Key Safety Issue(s)

Three key safety issues were identified:

  • There was structural damage to the wing/pylon aft attachment resulting from the use of a forklift during the maintenance procedure.

  • The flight crew had no means to determine that the left wing had stalled. With the loss of the left engine and its associated electrical power generation, electrical power to the left outboard slat position sensor, the stick shaker motor, the slat disagree warning light system, and the left stall warning computer was lost. Even though there were two (left and right) stall warning systems, there was no crossover information between the two systems to provide appropriate (slats retracted) stall warning information to the flight crew. Loss of the single stick shaker motor would have prevented warning, even with the existence of crossover information.

  • The leading edge device hydraulic actuators did not have an alternate means to lock the slats in place in the event of loss of hydraulic pressure to the system, which allowed the slats to retract.

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