Post Office Box 90, Clements, Maryland 20624 USA
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February 24, 2002 Captain Ray Lahr (ret.) 18254 Coastline Drive Malibu, CA 90265 Marion C. Blakey, Chairman National Transportation Safety Board 490 L’Enfant Plaza East, S.W. Washington, D.C. 20594 Dear
Ms. Blakey:
In an article about AA587 titled, “Pilots Ask: How Much Rudder Is Too
Much?” (Aviation Week 2/18/02 pg. 44), Frances Fiorino included this
statement: NTSB Chairman Marion C. Blakey stressed the cause of the accident is yet to be determined. What is known about AA587, she said, is that the aircraft experienced two wake encounters, and a series of rudder reversals on the aircraft led to the failure of the vertical stabilizer.
“It is unknown at this point if the rudder movements caused the
stabilizer’s failure or if the movements were caused by the pilots,” Blakey
emphasized.
As a retired airline pilot, I consider it exceedingly unlikely that an
experienced pilot would make a series of rudder reversal inputs if the rudder
was still attached to the aircraft and the rudder was responding properly.
If the rudder itself had already separated from the aircraft, or if it
was nonfunctional and was not responding to pilot inputs, then the pilot, in
desperation, might have been making rudder pedal movements to counter whatever
gyration the rudderless aircraft was experiencing. Where were the above rudder reversals measured? Was it rudder pedal movement or was it actual deflection of the rudder itself? And if it was rudder deflection, was that deflection relative to the fuselage or relative to the vertical stabilizer which itself might have been deflecting? And do the rudder reversals correlate with lateral and rotational accelerations? The answers to these questions should be on the Flight Data Recorder. We are eagerly looking forward to the release of the Flight Data Recorder readout by the NTSB. Sincerely, Ray Lahr cc: Aviation Week, FIRO
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