IIRC, it came to light many years later that if certain electrical systems were damaged and the ground crew shut the power down then the CVR would automatically erase the tape.

how off course are we now?

Famous Hoot Gibson maneuver...well boys the plane went through hell and they all came out alive. Good for the plane

Anyone remember the 60 minute Hoot Gibson interview? I do..he said straight to the camera..."every CFI out there thinks I did it, well I didn't...it was the rudder".

Has anyone posted the dissenting opinion of one of the NTSB members on the airbus thing?

Do consider one thing ...on the preceding page one of the posters says the FO did the correct thing on the first wake encounter...and did something different during the second...why would he?

Lots of graphs, reports and other things...but very little on the human side.

If you do something right the first time, why change? Did he panic? Did he have itchy feet?

Interviews with other pilots? Sorry, I've seen too many pilots say different things because it helps their own "six".

I haven't heard of such a thing existing - can you find it?

That question has been asked so many times on this thread that I'm wondering if anyone has read the NTSB's report. It discusses that very question in some detail and provides an explanation that satisfies me.

For the sake of argument

Why read the report? It's much easier to accuse the NTSB of incompetence if you don't read the report OR understand the subject matter. :ugh:

Dozy,

you omit the link to training exercises presented as a wake encounter, where the simulator was manipulated so that it did not respond to pilot inputs while the simulated airplane banked to 90 degrees.

I didn't omit them as an act of commission - feel free to add them!

Dozy,

rather than picking pieces out of the NTSB's reasoning, I'd prefer that thread participants read it for themselves.

Agreed, but for those that can't be bothered, surely it's worth laying the basics out?

For those that want to read the report in full:
http://www.ntsb.gov/doclib/reports/2004/AAR0404.pdf

From what I recall and, I think, is again verified by reviewing the NTSB-sponsored creation of the animation (and a big thanks to SMOC for finding and posting it) is that the 23° left bank that existed at the initiation of the 2nd wake encounter seems (to me at least) to remain essentially constant until the very rapid right control wheel and right rudder applications. I fully recognize that this is simply an animation of the FDR traces – and that the FDR information was (as I recall) produced after being “filtered” from the digital recording to be able to print it as an analog trace – and I would feel a lot more comfortable with a “discussion” of what could have happened to generate the observed control application, rather than have someone simply say that “the F/O sensed a roll acceleration to the left.”

Of course, I certainly entertain the logic of a momentary on-set acceleration being immediately noticed PRIOR to the airplane actually beginning to move (and thereby NOT recorded on the FDR) and have that on-set acceleration recognition prompt the pilot to apply substantial right control wheel deflection simultaneously with substantial right rudder input – BEFORE that acceleration actually produced an FDR-recorded rolling movement. In fact, I think that such razor-thin timing is very likely what actually happened … but I also think that would result from one of only two sets of circumstances:

First – this pilot was always reacting almost before anyone else recognized the need for any reaction – and in my experience that almost never occurs; and

Second – the F/O was bordering on or had reached a panicked mental state.

Unfortunately, THAT I have seen … and believe me, if you’ve ever seen it, you will always remember it! In fact, I think it is entirely possible that the Captain had either noticed or suspicioned something being inconsistent with what he had previously seen from that F/O and that was why he asked “Are you all right?” pretty much AS the F/O applied those extreme control inputs and said “Let’s go for power please.” I think it’s also important to note that the F/O comment on power was annotated as being spoken in “a strained voice” – also a reaction to panic.

Apparently, the F/O continued to apply these substantial control inputs – very likely after the first such input, were made thinking they were necessary to counter what the airplane was doing … and the airplane was merely doing what it was commanded to do by the F/O control inputs.

Again, I take no particular joy in making these comments – but I think it’s a logical way to make all the pieces of the facts make some kind of sense.

OK – I’m ready for the critiques.

Owain, thanks for the pedal vs rudder deflection chart. I have never seen it. I am sure there is no reverse input from the rudders to the pedals so if the graph is correct the inputs were made from the cockpit. I just don't understand why. I don't feel AA pilots can not make mistakes because of the numerous ones in our history. I just feel we need to defend our pilots when there is a question about what input they had in a crash. I feel the same way about other airlines having a crash and blaming the crew. I always try to defend my crew until it is obvious they screwed up. I hope we all do.

NTSB Press Release
National Transportation Safety Board
Office of Public Affairs
________________________________________
NTSB SAYS PILOT'S EXCESSIVE RUDDER PEDAL INPUTS LED TO CRASH OF AMERICAN FLIGHT 587; AIRBUS RUDDER SYSTEM DESIGN & ELEMENTS OF AIRLINE'S PILOT TRAINING PROGRAM CONTRIBUTED

OCTOBER 26, 2004

Washington, D.C. - American Airlines flight 587 crashed into a Queens neighborhood because the plane's vertical stabilizer separated in flight as a result of aerodynamic loads that were created by the first officer's unnecessary and excessive rudder pedal inputs after the aircraft encountered wake turbulence, according to a final report adopted by the National Transportation Safety Board today. The Board said that contributing to the crash were characteristics of the airplane's rudder system design and elements of the airline's pilot training program.

At about 9:16 a.m. on November 12, 2001, flight 587, an Airbus A300-605R (N14053), crashed in Belle Harbor, New York shortly after taking off from John F. Kennedy International Airport on a flight to Santo Domingo. All 260 people aboard the plane died, as did five persons on the ground. This is the second deadliest aviation accident in American history.

