Aircraft Control and Barber Pole

[RalphTheMouth]

Hi All,

I'm doing a little survey.

I was hoping some here could give their honest opinions regarding Vmo/barber pole and the effects of aircraft control. I would rather start a regular poll that most forums have where you just click on a selection, but it doesn't seem I can here at pprune. Without further ado...

Think of the aircraft you operate.

Now think of exceeding Vmo/Barber Pole at any altitude on your ASI.

Now please think, in your expert opinion, when you feel your aircraft will no longer be controllable/survivable above such limits.

If you would be so kind, please copy/paste the following in your reply which applies to you and the aircraft you fly. When replying with your selection, please post the aircraft which you operate.

10-30 knots over Vmo/Barber Pole
30-50 knots over Vmo/Barber Pole
50-70 knots over Vmo/Barber Pole
70-100 knors over Vmo/Barber Pole
100-130 knots over Vmo Barber Pole
130-150 knots "
150-200 knots "
200+ knots "

Thank you in advance for your participation.

[SomeGuyOnTheDeck]

Ok, I'm no pilot. Just occasional self loading freight. All the same, I have to ask. Why do you think anyone's opinion about what the effects of exceeding Vmo are is of interest? Given that it is a limitation derived (hopefully) from an understanding of the airframe limitations, taking into account a safety factor, what useful knowledge could be gained by asking what pilots who presumably don't intentionally exceed the limit think will be the results if they do? If 95% of them were (hypothetically) to say that they would be happy to exceed it by 50 knots, would this justify revising Vmo?

I'd like to think that v-speeds are based on analysis, not on straw polls.

[411A]

when you feel your aircraft will no longer be controllable/survivable above such limits.

I have no first had experience whilst exceeding Vmo, however...I know some of the Lockheed test pilots that did, and they report no particular problems exceeding Vmo by 30 knots and Mmo...to M.98 (Mmo M.90)
Type, Lockheed L1011.

[stilton]

Rather a strange question.




However, one of the 767's that hit the WTC was indicating 460 KIAS




This is 110 knots over VMO.





Of course they were not planning on using the Aircraft again.

[SomeGuyOnTheDeck]

have no first had experience whilst exceeding Vmo, however...I know some of the Lockheed test pilots that did, and they report no particular problems exceeding Vmo by 30 knots and Mmo...to M.98 (Mmo M.90)
Though this may be relevant, I think one needs to be a little wary of the 'I know somebody that got away with it' argument. This is a little prone to what statisticians refer to as 'sampling bias': you aren't likely to have a conversation with somebody who tried it, and killed themself in the process...

[RalphTheMouth]

I'd like to think that v-speeds are based on analysis, not on straw polls.V-speeds are based on analysis. Specifically flight and wind tunnel tests.

With that said, it is always nice to know what actual pilots think their aircraft can perform.

Opinion based on experience counts for something. No?

In other words,

Would you take a corner in a Hyundai at the same max speed you would a Corvette?

How would you know the difference if you never lost control in either?

[411A]

you aren't likely to have a conversation with somebody who tried it
Wrong.
I know many of the guys personally....and they certainly did not get 'killed' in the process.

[RalphTheMouth]

Rather a strange question.
However, one of the 767's that hit the WTC was indicating 460 KIAS

Really?

Which one?

[Capt Claret]

Very strange question, however an answer from 15 years ago.

My initial DH8 (300) endorsement was conducted in the aircraft and fortunately for me, the Training Capt was a Bombardier test pilot.

In conversation one day he mentioned that during the type certification, the aircraft was in a dive at Vmo +, from memory somthing like 270 kias, with a Vmo of 242 (if memory serves), when the gear extended for no apparent reason.

Post flight inspection revealed no damage to gear, gear doors, or airframe despite the airframe being some 30 kts over Vmo, and the gear extending with a greater over-speed.

[RalphTheMouth]

.I know some of the Lockheed test pilots that did, and they report no particular problems exceeding Vmo by 30 knots and Mmo...to M.98 (Mmo M.90)Thanks for your reply 411A.

At what speed do you think they would have reported problems?

Vmo+50? +70? +100?

Do you have a source for the test pilot flight?

[RalphTheMouth]

Very strange question, however an answer from 15 years ago.Thank you for your reply Capt Claret.

So it appears your aircraft underwent un-commanded control at 30 knots over Vmo.

Thanks again for your reply.

