Oct 9, 1989
Incident
Minor SAN FRANCISCO, CA
InjuriesNone
Phase of Flight-
ConditionsVMC
OperationFAR 121
Probable Cause
THE EXTREME WEAR AND EVENTUAL FAILURE OF A TORQUE TUBE IN THE INBOARD TRAILING EDGE FLAP SYSTEM. INSPECTION AND LUBRICATION INTERVALS WERE A FACTOR, AS WAS THE PHYSICAL LOCATION OF THE TORQUE TUBE WITH REFERENCE TO EXTERNAL FACTORS.
NTSB CHI90IA006