Event Description
A flight experienced a landing gear malfunction after the gear selector handle was lowered. The gear did not fully extend, and emergency extension procedures were unsuccessful. During the subsequent landing roll, the main landing gear collapsed.
Maintenance History
During a previous flight, the landing gear had malfunctioned, requiring emergency extension with excessive force. Maintenance personnel then lubricated the nose gear retract chain and adjusted the gear down indicator switch. The aircraft was flown without any noted discrepancies until the accident flight.
Post-Accident Examination
Examination of the landing gear system revealed that the nose gear actuator was seized due to lack of lubrication. The aircraft logbooks indicated that all gear actuators had been replaced on August 23, 1986, with no further entries showing lubrication. According to the maintenance manual, the actuators should be removed for lubrication every 1,000 cycles of operation or 30 months, whichever occurs first. The aircraft had accumulated 3,154 cycles since the actuator replacement.