NTSB Identification: ERA13FA082
14 CFR Part 91: General Aviation
Accident occurred Saturday, December 08, 2012 in Lake Worth, FL
Probable Cause Approval Date: 01/13/2014
Aircraft: CESSNA 421C, registration: N297DB
Injuries: 1 Fatal.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The twin-engine airplane was released to the pilot (who was also the airplane owner) after an annual inspection and repainting of the airplane had been completed. Before the accident flight, which was the second flight after maintenance, the pilot performed an engine run-up for several minutes before taxiing to the end of the departure runway for takeoff. According to witnesses, the airplane lifted off about halfway down the runway and initially climbed at a normal rate. Several witnesses then observed the airplane suddenly yaw to the left for 1 or 2 seconds, and the airplane's nose continued to pitch up before the airplane rolled left and descended vertically, nose-down, until it disappeared from view. One witness, a flight instructor, said, "The airplane just kept pitching up, and then it looked like a VMC [the airplane’s minimum controllable airspeed with only one engine operating] roll."
Examination of the left engine revealed signatures consistent with contact between the piston domes and the valves. The crankcase halves were separated and the No. 1 cylinder main bearing was rotated, and damaged and distorted severely, with bearing fragments located in the oil sump. Bearing material was also extruded from its steel backing. The No. 3 cylinder main bearing showed accelerated wear and wiping of the bearing material. Damage and signatures consistent with excessive heat due to oil starvation were observed on the No. 1 and No. 3 cylinder main bearing journals as well as the No. 1 and No. 2 cylinder connecting rod journals. The camshaft gear was also damaged, with five gear teeth sheared from the gear. A review of engine maintenance records revealed that no maintenance had been performed on the engine that would have required breaking of crankcase thru-bolt torques (such as cylinder removal) since its most recent overhaul, which was completed more than 3 years and 314 flight hours before the accident flight. The reason for the engine failure could not be determined because of the impact and postaccident fire damage.
Examination of the wreckage revealed that the landing gear was in the down and locked position, the left engine propeller blades were in the feathered position, and the left fuel selector valve was in the off position. Examination of the manufacturer's Pilot Operating Handbook revealed that if properly configured, with the landing gear retracted, the airplane would have been capable of a 500 foot-per-minute rate of climb with only one operating engine on the day of the accident. As found, the airplane was not configured in accordance with the after-takeoff checklist or the engine failure after takeoff checklist.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot's failure to follow established engine-out procedures and to maintain a proper airspeed after the total loss of engine power on one of the airplane’s two engines during the initial climb. Contributing to the accident was the total loss of engine power due to a loss of torque on the crankcase bolts for reasons that could not be determined because of impact- and fire-related damage to the engine. Full narrative available
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