[SomeGuyOnTheDeck]

Quote:
you aren't likely to have a conversation with somebody who tried it
Wrong.
I know many of the guys personally....and they certainly did not get 'killed' in the process.

Now that has to be a classic example of a half-quote. I've no reason to doubt that you know people who have exceeded Vmo, and got away with it. How do you think they would have told you about it if they had exceeded Vmo and killed themselves? What part of 'sampling bias' is it you don't understand?

[mig3]

I don't know much about aircraft certification and airframe limits, though I do recall that new airframes are often tested in steep dives in excess of Vmo, to determine the maximum dive speed Vd? If you could find the figures for Vmo and Vd for a given aircraft that would go a ways to answer your question, as obviously the test pilots did not experience any loss of control up to this speed.

[RalphTheMouth]

I don't know much about aircraft certification and airframe limits, though I do recall that new airframes are often tested in steep dives in excess of Vmo, to determine the maximum dive speed Vd? If you could find the figures for Vmo and Vd for a given aircraft that would go a ways to answer your question, as obviously the test pilots did not experience any loss of control up to this speed.

Thank you for your reply mig3.

Yes, I understand.

It is the classic V-G flight envelope.

http://upload.wikimedia.org/wikipedia/en/1/13/PerformanceEnvelope.gif

But what I'm asking here, is the opinions from experts based on experience.

So far we have un-commanded changes to the fundamentals of flight based on Capt Claret, at 30 knots over Vmo.

411A claims L1011 crews experienced no changes at 30 knots over Vmo.

All I am doing here is to find out expert opinion of those who have time in their aircraft and when they THINK (based on their experience in their aircraft), they would lose control over Vmo.

I am in no way asking anyone to try it, or admit they have. Just opinion only.

[411A]

...and got away with it.
"got away with it"...rubbish.
It was part of the flight test program.

Clearly you know nothing about flight test procedures.
Therefore, you will be ignored by those that do.
No surprise.:ugh:

[SomeGuyOnTheDeck]

All I am doing here is to find out expert opinion of those who have time in their aircraft and when they THINK (based on their experience in their aircraft), they would lose control over Vmo.
I'd hope an expert could tell the difference between what they THINK would happen, and what they KNOW, and not give credibility to speculation.

[SomeGuyOnTheDeck]

Quote:
...and got away with it.
"got away with it"...rubbish.
It was part of the flight test program.

Clearly you know nothing about flight test procedures.
Therefore, you will be ignored by those that do.
No surprise.:ugh:
Are you actually capable of comprehending a simple statement? I merely pointed out that knowing people who had done something isn't necessarily proof that it is always safe. Can you please explain the flaw in my reasoning?

[BOAC]

Are you actually capable of comprehending a simple statement? - any questions?

RTM - I don't think I have even entered the '10-30' bracket!

[RalphTheMouth]

I'd hope an expert could tell the difference between what they THINK would happen, and what they KNOW, and not give credibility to speculation

Opinion based on experience is very different than speculation.

Do you disagree?

[rudderrudderrat]

Hi Ralph t.m.

Mad Flt Scientist posted a very comprehensive answer in Dec 2006
here. (http://www.pprune.org/tech-log/254943-demonstrated-design-dive-speed-vdf.html)

Based on his answers - I reckon my A320 would still be controllable at MMO + .07 Mach or VMO + 50 kts. However, I have no intention of deliberately verifying this.

P.S. Before everybody with a copy of A320 FCOM explains how the protection Laws operate - let's assume they were turned off / failed for some reason. (e.g. Frozen pitots)

[John Farley]

Ralph

At face value your first post could indicate that you are serious.

However

You are anonymous.

You give no details of your industry background.

The relationship between Vmo and Vd is a matter of regulation and flight test.

You ask people to give their views based on their experience when by definition they have no experience of what you are asking about.

You give no indication of what you intend to do should anybody respond along the lines you request.

So please don't hold your breath.

JF

[IGh]

There are several mishap/recovery examples recording response during HIGH SPEED dive, available in Accident Rpts, eg:
-- N840TW / 4Apr79,
-- B747SP / N4522V / 19Feb85,
-- A310-308 / 22Mar94 / F-OGQS, “Glinka”.

