Event Description
A twin turboprop airplane experienced a hard landing that resulted in the collapse of the nose gear and substantial damage to the airframe. According to the pilot, during the terminal descent approximately 6–7 miles from the airport, the right engine torque meter reading dropped to zero. The pilot indicated that this had occurred before and that the torque would return if the throttle was manipulated. Despite this, the pilot continued with a normal approach for landing.
During the landing flare, the airplane yawed to the right despite the pilot's corrective input of left rudder pedal. The airplane then landed hard, bouncing on the nose twice, which caused the nose wheel strut to break. Subsequently, the aircraft slid approximately 2,000 feet down the runway before coming to a stop.
Ferry Pilot Observations
After the accident, a ferry pilot flew the airplane to a repair facility. The ferry pilot reported that the engine power levers were consistently split throughout the entire ferry flight. To achieve matched engine power parameters, the right power lever had to be positioned about 2 inches forward of the left power lever. This positional relationship remained constant from flight idle to full power settings.
Maintenance Records
Examination of maintenance records revealed no record of compliance with Mitsubishi Service Bulletin No. 097/73-001. This service bulletin was published "to assure the engine and propeller rigging is adjusted within manufactures specifications and to prevent potential degraded flight handling qualities associated with the flight idle power being set asymmetrically or too low."