Yet another Boeing 737 crashes, but this time no one was killed. The flight crew masterfully rejected a takeoff that went wrong. Loud noises were heard that were reminiscent of the sounds identified just before domestic flights on United 585 and USAir 427 rolled over and dived to the ground, killing a total of 152 people in 1991 and 1994 respectively, and overseas airlines COPA 201 and SilkAir 185 crashed, taking the lives of another 151 people in 1992 and 1997.
If I were the NTSB investigator in charge, I would pull the rudder actuator and take some SEM photographs to see if the actuator bears a resemblance to the three other actuators that showed witness marks of jamming.
In my opinion, the Boeing 737 still does not have a reliably redundant rudder control system, and even after hundreds of deaths, the FAA allowed Boeing to build an entirely new generation of B-737’s with a single rudder actuator when all of its other aircraft have at least two.
Noises heard on earlier cockpit voice recorders were the death sounds of an aircraft about to go out of control. These sounds are generated by the hydraulic system telegraphing its agonizing inability to control the rudder. At speeds below 190 knots, the rudder will cause a rapid roll of the aircraft that cannot be stopped before tragedy occurs.
While redesigned after the accidents of the 1990’s, the rudder control system still has no true redundancy. If the flight crew of this aircraft sensed that they were about to lose directional control, they saved themselves and all their passengers from certain death.
The airplane is trashed and some people were hurt, but everyone will ultimately go home to their families this Christmas. Congratulations to a “heads up” Continental crew.
Arthur Alan Wolk
December 22, 2008
