JimBenArm
Based on a true story!
- Joined
- Nov 8, 2006
- Messages
- 13,092
If you want the monkeys to dance, you have to give them bananas!I can't believe anyone gave this braindead topic this much attention.
If you want the monkeys to dance, you have to give them bananas!I can't believe anyone gave this braindead topic this much attention.
I would assume McDonnell Douglas went back and revised their computer simulation software in light of this real-world evidence...Interresting quote in that article:
The IAF (Israeli Air Force) contacted McDonnell Douglas and asked for information about possibility to land an F-15 with one wing. MD replied that this is aerodynamically impossible, as confirmed by computer simulations...
We were talking about the F-15 incident at work a few weeks ago and we all pretty much agreed that the only thing that kept the airplane from falling out of the sky is sheer power, as well as the lift provided by the fuselage and the huge horizental stabs. Not too many airplanes can get away with losing a wing, but I guess the F-15 is one of them.

C'mon man! That's more wing than an F-104's got...
Seriously, I haven't heard about that particular incident. Did it land safely?
What, for me, is more amazing, is that the pilot was able to retain sufficient control of the aircraft to land it. The loss of lift I can see being overcome, but the loss of control surface... wowza.
Welcome to the forum from the resident Squid Bubblehead!New debunker here, USAF Lt Colonel with 22 years experience in the aircraft maintenance area. I have a BS in Aerospace Engineering and 2 Master's - One in Aeronautical Science and one in Strategic Studies.
I've been to YouTube and posted a few comments on the Flight 175 Impossible Speed video negative of pumpitout's theories and the method he used to gather information. Of course my comments were deleted and I was summarily blocked from further posting there, a well-known tactic of the CTists.
Getting a Boeing PR person and a random Boeing engineer to say “that sounds reasonable” hardly counts as proof. I think I can help debunk this “proof” using only public sources.
The airplane is flight-tested and certified to be safe (flutter-free, able to carry gust loads, controllable, etc.) up to Vd (the maximum dive speed). This speed may be found in the type certification documents that are filed with the FAA.. For the 767-200 at Sea Level, this speed can be found in Type Certificate # A1NM, available from the FAA at the follwing web site: <rgl.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/15302e51a401f11a8625718b00658962/$FILE/A1NM.pdf>.
If you want to find it yourself, just do a Google search for “Type certificate A1NM Vd”. This document clearly states that the Vd for a 767-200 is 420KCAS (knots calibrated airspeed). This is the equivalent of 420*1.1516 = 484 mph (calibrated).
At sea level on a standard day, this would also be the true airspeed. As it is, the corrections are small. Now you need to compensate for compressibility to convert to equivalent airspeed. At sea level on a standard day, calibrated airspeed and equivalent airspeed are equal. At 700ft and 420KCAS, we’ll have a downward correction about one knot – say 419KEAS.
Next we correct to true airspeed. Assuming a standard day, the air density at 700 feet is 97.9806% of that at Sea Level. V = Ve /(.979806)^.5 = 419 / 1.01025 = 423.3 knots. Now lets convert to mph. 423.3*1.1516 = 487.5 mph (true).
Remember, the airplane has actually been flight-tested at various altitudes (all the way down to near-sea-level) to establish these values, and in fact, it is standard industry practice to go a bit faster during the flight test and set these Vd values slightly to the conservative side. Consequently, the 767 was flight-tested to about 500mph in a dive near sea-level.
Flight 175 went from 31,000 feet to 800 feet in approximately 9 minutes, attaining a maximum 10,000 fpm dive rate during this maneuver. The aircraft would absolutely have built up enough speed to attain ~500 mph+ during the run in to the WTC.
Next time they ask a Boeing Engineer they need to phrase the question correctly: "Could a 767-200, after diving from 31,000 feet at 10,000 fpm, attain a groundspeed of 500+ mph at 800 feet?"
New debunker here, USAF Lt Colonel with 22 years experience in the aircraft maintenance area. I have a BS in Aerospace Engineering and 2 Master's - One in Aeronautical Science and one in Strategic Studies.
