ERA13LA360

During departure from the 1,635-foot-long turf runway, the airplane impacted rocks and trees past the runway end. The pilot reported that he could not recall the events of the accident. One of the four passengers reported that he heard the engine advance to takeoff power "normally" and that he believed that the airplane became airborne before impact. Review of the manufacturer's performance data revealed that, given the atmospheric and loading conditions on the day of the accident, the distance required to take off and clear a 50-foot obstacle was about 920 feet. Examination of the flight control system revealed no mechanical malfunctions or anomalies that would have precluded normal operation. Examination of the engine revealed significant circumferential rubbing, frictional heat discoloration, and material smearing signatures in the power section consistent with the presence of engine power at the time of impact. In addition, the compressor discharge air (P3) line pneumatic "B" nut fitting at the fuel control unit was visibly loose, and the "B" nut could be moved by hand. Further examination revealed that the No. 4 gearbox bolts and washers had been pulled from their threaded seats, likely during the impact sequence. The engine operated normally during postaccident functional checks. To determine the effect of the loose "B" nut fitting on the engine operation, the P3 line was manually manipulated to simulate takeoff vibrations, and the fitting was loosened to the extent possible; however, neither action affected the engine operation.

Airplane Performance According to data obtained from the pilots operating handbook (POH), utilizing the atmospheric and loading conditions present at the time of the accident, the estimated distance to clear a 50 foot obstacle on takeoff was about 921 feet. According to the POH, the gross weight of the airplane was 6,750 lbs. The total weight of the airplane at the time of the accident was 5,539 lbs. Engine Examination The examination was conducted by representatives from Pratt and Whitney Canada (PWC) under the supervision of a senior technical investigator from the Transportation Safety Board of Canada (TSB). The engine displayed light impact damage, and the power section was seized. The gas generator rotor turned freely by hand. Visual inspection of the external cases revealed little to no damage, with no evidence of mechanical malfunction. The gas generator compressor inlet screen revealed ingested organic debris, and the exhaust duct revealed compression and torsional deformation. All power control and reversing linkage connections were intact and displayed no anomalies. The compressor discharge air (P3) pneumatic "B" nut fitting at the fuel control unit was visibly loose, and the "B" nut could be moved by hand. All other connections and locking devices were intact. The power turbine control (Py) displayed no anomalies. The reduction gearbox chip detector was bridged by fine ferrous debris. The oil filter was clean. The compressor turbine guide vane ring, compressor turbine shroud, and power turbine housing displayed no preimpact anomalies. The blade platform exhibited circumferential rubbing as a result of contact with the power turbine guide vane ring. The disc and blades revealed no anomalies. The power turbine was displaced due to deformation of the exhaust duct. The power turbine guide vane ring, interstage baffling, power turbine and power turbine shroud revealed circumferential rubbing with variations of heat discoloration and material smearing with associated hardware. There was no evidence of a turbine blade fracture, bearing fracture, or loss of continuity in the power section. The No. 4 bearing retaining bolts and tab washers were pulled by the outer race from the support web threaded seats and were located in the reduction gearbox sump. The power turbine shaft and bearings displayed no signs of operational anomalies. The reduction gearbox was disassembled and exhibited no preimpact anomalies or indications of rotational contact with the liberated No 4. bearing retaining bolts and tab washers. Engine Functional Test An engine functional test was conducted in a dynamometer test cell in accordance with PWC Overhaul Manual P/N 3021243 Section 72-00-00 "Engine Testing" procedures. A slave power section was installed prior to the test using the original propeller governor assembly. All engine handling checks including acceleration to full power, feathering, a bleed valve closing check and manual override functional checks werecompleted with normal results. To confirm fuel control bellows integrity, the engine was run at 37,000 RPM Ng for 5 minutes with negligible degradation of Ng RPM. To determine the effect of the loose fuel control unit P3 "B" nut fitting, the P3 line was manually manipulated to simulate takeoff vibrations, and the fitting was loosened to the extent possible by the lockwire. Neither action had any effect on engine operation. Radar/GPS Data Three Garmin multifunction