John David Phelps
Update on David: He fought his battle with cancer to the very end.
David's Phone Message of Nov. 12, 2001
I called that morning to make sure David was not involved in the crash and left my message for him to let me know he was OK. The following is the recording he left for me that afternoon while I was at work.
|It was a while before it was concluded that the crash was
not terrorist related.
We're VERY thankful he's OK.
SIDE NOTE: David sent my other brother, Danny, email explaining the technical nature of the rudder system on the A300 and insight into what happened to cause the demise of that flight. It's short and informative (keep in mind David was trained as a military pilot on an aircraft carrier). It reads:
Response to Danny from David:
"The use of rudder in transport category aircraft isusually limited to correct an asymmetry due to the loss of an engine or for longitudinal control while landing in a crosswind. Several years ago AA training dept. developed a program that was used to train us in recovery techniques in the event of an upset due to stalls, wingtip vortices or whatever. This program encouraged aggressive use of the rudder. Keep in mind that rudders are different from plane to plane and this training was of a generic nature. All former military pilots have had a lot of training in recovering from what we called unusual attitudes. But civilian trained pilots generally do not receive that type of training. Airbus has a strangely designed rudder limiter. The faster you go the more the rudder is limited in it's movement. From 30 degrees either side of neutral at slow speed to 3 degrees displacement at 310 knots and above. All models have limiters but they can be very different. In Airbus the rudder pedal movement is restricted along with the physical restriction. At slow speed the pedal moves about 5 inches at full throw. At high speed the pedal movement is only about 3/4 of an inch. None of us ever knew that because you just don't use it at such speeds. Additionally there is a breakout force that once exceeded, makes it very easy to unintentionally input full throw. Airbus never told us about these design characteristics. They also knew about that training program and never alerted us that what was being taught might not be a good idea. Flight 587 was going around 250 knots when the accident happened. The required pedal input for full throw at that speed is about 11/4 inch. I'm sure that the pilot had no idea he was causing the rudder to reach it's limit each time he pressed on the pedal. All transport category aircraft are designed to certain limits and probably generally exceed those standards. The term for a rudder going from stop to stop is doubling. Tails are not designed to withstand doubling and tripling. Yes it can fail under such aerodynamic pressures, and in fact, this tail failed exactly at it's design limits. So, this accident was caused by a pilot that made the tail fail, but a little system knowledge would have gone a long way toward preventing it. I hope this is informative and not confusing.