AA Flight 587 accident at JFK:
All the Ph.D's and the Aero. Engineers at the AA 587 NTSB hearing, have not figured out the probable cause, even after seeing the picture of the vertical stabilizer showing the three rudder actuators completely severed from the rudder!
Airbus states flatly that the rudder was pilot commanded.! The rudder movements were so rapid, and in opposite directions, that no pilot could or would operate the rudder in such a manner.!
At some point in time the 0.3, 0.4 and the 0.8 G forces from the rotating vortices, of the B747, struck the vertical fin and rudder, BROADSIDE, and severed the rudder linkage to the actuators.
The rudder is now freely floating and moves in the direction of the wind shear forces. These wind shear forces are also striking the vertical fin, BROADSIDE, and now we have an additional, and very effective, flight control surface.
The large, two engine jet transport design requirement for a large vertical stabilizer, for engine out on take-off control, has created a very large, weather-vane design.
The 0.8 G force against the left side of the vertical control surface induced an abrupt, left yaw of 10 degrees/sec., into an instantaneous Dutch roll, with a left bank through 25 degrees and a pitch down to -30 degrees.!
Although the pilot used full opposite aileron to counter the radical roll to the left, he did not have the use of right rudder to assist the aileron in countering the left bank.! He had no control of the rudder.!
ATC released AA 587 15 seconds early and then turned him inside the path of the departing heavy B747. AA 587 made a perfect join-up on a horizontal tornado, the 747's vortex.!
For improved flight safety..
William Sherriff
Capt. AAL (Ret)
Flight Safety Consultant
Last edited by wsherif1; 10th Jun 2003 at 06:45.