From flight test reports you can gather various responses during high-speed testing, here's one:

DC8-43 / 21Aug61, RR Conway M512 engines, N9604Z, in Canadian Pacific livery, with Flight Test Instrumentation:

-- climbed to PA = 50,029' at GW =170,600 Lbs; Set-up stab trim for dive (to aid in recovery) so that elevator push force = 50 Lbs (with CG = 27% MAC); set T/O Thrust, pushed nose down to -22 degrees pitch attitude.

-- In dive over Edwards AFB: Max TAS @ 39,614' of 662.5 MPH achieved true Mach = 1.012 at 41,088' (Indicated Mach was .96).

-- Recovery: at 42000' full up elevator yielded no change in G's! and Stabilizer Trim would NOT function. Had to relax elevator, reset trim from 0.5 to 1.5 a.n.u. which resulted in 1.7 G's by 36,000'. Descending through 42000' noted Aileron Buzz of 36 cps, and rudder buzz of 28 cps (disappeared by 36000'); buffet at 35,000' while slowing through M=.94.
[per AAHS Journal Spr '92, by WF Smith]

[411A]

Quote:
Stabilizer Trim would NOT function.

Gosh, I wonder why?
Common, with early design jet transport aircraft, in such extreme situations.
And yes, I know of the pilots that did so, with the DC-8.
707, similar, except...M.96 not exceeded.
IE: with the 707, severe mach tuck would be experienced at mach numbers exceeding M.85.
NOT a pleasant experience...
Mach tuck with the L1011...hardly noticable, due to the superior design.
Burbank got it right with their superb wing design.
L1011, in a class of its own, in aeronautical terms.
IE: the gold standard, to which others hope to attain.


From all reports previously, deHavilland got it right with the DH, (later HS.) 121 Trident.
Trident...a good hi-speed design, from the get-go.
Triplex autoland was superb, as well.:ok:

[Permafrost_ATPL]

Vmo exceeded by 100 kt on a 737-700 during a flight test that went horribly wrong:

http://www.pprune.org/rumours-news/358016-easyjet-b737-pitch-down-incident-12-january.html

Cheers

P

[RalphTheMouth]

Thank you all for your very thoughtful replies.

Just one more question.

Is there anyone here that feels an aircraft will be stable/controllable at 150 knots over the barber pole of that aircraft, at any altitude, and if so, can you please find one that has been positively identified to achieve such excessive speeds over it's barber pole?

(ok, so I guess that was two questions)

Thanks in advance for any input.

[ADDIS77]

Originally posted by John Farley

Ralph

At face value your first post could indicate that you are serious. He's not. RalphTheMouth is a 9/11 Truther.


You are anonymous. Ralph is most likely XXXXX of Pilots for 9/11 Truth.


You give no details of your industry background. King Air pilot and professional 9/11 Truther.



So please don't hold your breath. You see, John, Ralph here believes that Flight 175 (the second plane to hit the towers) would not have been able to achieve it's reported 500 knot impact speed without significant modifications to the airframe and engines. He also believes that there were no hijackers at the controls because it would've been impossible for inexperienced pilots to control the aircraft at 150+ knots over Vmo.

That's right, Ralph believes that Flight 175 was flown into the tower via remote control.


Let's all hope that Ralph holds his breath so that there will be a lot less conspiracy nonsense on this board.

[GR53]

At face value your first post could indicate that you are serious.

However

You are anonymous.

You give no details of your industry background.

The relationship between Vmo and Vd is a matter of regulation and flight test.

You ask people to give their views based on their experience when by definition they have no experience of what you are asking about.

You give no indication of what you intend to do should anybody respond along the lines you request.

So please don't hold your breath.

JFExcellent post, JF, and well said. I'd wager that "Ralph" will not offer up any credentials lest he/she reveal his true identity, as pointed out by ADDIS77. It appears "Ralph" is seeking confirmation from outside his/her own collection of "expert" pilots, which is indeed an infinitesimally small sampling of aviation professionals. He/she will not get the confirmation bias he is looking for here, so will proceed to bad-mouth and denigrate this forum in other locales. Bet on it.

[ADDIS77]

It appears "Ralph" is seeking confirmation from outside his/her own collection of "expert" pilots, which is indeed an infinitesimally small sampling of aviation professionals.


Hi, GR53. It appears that you are familiar with "Ralph's'' claims of "impossible speeds" and that his "expert" pilots could not hit the World Trade Center in a 767 if they had to. I believe some of them even tried to do it in a simulator and claim that they failed. LOL!


