WPR14FA186

The pilot’s inability to maintain aircraft control due to a partial loss of engine power and an encounter with downdrafts and gusting crosswinds while on final approach to the runway. The reason for the partial loss of engine power could not be determined because postaccident examination revealed no mechanical malfunction or failure that would have precluded normal operation.

During a local sightseeing flight, the pilot noticed that the engine had lost partial power, and he initiated a turn back toward the airport while troubleshooting the loss of power. Despite the pilot's attempts, the engine would not regain full power and was surging and sputtering randomly. The pilot entered the airport's traffic pattern on the downwind leg, and, while on final approach to the runway, the airplane encountered multiple downdrafts and wind gusts. It is likely that, due to the downdrafts and the partial loss of engine power, the pilot was not able to maintain airplane control. The airplane subsequently landed hard short of the runway surface and nosed over, coming to rest inverted. The reported wind conditions around the time of the accident varied between 20 and 70 degrees right of the runway heading and were 14 knots gusting to greater than 20 knots. In addition, a company pilot who landed about 8 minutes before the accident reported that he encountered strong downdrafts and windshear while on final approach to the runway and that he would not have been able to reach the runway if he had a partial or total loss of engine power. Postaccident examination of the airframe and engine revealed no evidence of any preexisting mechanical malfunctions or failures that would have precluded normal operation. The engine was subsequently installed on a test stand and was successfully run through various power settings for several minutes. The reason for the partial loss of engine power could not be determined.

The Page Municipal Airport is a non-towered airport that is equipped with two runways, 7/25, a 2,201-foot long and 75-foot wide asphalt runway, and 15/33, a 5,950-foot long and 150-foot wide asphalt runway. The reported airport elevation is 4,316 feet. Runway 15 features a Visual Approach Slope Indicator (VASI) oriented on a 3-degree glideslope. Examination of the Continental Motors TSIO-520-G (3) C M engine was conducted on July 22 and 23, 2014, at the facilities of Continental Motors Inc., Mobile, Alabama, by the NTSB IIC and representatives from Continental Motors, Cessna Aircraft, and American Aviation. The engine was received secure in a wooden shipping container. The engine was removed and slung from a hoist for further inspection. The oil sump, intake tube into the throttle body, and exhaust pipe were replaced to facilitate an engine run. The propeller governor was removed to facilitate installation on the engine test stand. The engine was started, and ran uneventfully for about 30 minutes at various power settings. No evidence of any preexisting mechanical anomalies was noted during the engine run that would have precluded normal operation and the production of power. The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested, and had negative results. Examination of the accident site revealed that the airplane impacted soft terrain about 390 feet from the approach end of runway 15, slightly left of the runway on a magnetic heading of about 142 degrees magnetic. The airplane came to rest inverted on a heading of about 325 degrees magnetic. Two initial ground scars, consistent with the main landing gear, were observed about 160 feet north of the main wreckage. Both ground scars were about 3 feet in length. All major structural components of the airplane were located within about 30 feet of the main wreckage. Examination of the airplane revealed both wings remained attached to the fuselage. All primary flight controls remained attached to their respective mounts. The right wing leading edge outboard of the landing light cutout was bent downward about 10 degrees, and was buckled in a 45-degree angle extending to the wing tip. The left wing appeared to be undamaged. The fuselage was mostly intact. The structure around the forward baggage compartment was buckled. The engine remained attached to the fuselage structure. Both main landing gear were compressed upward. The nose wheel landing gear was compressed upward into the engine compartment structure. The fuselage roof structure from the left rear side window, aft seat, and rear right door was compressed downward and slightly deformed to the left. The fuselage area aft of the rear windows was compressed and buckled throughout the entire structure. The empennage was mostly intact and bent downward. Flight control continuity was established from the cockpit controls to all primary flight control surfaces. One of the elevator control cables was splayed, consistent with tension overload. Examination of the cockpit area revealed that the beacon and avionics switches were in the "on" position. The throttle, mixture, and propeller controls were in the full forward position. The beacon and fuel pump circuit breakers were in the tripped position. The cowl flaps were in the closed position. The pitch trim wheel indicator was in the neutral position. The wreckage was recovered to a secure location for further examination. During wreckage recovery, about 14 gallons of fuel was removed from the right fuel tank, and 9 gallons of fuel was removed from the left fuel tank. The removed fuel was free of debris. Examination of the recovered wreckage at the facilities of Air Transport, Phoenix, Arizona, on May 13, 2014, was conducted by representatives of Cessna Aircraft, Continental Motors, and American Aviation, under the supervision of the NTSB IIC. Examination of the recovered airframe revealed that all seats with the exception of the number two seat remained attached to the seat tracks via at least 2 feet. All seat backs for the passenger seats were displaced rearward. The number two seat was found separated from the seat track. All lap belt restraints remained attached to their respective attach points. The shoulder harness for the number two seat remained attached to the seat belt. The number one shoulder harness was found loose from the seat belt. No stretching was observed on all of the seat belts. The number one seat had a secondary seat stop installed. The fuel selector valve was operated throughout its entire range, and the valve functioned normally. The fuel boost pump circuit breaker was in the tripped position. Power was supplied to the fuel boost pump through the aircraft circuit breaker, and the fuel pump functioned in the high position only. The system was inspected, and two wires to the dropping resisters for the low operating condition were found separated. The separation was found consistent with impact damage. The fuel line from the boost pump to the fuel strainer was found separated and consistent with impact damage at the inlet to the fuel strainer. Examination of the recovered engine revealed that it remained attached to the airframe via all its mounts. Throttle, mixture, and propeller control continuity was established from the cockpit controls to the engine. All fuel and oil lines remained attached to their respective attach points. The engine was removed from the airframe and subsequently shipped to Continental Motors Inc., Mobile, Alabama, for further examination. The propeller assembly was intact. All three propeller blades remained attached and secure to the propeller hub. Propeller blade "A" was bent aft about 10 degrees at mid span. The blade exhibited multi directional striations throughout its span. A slight amount of leading edge nicks was observed. Propeller blade "B" was bent aft about 10 degrees about 10 inches inboard from the blade tip. The propeller blade exhibited multi directional striations throughout and leading edge polishing near the blade tip. Propeller blade C was bent aft about 90 degrees about mid span, and exhibited chordwise scratches through its span and leading edge gouges near the blade tip. For more information, see the NTSB Accident Site, Airframe, and Engine Examination Summary Report in the public docket for this accident. A review of recorded data from the Page Municipal Airport automated surface observing station (ASOS), revealed at 1553 conditions were wind from 220 degrees at 6 knots, gusting to 14 knots, visibility 10 statute miles, overcast cloud layer at 11,000 feet, temperature 26 degrees Celsius, dew point -1 degrees Celsius, and an altimeter setting of 29.60 inches of mercury. Using the reported weather conditions and field elevation, the calculated density altitude was about 6,932 feet and pressure altitude of about 4,613 feet. The pilot, age 53, held an Airline Transport pilot certificate with an airplane multi-engine land rating and commercial privileges for airplane single-engine land. A first-class airman medical certificate was issued to the pilot on March 3, 2014, with the limitation stated "must wear glasses for near vision." The pilot reported on his most recent medical application that he had accumulated 6,835 hours total flight time. The pilot reported on the Pilot/Operator Aircraft Accident Report Form (NTSB Form 6120.1) that he had accumulated 6,850 hours total flight time of which 45.8 hours were in the accident make/model airplane. He further reported that he had accumulated 40 hours of flight time in the accident make/model airplane within the previous 30 days to the accident, of which 2 hours were in the previous 24 hours of the accident. Review of company training records revealed that the pilot be