Improper Maintenance Resulted In "Complete Loss Of Power"

The NTSB has determined that an accident near West Palm Beach, FL, in May, 2009 was caused by a total loss of engine power due to disengagement of the idler gear support pin as a result of improper maintenance.

The aircraft, a Beech K35, was substantially damaged during a forced landing, after it experienced a loss of engine power during the initial climb from Palm Beach County Airport (KLNA), Lantana, Florida. The certificated commercial pilot and the passenger/owner of the airplane were killed. Visual meteorological conditions prevailed and no flight plan had been filed for the local flight.

According to witnesses, during the initial climb after takeoff and as the airplane reached an altitude of 75 to 100 feet above the ground, the engine ran rough momentarily and then lost power. The airplane entered a right descending turn back toward the airport, where it struck two parked, unoccupied airplanes before impacting the ground and colliding with a tractor-trailer container. Subsequent inspection of the engine revealed that the idler gear support pin was backed-off from its proper mounting position. In addition, the two mounting studs did not contain any mounting hardware, and their respective threads were undamaged. A review of maintenance records revealed that the airplane had been operated for about 2 hours since the engine was disassembled for "extensive engine repair due to spalled cam and lifter bodies," about 5 months prior to the accident, and since its most recent annual inspection, which was performed about 1 month prior to the accident. An engine test run that was conducted after the idler gear support pin was properly installed did not reveal any other engine anomalies.

The pilot, age 68, held a commercial pilot certificate, with ratings for airplane single and multiengine land airplanes, and instrument airplane. He was seated in the front left seat. He reported 2,450 hours of total flight experience, with 15 hours accumulated during the past 6 months, on his most recent application for an FAA second-class medical certificate, which was dated on the day of the accident.

The owner/passenger held a private pilot certificate. He reported 2,268 hours of total flight experience on his most recent application for an FAA third-class medical certificate, which was issued on July 26, 2005. He was seated in the front right seat.

The five-seat, low-wing, retractable-gear airplane was manufactured in 1959. It was powered by a Teledyne Continental Motors IO-470-C series, 250-horsepower engine, equipped with Beechcraft propeller. According to FAA records, the airplane was purchased by the owner/passenger on July 15, 2005.

Review of maintenance records revealed that at the time of the accident, the airplane had been operated for about 2 hours since the engine was disassembled for "extensive engine repair due to spalled cam and lifter bodies" on December 5, 2008, and since its most recent annual inspection, which was performed on April 1, 2009. The airplane had been operated for about 20 hours during the 3 years prior to the accident.

FMI: www.ntsb.gov