Remind me not to fly with that group of incompetents.

[Capt. Inop]

A google search came up with this: 9/11 even real pilots couldn't do it, page 1 (http://www.abovetopsecret.com/forum/thread602869/pg1)

[Checkboard]

Ralph here believes that Flight 175 (the second plane to hit the towers) would not have been able to achieve it's reported 500 knot impact speed without significant modifications to the airframe and engines.
... so an un-named power develops a nefarious plot to fly an airliner into a building, and instead of simply using a normal airframe and 300 odd knots, decides to re-develop the airframe simply in order to achieve a slightly (in terms of damage done) impact speed of 500 knots? :rolleyes:

[ADDIS77]

... so an un-named power develops a nefarious plot to fly an airliner into a building, and instead of simply using a normal airframe and 300 odd knots, decides to re-develop the airframe simply in order to achieve a slightly (in terms of damage done) impact speed of 500 knots? :rolleyes: That's right, Checkboard, the most sinister attack ever pulled off against America was foiled by a bunch of internet pilots because the un-named planners didn't realize said pilots would figure out that it is "impossible" for a 767 to reach 500 knots at 1000 feet MSL.


Don't forget, this group of pilots also believe that the aircraft was remote piloted into the tower.

[CONF iture]

Ralph has a good question.
Would the manufacturers be interested in answering it ... ?
On the Airbus side they really don't want their airplanes to go over VMO. High speed protection would trigger and take control from the pilot at VMO + only 4 knots ... they must have a reason for that ... ?

[Mad (Flt) Scientist]

No OEM wants their aircraft above Vmo. Whether the protection is automatic flight envelope limiting (as described), semi-automatic (most AP systems or At systems wont let you go past Vmo plus "a bit") or manual (various warnings going off when Vmo is exceeded) its always the same - don't go past Vmo.

Why? Because that is the legally certified maximum speed for normal operation. it's the maximum speed where the aircraft has been shown to comply with every single regulation required to be given a type certificate.

What it is emphatically NOT is a deadly cliff edge, past which certain death awaits. in fact, in order to be allowed to publish that Vmo speed, the OEM has done a huge amount of work demonstrating that considerable margins exist at that speed, and has tested the aircraft well in excess of that speed.

To deduce from a speed limit that it must be incredibly dangerous or impossible to go above that speed would be akin to looking at the speed limit on a British motorway, say, at 70mph, and saying "well, obviously they put that limit there because it's certain death to drive at 75mph". Nonsense. It IS more dangerous at 75 than at 70 (and indeed also more dangerous at 70 than at 65 or 60), and the 70 number is to some extent chosen based on an acceptable level of danger, and then used for various design considerations (like the radius of curves in the road, or the strength of the crash barriers, and so on). But until something else goes wrong, people can happily race past at 100mph, with the biggest danger being to their wallets and their driving priviledges.

[Machinbird]

This subject has been discussed before on this forum. See:
http://www.pprune.org/tech-log/282962-vmo-absolute-aerodynamic-limit.html
Vmo/Mmo limits can exist for a variety of reasons. Flutter, Certification limits, Mach Tuck effects, etc. Down low, you can go pretty darn fast without bumping Mach limits. As long as you don't run into a flutter limit or a bird while accelerating, there ought to be enough thrust to get up to at least 500 knots. As long as your controls are still working conventionally, flying into a building shouldn't be hard to do. I've been much faster down low and about the only difference is a much larger turn radius and the greater beating you get from turbulence down low.
If you will remember, both aircraft hit with significant bank angles. This could be the result of an intent to increase multi-floor damage on the part of the bad guys, or simply the result of alignment turns as they got in close.

[GR53]

Don't forget, this group of pilots also believe that the aircraft was remote piloted into the tower.

Which begs the question - if the Pilots who are members of the Pilots for 9/11 Truth Club say it is too difficult/impossible for even THEM to hit the towers in a 767 traveling at 470 knots, why they believe it would be easier for a remote-controlled aircraft to hit the towers, what with the inherent data-link latency and restrictions of that technology in 2001, one can only scratch their head over.

So, they claim these were "beefed-up" aircraft, structurally and engine-wise with remote-controlled capabilities added to the airframe.

Which takes us back to the opening post's question - "Aircraft Control and Barber Pole." If "Ralph", who is most assuredly XXXXXXX, ever comes back, I would like him to answer the question if conventional pilots could not control an aircraft at those speeds, what makes him think a remote-controlled one would, with a modified or-not 767?