The aircraft's vertical stabilizer and rudder were found in Jamaica Bay, about a mile from the main wreckage site. The engines, which also separated from the aircraft seconds before ground impact, were found several blocks from the wreckage site. The Safety Board found that the first officer, who was the flying pilot, inappropriately manipulated the rudder back and forth several times after the airplane encountered the wake vortex of a preceding Boeing 747 for the second time. due to The aerodynamic loads placed on the vertical stabilizer he sideslip that resulted from the rudder movements were beyond the ultimate design strength of the vertical stabilizer. (Simply stated, sideslip is a measure of the "sideways" motion of the airplane through the air.)

The Board found that the composite material used in constructing the vertical stabilizer was not a factor in the accident because the tail failed well beyond its certificated and design limits.

The Safety Board said that, although other pilots provided generally positive comments about the first officer's abilities, two pilots noted incidents that showed that he had a tendency to overreact to wake turbulence encounters. His use of the rudder was not an appropriate response to the turbulence, which in itself provided no danger to the stability of the aircraft, the Board found.

The Board said that American Airlines' Advanced Aircraft Maneuvering Program contributed to the accident by providing an unrealistic and exaggerated view of the effects of wake turbulence on heavy transport-category aircraft. In addition, the Board found that because of its high sensitivity, the A300-600 rudder control system is susceptible to potentially hazardous rudder pedal inputs at higher speeds. In particular, the Board concluded that, before the crash of flight 587, pilots were not being adequately trained on what effect rudder pedal inputs have on the A300- 600 at high airspeeds, and how the airplane's rudder travel limiter system operates.

The Safety Board's airplane performance study showed that the high loads that eventually overstressed the vertical stabilizer were solely the result of the pilot's rudder pedal inputs and were not associated with the wake turbulence. In fact, had the first officer stopped making inputs at any time before the vertical stabilizer failed, the natural stability of the aircraft would have returned the sideslip angle to near 0 degrees, and the accident would not have happened. (The Board estimated that the sideslip angle at the time the vertical stabilizer separated was between 10 and 12.5 degrees.)

The NTSB issued eight recommendations in today's report. Among the seven sent to the Federal Aviation Administration were those calling for adopting certification standards for rudder pedal sensitivity, modifying the A300- 600 and A310 rudder control systems to increase protection from potentially hazardous rudder pedal inputs at high speeds (a similar recommendation was issued to the French equivalent of the FAA, the DGAC), and publishing guidance for airline pilot training programs to avoid the kind of negative training found in American Airlines' upset recovery training.

Because this crash occurred two months after the September 11 terrorist attacks, there was initial concern that it might have been the result of an intentional criminal act. The Board found no such evidence, nor did any law enforcement agencies provide evidence that the accident may have stemmed from criminal conduct. The Board said that witnesses who reported observing the airplane on fire were most likely observing misting fuel released from broken fuel lines, a fire from the initial release of fuel or the effects of engine compressor surges.

A summary of the Board's report may be found under "Publications" on the agency's website at NTSB - National Transportation Safety Board. The full report will appear on the website in about four weeks.

Yup, I remember that discussion. As I recall it related to the "variable stop" rudder pedal limiting system as used on the A300-600. For the record, the same system is used on the DC-8 and DC-9/MD-80-90 series.

32 yrs later and you remember the exact quote? 60 Minutes? Or CBS Reports special?

It wasn't a secret. They'd tell us beforehand - "I'll have control of the simulator to put you in an unusual attitude. At that point I'll let go off the control and you'll be flying."

Sounds like good training to me. I did similar things teaching basic students. JFK JR could have used another session before his crash. I think we have all had vertigo. Training lets us overcome it. It saved my butt once.

Doesn't matter if it behaves differently, it's still the same system.

Always difficult to know what one is thinking but you go through on 747 wake and it may be a surprise even if you discussed it before takeoff. Now you perhaps think quickly if there is a way to try to smooth out the next encounter for the pax in the back. Why not try rudder to reduce the effect. Turns out that Airbus designed a plane with overly sensitive rudders that you didn't realize can easily go full deflection.

Oops, the first rudder input did a huge amount of yaw, better bring it back. Oops went too far the other way with these small pedal inputs that have a large effect. Damn, I am overcontrolling it, good thing we are relatively slow. CRACK.

Meanwhile, the captain assumed that it was bad wake turbulence from that heavily loaded 747.

Only a guess of course.

A300-600R has a light breakout force.

APA submission to the NTSB, page 8 -

http://alliedpilots.org/Public/Topic...submission.pdf


The change in maximum force and degrees of rudder per pound between the A300B2/B4

and the A300-600 is highly significant. The A300 family (should say A300-600R. Look at chart on page 8) has the distinction of having the

lightest breakout force and the highest number of degrees of rudder travel per pound of

force of any other transport category aircraft. Once a pilot initiates rudder movement, he

or she will be challenged with the most sensitive rudder handling qualities of any

transport category airplane. This sensitivity is a precursor to a characteristic known as

Aircraft Pilot Coupling (APC), a condition typically “…not feasible for a pilot to realize

and react to in real time,” and considered unacceptable in U.S. certified designs


(National Research Council 15). Simply, a very light application of force coupled with a

very small movement of the rudder pedal will yield full deflection of the rudder.