I've been to YouTube and posted a few comments on the Flight 175 Impossible Speed video negative of pumpitout's theories and the method he used to gather information. Of course my comments were deleted and I was summarily blocked from further posting there, a well-known tactic of the CTists.
Getting a Boeing PR person and a random Boeing engineer to say “that sounds reasonable” hardly counts as proof. I think I can help debunk this “proof” using only public sources.
The airplane is flight-tested and certified to be safe (flutter-free, able to carry gust loads, controllable, etc.) up to Vd (the maximum dive speed). This speed may be found in the type certification documents that are filed with the FAA.. For the 767-200 at Sea Level, this speed can be found in Type Certificate # A1NM, available from the FAA at the follwing web site: <rgl.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/15302e51a401f11a8625718b00658962/$FILE/A1NM.pdf>.
If you want to find it yourself, just do a Google search for “Type certificate A1NM Vd”. This document clearly states that the Vd for a 767-200 is 420KCAS (knots calibrated airspeed). This is the equivalent of 420*1.1516 = 484 mph (calibrated).
At sea level on a standard day, this would also be the true airspeed. As it is, the corrections are small. Now you need to compensate for compressibility to convert to equivalent airspeed. At sea level on a standard day, calibrated airspeed and equivalent airspeed are equal. At 700ft and 420KCAS, we’ll have a downward correction about one knot – say 419KEAS.
Next we correct to true airspeed. Assuming a standard day, the air density at 700 feet is 97.9806% of that at Sea Level. V = Ve /(.979806)^.5 = 419 / 1.01025 = 423.3 knots. Now lets convert to mph. 423.3*1.1516 = 487.5 mph (true).
Remember, the airplane has actually been flight-tested at various altitudes (all the way down to near-sea-level) to establish these values, and in fact, it is standard industry practice to go a bit faster during the flight test and set these Vd values slightly to the conservative side. Consequently, the 767 was flight-tested to about 500mph in a dive near sea-level.
Flight 175 went from 31,000 feet to 800 feet in approximately 9 minutes, attaining a maximum 10,000 fpm dive rate during this maneuver. The aircraft would absolutely have built up enough speed to attain ~500 mph+ during the run in to the WTC.
Next time they ask a Boeing Engineer they need to phrase the question correctly: "Could a 767-200, after diving from 31,000 feet at 10,000 fpm, attain a groundspeed of 500+ mph at 800 feet?"
USAFMXOfficerNew debunker here, USAF Lt Colonel with 22 years experience in the aircraft maintenance area. I have a BS in Aerospace Engineering and 2 Master's - One in Aeronautical Science and one in Strategic Studies.
I've been to YouTube and posted a few comments on the Flight 175 Impossible Speed video negative of pumpitout's theories and the method he used to gather information. Of course my comments were deleted and I was summarily blocked from further posting there, a well-known tactic of the CTists.
Getting a Boeing PR person and a random Boeing engineer to say “that sounds reasonable” hardly counts as proof. I think I can help debunk this “proof” using only public sources.
The airplane is flight-tested and certified to be safe (flutter-free, able to carry gust loads, controllable, etc.) up to Vd (the maximum dive speed). This speed may be found in the type certification documents that are filed with the FAA.. For the 767-200 at Sea Level, this speed can be found in Type Certificate # A1NM, available from the FAA at the follwing web site: <rgl.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/15302e51a401f11a8625718b00658962/$FILE/A1NM.pdf>.
If you want to find it yourself, just do a Google search for “Type certificate A1NM Vd”. This document clearly states that the Vd for a 767-200 is 420KCAS (knots calibrated airspeed). This is the equivalent of 420*1.1516 = 484 mph (calibrated).
At sea level on a standard day, this would also be the true airspeed. As it is, the corrections are small. Now you need to compensate for compressibility to convert to equivalent airspeed. At sea level on a standard day, calibrated airspeed and equivalent airspeed are equal. At 700ft and 420KCAS, we’ll have a downward correction about one knot – say 419KEAS.