Methinks XXXXX won't be back to answer.

[RalphTheMouth]

Is it customary to ALLEGE the identity of posters on PPRUNE?



If so, it appears ADDIS77 (and his sock GR53), both registered Sept 2010, is XXXXXXX, a wannabe "Tom Cruise" obsessed with XXXXXXX. You see, XXXXXXX was so upset he couldn't make it to Top Gun (let alone the front seat), he decided to take it out on others who actually have, such as XXXXXX and XXXXXXXx.

[List of CVs of various folk probably isn't necessary - JT]

People like ADDIS77/XXXXXX feel it is "easy" to control a 767 at Vmo+150, Va+220 --and pull G's-- out of a 10,000+ foot dive, while rolling on G's cranking into a 38 degree bank, to hit a target with less than a 25' margin for error - for a pilot with less experience than one who couldn't control a 172 at 65 knots.

Does anyone here agree with him that such a maneuver is "easy"?

[RalphTheMouth]

Ralph has a good question.
Would the manufacturers be interested in answering it ... ?

Actually, they have.

Question: "So there is no way that a 767 could be going 500 mph at 700 ft altitude?"

Boeing spokeswoman XXXXX replies with laugh, "Not a chance".

Scroll forward to 2:57 as the first call is inaccurate
PKswGf7h5DY

You can see more interviews with United and American Airlines 757/767 Captains, both who have actual command time in the aircraft reportedly used on 9/11, here.

Full Film - 9/11: World Trade Center Attack - Pilots For 9/11 Truth Forum (http://pilotsfor911truth.org/forum/index.php?showtopic=19732)

[CONF iture]

I can see that many estimates on the speed of UA175 have been produced.
Knowing the skyline of NY and the spots from where the few available video were taken, isn't it possible, probably by using goggle earth and some basic trigonometry, to produce one more estimate that could confirm or not what has been published already ?

[RalphTheMouth]

I can see that many estimates on the speed of UA175 have been produced.
Knowing the skyline of NY and the spots from where the few available video were taken, isn't it possible, probably by using goggle earth and some basic trigonometry, to produce one more estimate that could confirm or not what has been published already ?NTSB Video Impact Speed Study (http://911depository.info/PDFs/NTSB%20Reports/Video%20Data%20Impact%20Speed%20Study%20UA175.pdf) (8mb pdf)

Summary
Using distances taken directly from the video screen, flight 175's groundspeed was calculated to be between 473 and 477 Knots just prior to the collision with the building. Using distances taken from video screen prints, groundspeed at impact of 504 Knots and 507 Knots were calculated. This compares to an impact speed of 510 Knots calculated from radar data in the Radar Data Impact Speed Study (AA11 & UA 175)

NTSB Radar Data Impact Speed Study (http://pilotsfor911truth.org/p4t/Radar_Data_Impact_Speed_Study--AA11,_UA175.pdf) (9.15mb pdf)

Keep in mind that the aircraft which impacted the south tower had mostly a headwind on it's path. So KTAS is actually a few knots higher than the groundspeeds reported above.

[john_tullamarine]

Guys - lots of willy waving been going on above. I've deleted a bunch of names as being not overly relevant to Tech Log discussions (if I've missed any please do let me know and I'll have another go).

If the thread doesn't return to a reasonably level-headed discussion I will have to consider removing it to make the problem go away - not something which we do other than very rarely in the forum.

[aerobat77]

Now please think, in your expert opinion, when you feel your aircraft will no longer be controllable/survivable above such limits.

what a question... NO real pilot will intentionally go significant beyond barber pole to test at which speed he looses control and the aircraft seperates. the pilots who saw the real limit will not tell you...

you can go and ask a submariner at which real depth from his experience the boat has been crushed due to waterpressure...

[RalphTheMouth]

NO real pilot will intentionally go significant beyond barber pole to test at which speed he looses control and the aircraft seperates.[sic]Agreed.

Apparently the "hijackers" of 9/11 were "real pilots". Why did they exceed the Barber pole/red line by 120-150 knots if they were taught that exceeding such limits could cause aircraft structural failure or loss of control? How would exceeding Red line by such a wide margin be constructive to completing their mission?


the pilots who saw the real limit will not tell you... Agreed, But Flight Data Recorder data will.