display memory cards were recovered from the cockpit and forwarded to the NTSB Vehicle Recorders Laboratory for data download. None of the cards contained information regarding the accident. The ten-seat, high-wing, fixed tricycle-gear airplane, was manufactured in 2010. It was powered by a Pratt & Whitney Canada PT6A-34, 750-shaft-horsepower engine. Review of the airplane's maintenance logbooks revealed that it's most recent annual inspection was completed on March 13, 2013, at which time it had accumulated 498 total hours in service. The engine had accumulated approximately 83 total hours of operation since its last inspection. The turf runway at MA07 was 1,635 feet long by 50 feet wide and was configured in a 01/19 orientation. The runway was surrounded by trees about 50 feet in height. The estimated elevation of the airport was about 135 ft. On August 11, 2013, about 0645 eastern daylight time, a Quest Kodiak 100, N10PZ, was substantially damaged during takeoff from Friends Field Airport (MA07), Westport, Massachusetts. The commercial pilot received minor injuries, and the four passengers were not injured. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the personal flight, which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot reported that he flew the airplane to MA07 the night prior to the accident, at which time he completed most of his preflight inspection for the next day's flight. On the day of the accident, the pilot conducted a brief visual inspection of the airplane prior to departure. The pilot recalled boarding the airplane and taxiing to runway 01 for departure, but stated that he had no further recollection of the takeoff or the accident sequence. Runway 01 was a 1,635-foot-long turf runway. Though the pilot reported to first responders that the engine "sputtered" during the takeoff roll, he later stated that this was an observation that had been passed to him by a witness who had heard the accident. During a telephone conversation this witness stated that he initially heard the engine advance to takeoff power. Moments later he heard the engine "skip" and then heard the airplane impact rocks. A passenger also reported to first responders that the engine "didn't sound right," but later stated that she did not observe anything unusual during the takeoff. One of the passengers, who was the pilot's son, reported that he had previously flown out of MA07 in the accidentairplane, and stated that the airplane normally utilized "the entire [length of the] field" during the takeoff roll. He stated that he was not looking outside during the accident, but heard the engine advance to takeoff power "normally," and believed that the airplane became airborne prior to impacting trees at the end of the runway. The pilot reported that he frequently flew out of MA07, and stated that the airplane customarily attained an altitude of about 400-500 feet above ground level by the time it reached the end of the runway during takeoff. He also stated that he had previously flown out of MA07 and in the accident airplane on multiple occasions with two to four passengers onboard. The 0653 recorded weather at New Bedford Regional Airport (EWB), New Bedford, Massachusetts, located about 10 miles northeast of the accident site, included light wind, 10 miles visibility, sky clear, temperature 14 degrees C, dew point 12 degrees C, and an altimeter setting of 30.07 inches of mercury. According to Federal Aviation Administration (FAA) records, the pilot held a commercial pilot certificate, with ratings for airplane single-engine land and instrument airplane. His most recent FAA third-class medical certificate was issued on May 7, 2013. The pilot reported 2,867 total hours of flight experience, of which 453 hours were in the accident airplane make and model. The pilot reported no history of heart problems, neurological problems, blackouts, or episodes involving a loss of consciousness. The airplane came to rest upright on a heading of about 90 degrees magnetic, about 100 feet past the end of the runway, surrounded by large rocks and heavy vegetation. The propeller was completely separated from and located under the engine. Three of the four blades were bent about mid-span and exhibited nicks and gouges. All four propeller blades displayed evidence of curling and separation of the blade tips. Several dents were observed along the leading edge of the horizontal stabilizer. The elevator was intact and moved freely. The vertical stabilizer remained attached and exhibited wrinkling along the forward spar. The fuel condition lever was found in the high idle position, the emergency power lever was in the normal position, and the throttle was located half way between the idle and maximum thrust positions. The wing flap position selector was set at 35 degrees; however, the flaps were extended 20 degrees. The propeller lever was in the cruise position. The elevator trim was set to takeoff position. A fuel sample was free of water and other contaminants.