of my initial 747 course I was shown the wing test video where the wings were bent 32 feet upwards before they broke. It made a great impression on me and solidified my confidence in the strength of the airframe.

Below is the B777 test where the wing failed at 154% of the design limit load. Given that the top right of the envelope is VD AT 2.5 G I am guessing that this was equivalent to pulling almost 3.8 G at maximum weight at VD.

It is a nonsense to suggest that Vd marks the structural failure zone at 1G. Balsamo needs to talk with real test pilots like I have and amend his videos accordingly.

 
Yes, since Vd marks the cleared part of the envelope, something would have to be very wrong for that to happen. These airliners are very strong. On day one of my initial 747 course I was shown the wing test video where the wings were bent 32 feet upwards before they broke. It made a great impression on me and solidified my confidence in the strength of the airframe.

Below is the B777 test where the wing failed at 154% of the design limit load. Given that the top right of the envelope is VD AT 2.5 G I am guessing that this was equivalent to pulling almost 3.8 G at maximum weight at VD.

It is a nonsense to suggest that Vd marks the structural failure zone at 1G. Balsamo needs to talk with real test pilots like I have and amend his videos accordingly.


Wow! That is impressive and I hope to never , ever, see the wing of a plane I am in anywhere near that distorted. For obvious reasons.
 
W

Undoubtedly the aircraft was on the verge of suffering catastrophic damage due to flutter at this point, the evidence of this can be seen from the serrated condensation trail from the left wingtip/aileron, visible in this video at 0.14. However the evidence shows that destruction from aeroelastic flutter, during the entire approach sans the last few seconds where collision was inevitable, is not possible.


But, but, but, according to Rob Balsamo, a pilot he trains would never, ever, deliberately exceed published acceptable airspeed or loading. Must be a form of hypnosis that he uses to ensure that even a suicidal pilot cannot bring himself to do any wrong to the aircraft.
 
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