9/11: World Trade Center Attack Speed Analysis (http://pilotsfor911truth.org/wtc_speed)

I notice your registration date to Pprune. Are you willing to agree with "ADDIS77" and "GR53" that it is "easy" to control an aircraft at Vmo+150? Especially for a pilot with less experience than one who couldn't hit a runway in a 172 at 65 knots?

Are you willing to put you name to it?

If so, numerous verified 757/767 Captains from American and United Airlines, including NASA Flight Engineers who designed high performance flight control systems, disagree with you.

Just google "Pilots For 9/11 Truth" and click the left margin for their names and credentials.

You may also want to google "patriots question 911" to see,

1200+ Engineers and Architects (http://patriotsquestion911.com/engineers.html)
250+ Pilots and Aviation Professionals (http://patriotsquestion911.com/pilots.html)
300+ 9/11 Survivors and Family ... (http://patriotsquestion911.com/survivors.html)
400+ Professors Question 9/11 (http://patriotsquestion911.com/professors.html)
200+ Artists, Entertainers, and Media ... (http://www.google.com/url?sa=t&source=web&cd=1&sqi=2&ved=0CBsQqwMoBDAA&url=http%3A%2F%2Fpatriotsquestion911.com%2Fmedia.html&rct=j&q=patriots%20question%20911&ei=XLC-TJvJNISKlwfZlLXqBw&usg=AFQjCNE6rCAZn1ze55Ldyjtpotz88J26Sg&cad=rja)
Link to full statement (http://patriotsquestion911.com/Zeigler%20Statement.html)

[rudderrudderrat]

Why did they exceed the Barber pole/red line by 120-150 knots if they were taught that exceeding such limits could cause aircraft structural failure or loss of control? How would exceeding Red line by such a wide margin be constructive to completing their mission?
Firstly they were not bothered about using the same aircraft again, and secondly if there had been an attempt to intercept them - then they only needed a "missile on a trajectory".

[aerobat77]

Apparently the "hijackers" of 9/11 were "real pilots". Why did they exceed the Barber pole/red line by 120-150 knots if they were taught that exceeding such limits could cause aircraft structural failure or loss of control?

no, there were terrorists , that is a big difference :) they just firewalled the lever without even knowing what a barber pole is and what affects may come.

I notice your registration date to Pprune. Are you willing to agree with "ADDIS77" and "GR53" that it is "easy" to control an aircraft at Vmo+150? Especially for a pilot with less experience than one who couldn't hit a runway in a 172 at 65 knots?

i dont know since i never in my life exeeded Vmo at 150 knots. and i can tell you NO pilot do such a thing.

If so, numerous verified 757/767 Captains from American and United Airlines, including NASA Flight Engineers who designed high performance flight control systems, disagree with you.

i dont understand. where did they disagree with me? i hope you do not want to say that a real 757/767 captain exeeds Vmo by 100 or more knots in everyday business...

the key in my answer is that you will not get an answer to your question. its a situation a real driver in every case avoids. you can see from 9/11 that a 767 is able to fly far above barberpole- but at what speed this thing will seperate no human pilot will tell you, maybe a black box.

you want this for 9/11 theories?

[RalphTheMouth]

no, there were terrorists , that is a big difference http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif they just firewalled the lever without even knowing what a barber pole is and what affects may come.

Wrong.

They were Commercial, Multi, Instrument rated according to the 9/11 Commission report. You should read it sometime.

But I guess you feel someone who is Comm, Multi, Instrument are not "real pilots" and instead a "terrorist" who hasn't a clue what Red line defines.

[RalphTheMouth]

and secondly if there had been an attempt to intercept them - then they only needed a "missile on a trajectory".

Exactly.

Unless they were in an aircraft which can perform 510 knots near sea level which would prevent the Otis interceptors from reaching them in time.

[aerobat77]

ralph, i think we and the whole world truly can say the people behind the steering of these flights were terrorists and not pilots... its a very sad chapter in aviation history.

[CONF iture]

That 100% of the 'crews' with virtually no experience, managed to precisely hit their target at their very first attempt and so at a speed where even test pilots have probably never been should be matter of question ... no doubt.

[Mad (Flt) Scientist]

Whether the terrorists who piloted those aircraft knew what the barber pole was, or what the significance is of Vmo/Mmo, is frankly irrelevant, because they did not care. They were about to plow into buildings - something I think we can all agree that anyone with a pilot's licence usually tries not to do, and is "trained not to do".

