Lantana, FL, USA
N111YR
BEECH K35
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.
HISTORY OF FLIGHT On May 6, 2009, about 1125 eastern daylight time, a Beech K35, N111YR, was substantially damaged during a forced landing, after it experienced a loss of engine power during the initial climb from Palm Beach County Airport (LNA), 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. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to witnesses at LNA, the airplane was based at the airport. The airplane departed from runway 15, a 3,421-foot-long, asphalt runway. The airplane reached an altitude of 75 to 100 feet above the ground, when the engine "sputtered" or "coughed" and then "quit." The airplane entered a right descending turn back toward the airport with the landing gear in the extended position and the propeller "wind-milling." The airplane struck two parked, unoccupied airplanes, before impacting the ground, and colliding with a tractor-trailer container. PERSONNEL INFORMATION 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 a Federal Aviation Administration (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. AIRCRAFT INFORMATION The five-seat, low-wing, retractable-gear airplane, serial number D-6081, 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. METEOROLOGICAL INFORMATION A weather observation taken at 1153, at Palm Beach International Airport (PBI), located about 5 miles north of the accident site, wind from 120 degrees at 9 knots; visibility 10 statute miles; scattered clouds at 3,400 feet; temperature 28 degrees Celsius (C), dew point 18 degrees C; altimeter 30.08 inches of mercury. WRECKAGE AND IMPACT INFORMATION The airplane came to rest on a heading about 360 degrees, about 100 feet from the initial contact with the parked airplanes, and about 80 feet from the initial ground contact. The ground scar was oriented on approximately a 280-degree heading. All major components of the airplane were located at the accident site. The aft 11 feet of the airplane structure was separated and remained attached via cables. The remainder of the airframe was located underneath the trailer. The engine separated at the firewall and was located about 75 feet, on a 300-degree heading from the main wreckage. The engine throttle, propeller and mixture controls in the cockpit were observed in the full-forward position. The right wing tip and a majority of the right aileron were separated from the right wing. The inboard 12 inches of the right aileron remained attached. The right flap was observed in the retracted position, and contained crushing damage to its spar. The left wing remained attached; however, the majority of the structure inboard of the aileron, aft of the main spar was compromised. The airplane was equipped with a "v-tail" configuration which utilized an elevator-rudder combination (ruddervator) flight control. The right side of the empennage was intact, the left side exhibited significant impact damage. The left ruddervator bellcrank assembly was fractured. Flight control continuity was confirmed from the left ruddervator control to the bellcrank, and from the bellcrank to the forward cockpit area. Flight control continuity was also confirmed from the right ruddervator control to the forward cockpit area and from both ailerons to the control yoke. The airplane was also equipped with a "throw-over" control yoke, which was found locked, in the left pilot position. The airplane was equipped with an interconnected main and auxiliary fuel tank in each wing. The fuel selector in the cockpit was observed in the left main fuel tank position. Prior to the flight, the airplane's main fuel tanks were "topped-off" with 12.7 gallons of 100 low-lead aviation gasoline. The left wing fuel tanks were compromised during the accident; however, a fuel sample was obtained from the left inboard fuel drain and it was absent of visible contamination. Both fuel tanks on the right wing were intact and fuel was visible at the top of their respective refueling ports. Fuel samples taken from the right wing fuel tanks were also absent of contamination. The propeller remained attached to the engine. One blade was straight and exhibited minor damage. The other blade was bent about mid-span and contained scratches consistent with it sliding along the ground. Initial examination of the engine did not reveal any catastrophic engine malfunctions. Subsequent inspection revealed that the idler gear support pin was backed-off from its mounting position. The fuel pump, fuel servo and both magnetos remained attached to the engine. The engine was rotated by hand using the propeller. Rocker arm movement was observed and thumb compression was attained on all cylinders. In addition, spark was observed on all magneto leads. The top spark plugs were removed. Their electrodes were intact and exhibited gray deposits. The fuel manifold contained fuel and was absent of contamination. A lighted borescope examination of all cylinders did not reveal any preimpact malfunctions. The engine was retained for further examination. The engine was examined further at Teledyne Continental Motors, Mobile, Alabama, on August 11, 2009, under the supervision of an NTSB investigator. The idler gear support pin was found backed-off approximately 1.1935 inches from the crankcase, and .447 inches from the end of the mounting studs. The idler gear support pin was intended to be secured to the engine by a lock washer and nut on two mounting studs. The lock washer and nut were missing from both studs, and their respective threads were undamaged. The distributor gear housing inspection plugs were removed from the left and right magnetos, which were found to be out of timing. According to a TCM representative, the condition of the idler gear support pin was such that the accessory/magneto drive gears were subject to disengagement from the idler gear, which would cause the magneto to engine timing to be compromised. In addition, the work outlined in the maintenance entry from December 5, 2008, would have required removal of the idler support pin. An engine test run that was conducted after the idler gear support pin was properly installed and the magnetos properly timed, did not reveal any engine anomalies. It was noted the No. 6 cylinder head sustained impact damage and was replaced with a suitable cylinder assembly for the test run. Throughout the operational test, the engine accelerated normally without hesitation or interruption in power and demonstrated the ability to produce rated horsepower. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot and passenger, on May 7, 2009, by the District 15 Medical Examiner’s Office, West Palm Beach, Florida. The autopsy reports for both occupants indicated the cause of death as "multiple blunt force injuries." Toxicological testing performed on the pilot and passenger by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma, was negative for drugs and alcohol.
A total loss of engine power due to disengagement of the idler gear support pin as a result of improper maintenance.
Source: NTSB Aviation Accident Database
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