AAL A-300 accident
Reply to Ronald A. Hess Ph.D.
University of California-Davis
NTSB selected investigator on the AA 300 accident
Dear Sir:
The recent article in the February 6th issue of "USA Today", which includes excerpts from you own report, continues to infer that the co-pilot of American Airlines’ Flight 587, was the cause of the accident, through overuse of the aircraft’s rudder.
In fact, the co-pilot never had control of the rudder after it was struck by the 0.3 and the 0.4 G forces of the "Heavy" Boeing 747’s vortices! These forces, striking the large rudder surface area, broadside, broke the linkages to the rudder actuators! The rudder was then free floating, reacting to the rotating vortices striking it, alternately, first on one side and then the other. This whipping action of the rudder, back and forth was faster than any pilot would have ever commanded, even if he was physically able to do so!.
The final 0.8 G forces striking the large, vertical Fin surface area, broadside, induced an instantaneous YAW. The resultant massive inertia factor, sheared off both engines from their pylons, the vertical Fin from its support fitting, and broke the rudder into four pieces. The abrupt YAW also initiated an instantaneous
"Dutch Roll", into the ground.
NOTE:
Although the co-pilot used a full right aileron input to counter the steep left bank, there was no evidence that any rudder input was applied, to assist in an attempted recovery maneuver! THERE WASN'T ANY RUDDER INPUT AVAILABLE TO THE PILOT! THERE WASN'T ANY RUDDER!
This was the first accident, of this type, in 100 years!. It was a perfect "Join-up" on the center of a horizontal tornado! (The aircraft wake from the Boeing 747 "Heavy".). NASA states that the angular velocities in a vortex may be as high as 300’/sec.
William J. Sherriff
Capt. Ret.
American Airlines
Last edited by wsherif1; 18th February 2004 at 06:54.