So even if their sim instructors had explained every detail of the flight testing at and beyond Vmo conducted by Boeing, had explained every element of the flight test and certification basis for the definition of Vmo at low altitude, it still would not have mattered. they wanted to fly into those buildings, as fast as they could, to cause the most damage they could.

There is nothing aerodynamically special about Vmo which makes it a cliff-edge past which instant disaster threatens. I've said this before, but every aircraft certified to Part 25 is tested way above Vmo and Mmo, and usually the critical case for handling is Mmo, which they were nowhere near at low altitude.

Flight well above Vmo is dangerous - even very dangerous - because you are compromising all of the dsafety margins built in for cert. But unless you manoeuvre violently, or encounter a severe gust, or heavy turbulence, then there's no real reason the aircraft will suddenly fall apart. It's a stupid thing to do, because you are taking risks that are not required. But they had no intention of completing their flights anyway. Even if they had done it and then lost control at the late stages of the attack (and who's to say the attack on the Pentagon at least didn't?) then the two WTC aircraft would still have come down in downtown Manhattan and caused significant property damage and loss of life. I'm sure the terrorists would have considered that an acceptable result.

[CONF iture]

Mad (Flt) Scientist,

IMO, the question is not as much on VMO or vastly exceeding it, but more on the fact that those 'crews' supposedly successfully adapted in no time from 100 knots on Cessna 172 to 500 knots on Boeing 767 to precisely hit their target, and so with no waste.
Weight and speed make a huge difference on the control inputs with target in sight ...

That capacity for adaptation seems simply miraculous to me.

What did they train for in their simulator sessions if they did any ?
Is that information available ?
Did they only practice 360 knots at 1000 feet ... ?

[Dimitris]

Even if its a conspiracy and they did all those that you suggest Rulph, why would they fly it at +100-150knts in a way that 'no pilot could'?
So that its SO obvious that the planes were modified and RC controlled?

So the possibilities that I see are:
you are smarter than the conspirators (don't take it personally but I doubt)
its not a conspiracy
it is a 'conspiracy' and they want people to 'find out' via conspiracy theories so that nobody in the end believes its a conspiracy.The last bullet obviously means that you are helping the people you want to expose --> bullet no1.

Maybe do a study to find out IF the buildings could collapse being hit by a plane flying at Vmo and then we see how your theory hold up.

I'm no pilot, but it seems the thread has strayed off.

I'm aeronautical engineer though, so my suggestion for the above study has some value in relevance to the thread... Instead of a witch hunt, check in a 'scientific' way why the planes would fly that fast. And I doubt any AAM or PAC2/3 cannot outrun an airliner.

If you think that speed helps avoid interception (at least from fighterplanes), check out the stall speed of modern fighters and also check out why governments around the world equip AFTER 9/11 small turboprop planes (Texan II etc) with machine guns.. Unless thats a conspiracy also..

Cheers

[aerobat77]

IMO, the question is not as much on VMO or vastly exceeding it, but more on the fact that those 'crews' supposedly successfully adapted in no time from 100 knots on Cessna 172 to 500 knots on Boeing 767 to precisely hit their target, and so with no waste.

so what...? the goverment by itself captured the planes and let it land at area 51, then eliminated all passengers and the own kidnappers, removed the real planes and let intentionally crash rc controlled 767 in the wtc...?

that would be much better than the moon hoax conspirancy !

[RalphTheMouth]

That capacity for adaptation seems simply miraculous to me.Exactly CONF iture. That is why you see so many high time heavy jet Capts, NASA Engineers, etc, speaking out at Pilots For 9/11 Truth and the list is growing.

For those who keep repeating "Conspiracy Theory".

Conspiracy - 2 or more people planning and executing to achieve a goal.

Theory - a proposed explanation which has not been proven.