Next we correct to true airspeed. Assuming a standard day, the air density at 700 feet is 97.9806% of that at Sea Level. V = Ve /(.979806)^.5 = 419 / 1.01025 = 423.3 knots. Now let’s convert to mph. 423.3*1.1516 = 487.5 mph (true).
Remember, the airplane has actually been flight-tested at various altitudes (all the way down to near-sea-level) to establish these values, and in fact, it is standard industry practice to go a bit faster during the flight test and set these Vd values slightly to the conservative side. Consequently, the 767 was flight-tested to about 500mph in a dive near sea-level.
Flight 175 went from 31,000 feet to 800 feet in approximately 9 minutes, attaining a maximum 10,000 fpm dive rate during this maneuver. The aircraft would absolutely have built up enough speed to attain ~500 mph+ during the run in to the WTC.
Next time they ask a Boeing Engineer they need to phrase the question correctly: "Could a 767-200, after diving from 31,000 feet at 10,000 fpm, attain a groundspeed of 500+ mph at 800 feet?"
Obvious appeal to authority fallacy noted. These maneuvers were not witnessed so what does he base his claim on? Russ completely ignores the fact that there were 2 commercial certified pilots in the group that would be able to instruct the other 2 and how to fly and navigate.Boeing is the company who manufactures the planes and the phone calls and responses are employees of Boeing. No one was twisting their arm and "got them" to do anything. It was their opinion. What you are offering is your opinion. Now here is the opinion of someone who actually flew the plane said to have crashed into the tower...
RUSS WITTENBERG: "I flew the two actual aircraft which were involved in 9/11... Fight number 175 and Flight 93, the 757 that allegedly went down in Shanksville and Flight 175 is the aircraft that's alleged to have hit the South Tower. I don't believe it's possible for... a so-called terrorist to train on a 172, then jump in a cockpit of a 757-767 class cockpit, and vertical navigate the aircraft, lateral navigate the aircraft, and fly the airplane at speeds exceeding it's design limit speed by well over 100 knots, make high-speed high-banked turns,.. pulling probably 5, 6, 7 G's... I couldn't do it and I'm absolutely positive they couldn't do it."
Those are the design speed limits. To claim that the aircraft would fall apart the second it exceeded those speeds is baseless.From your source....
Airspeed Limits: VD = 420 KCAS to 17,854 ft/.91M above 23,000 ft, linear variation between these points.
VFC = 390 KCAS to 17,600 ft/382 KCAS at 23,000 ft/.87M above 26,000 ft, linear variation
between these points.
VMO = 360 KCAS/.86M
VLE = 270 KCAS/.82M
VLO = 270 KCAS/.82M
The most conservative estimate put up by any official version to date is 437 knots. And that is at below the Th floor or 1045 feet not 23,000 feet. FEMA estimated as high as 514 knots. Still even so the most conservative estimate is still above the top speed in your link.
You're still short of the official version speed.
This is based on the "airplanes are incredibly hard to fly" fallacy. Landing an airplane is hard. Flying one is not. It would be easier for an amateur pilot to pull those maneuvers since they don't have years of training and experience limiting them to the published maximums.Still below the official version speed and not tested by an amateur pilot.
And claimed to have all been done by an amateur pilot. How does this maneuver at this speed performed by an amateur pilot lend credibility to the official version?
http://www.cbsnews.com/stories/2002/02/25/attack/main501989.shtml
The second plane was flying so fast that it was in danger of breaking up in the air as it approached the south tower, Boeing spokeswoman Liz Verdier told the Times.
“These guys exceeded even the emergency dive speed,” Verdier said. “It's off the chart.”

Yes Zen, the terrorist pushed the throttles to the firewall, and the planes in just a few seconds exceeded normal flying speed, but gee, 10 to 20 seconds above the safe speeds and they hit buildings.http://www.cbsnews.com/stories/2002/02/25/attack/main501989.shtml
The second plane was flying so fast that it was in danger of breaking up in the air as it approached the south tower, Boeing spokeswoman Liz Verdier told the Times.
“These guys exceeded even the emergency dive speed,” Verdier said. “It's off the chart.”