Factual Report: Worn parts eyed in landing gear failure

 - November 25, 2009, 5:30 AM

Hawker Beechcraft King Air A200, Salt Lake City, Utah, July 21, 2008–Following a partial landing gear malfunction, the turboprop twin–which was operated by the FAA–suffered substantial damage to its lower fuselage when
it made a gear-up landing at Salt Lake City International Airport.

During a currency flight, the crew noted an illuminated indicator signaling failure of the gear to retract fully after takeoff. An attempt to recycle the gear resulted in a failure to lock in the down position. The pilot returned to the airport and performed a low flyby of the tower, and the controller informed him that the gear appeared to be down. The pilot attempted a landing; after touchdown, at a speed of approximately 45 knots the main gear partially retracted, causing the aircraft to slide down the runway. The onboard checklist revealed instructions for the manual extension of the landing gear, but the crew made no attempt to manually deploy the gear before landing.

During post-accident investigation, it was discovered that the 60-amp thermal circuit breaker for the landing-gear motor had tripped. Further examination revealed that approximately 60 percent of the gear sprocket teeth were
worn and chipped, one of the sprocket shafts was not completely squared with the gear and at least one of the hanger bearings was worn due to chain rub caused by the previous conditions. According to the operator, the aircraft
had suffered a similar gear malfunction three months earlier.