The government explanation:

"19 Muslim terrorists under the guidance of Osama Bin Laden planned, hijacked and crashed 4 aircraft on 9/11 due to the fact they hate our freedoms"

Now here are just some of the facts:

F.B.I. Counsel: No Attempt Made By F.B.I. To Identify 9/11 Aircraft (http://pilotsfor911truth.org/forum/index.php?showtopic=11408)

FBI Refuses To Confirm Identities of 9/11 Aircraft (http://pilotsfor911truth.org/forum/index.php?showtopic=9417)

9/11 Aircraft 'Black Box' Serial Numbers Mysteriously Absent (http://pilotsfor911truth.org/forum/index.php?showtopic=11066)

OFFICIAL ACCOUNT OF 9/11 FLIGHT CONTRADICTED BY GOVERNMENTS OWN DATA (http://pilotsfor911truth.org/pressrelease.html)

United 93 Data Provided by US Government Does Not Support Observed Events (http://pilotsfor911truth.org/UA93_Press_Release.html)

FBI says, it has “No hard evidence connecting Bin Laden to 9/11” (http://www.informationclearinghouse.info/article13664.htm)

The only Conspiracy Theory that has been offered is by the 9/11 Commission. A Commission who admits they were set up to fail.

Please let us know when you find one verified pilot willing to support claims made that it is "easy" to control a 767 at Vmo+150, Va+220 --and pull G's-- out of a 10,000+ foot dive, while rolling on G's cranking into a 38 degree bank, to hit a target with less than a 25' margin for error - for a pilot with less experience than one who couldn't control a 172 at 65 knots to hit a runway and was refused to rent a 172.

So far, the only evidence that has been offered to support the govt version of events is, "Because the govt told me so...". All data and evidence provided thus far conflicts with the govt story.

Here are some more choice quotes regarding the pilot skill of the "most experienced hijacker", (according to the 9/11 Commission):"weak student" who "was wasting our resources."

I didn't allow him to come back. I thought, 'You're never going to make it.' Source (http://web.archive.org/web/20020605061403/http://www.capecodonline.com/cctimes/archives/2001/oct/21/hanjour21.htm)

He also was trained for a few months at a private school in Scottsdale, Ariz., in 1996, but did not finish the course because instructors felt he was not capable.Source (http://www.jrnl.com/cfdocs/new/pg/story.cfm?caldate=09182001&;paper=pg&;section=fp&;snumber=04)

instructors regarded him as a poor student, even in the weeks before the attacks.

"He had only the barest understanding what the instruments were there to do"

got overwhelmed with the instruments." He used the simulator perhaps three or four more times, Fults said, then "disappeared like a fog." Washington Post, 10/15/2001 (http://web.archive.org/web/20020605061403/http://www.capecodonline.com/cctimes/archives/2001/oct/21/hanjour21.htm)

"He could not fly at all." -New York Times (5/04/02) (http://www.nytimes.com/2002/05/04/national/04ARIZ.html)

flying skills were so bad...they didn't think he should keep his pilot's license.

" I couldn't believe he had a commercial license of any kind with the skills that he had." Peggy Chevrette, Arizona flight school manager."CBS News (5/10/02) (http://www.cbsnews.com/stories/2002/05/10/attack/main508656.shtml)More here...
Scene From: "9/11: World Trade Center Attack" - Control (http://pilotsfor911truth.org/forum/index.php?showtopic=18090)

The above type of pilot was able to control a 757 and 767, at Vmo+150, to hit targets with a 25' margin for error laterally (WTC) and a 33' margin for error vertically (Pentagon), with zero time in type yet couldn't even control a 172 at 65 knots to hit a runway?

I don't think so.

Is everyone enjoying their Naked Body Scanners? :)

[aerobat77]

Please let us know when you find one verified pilot willing to support claims made that it is "easy" to control a 767 at Vmo+150, Va+220 --and pull G's-- out of a 10,000+ foot dive, while rolling on G's cranking into a 38 degree bank, to hit a target with less than a 25' margin for error - for a pilot with less experience than one who couldn't control a 172 at 65 knots to hit a runway and was refused to rent a 172.

interesting point, i give you right here.but again- so what???

what is your quess?

[RalphTheMouth]

interesting point, i give you right here

Yes, it is interesting. Thank you.

but again- so what???

The events of 9/11 are the catalyst which changed our world. If you are a pilot, you experience some of those changes every day going through the terminal. Not to mention 2 wars, both without justification, the Patriot Act(s), Military Commissions Act, Suspension of Habeaus Corpus and the right to due process, the shredding of the US Constitution, the list goes on and on and is getting worse. That is why so many Patriots want to know exactly what happened on 9/11 and the list is growing.

There is a growing mountain of data and evidence which conflicts with the govt version of events regarding 9/11.

what is your quess?

Sorry, I only deal in facts and data, but you are welcome to speculate and offer theory.