History of Flight
On July 18, 2011, about 1225 eastern daylight time, a Mooney M20K, registration N777CV, collided with the ground shortly after takeoff from Augusta Regional Airport (AGS), Augusta, Georgia. The airplane was on a maintenance test flight under 14 CFR Part 91, operated by a private individual. Visual meteorological conditions prevailed, and no flight plan was filed. The pilot, who was the sole occupant, was fatally injured. The airplane came to rest on airport property and was substantially damaged by impact and fire.
A witness who taxied behind the accident airplane observed the climb-out and later heard a radio transmission that an airplane had crashed. He saw fire and black smoke across the runway. Other witnesses reported that the airplane's engine sounded extremely loud during initial climb, the airplane climbed slowly, then made a sharp left turn. The engine noise increased followed by a loud "bang." One witness stated the propeller separated from the airplane and fell to the ground, after which the airplane spiraled nose-down and a post-crash fire ensued.
Pilot Information
The pilot, age 58, held a private pilot certificate with ratings for airplane single-engine land and sea, multi-engine land, and instrument airplane. He held a third-class medical certificate issued September 9, 2010, with corrective lenses limitation. His logbook was not recovered. On a September 2010 medical application, he reported 8,000 total civilian flight hours. A July 2011 insurance application indicated 8,400 total hours, with 3,237 in multi-engine and 3,000 in make and model. His last biannual flight review was completed on April 25, 2011.
Aircraft Information
The three-seat, low-wing, retractable-gear Mooney M20K (serial number 25-0149) was manufactured in 1979. It was originally powered by a Continental TSIO-360-GB, 210 hp engine with a McCauley two-blade propeller. In 1995, a Rocket Engineering engine conversion kit (supplemental type certificate SE00223SE) was installed, converting it to a 305 Rocket configuration with a Continental TSIO-520-NB engine and a McCauley three-blade propeller. Maintenance logbooks obtained from Race City Aviation showed an annual condition inspection completed November 26, 2011, at a tachometer reading of 2,614.5 hours. The airplane's logbooks were destroyed in the post-crash fire, and the tachometer was destroyed, so total airframe hours, time since last annual, and total engine hours could not be determined. The airplane was fueled with 40 gallons of aviation gasoline prior to takeoff.
Maintenance History
According to FAA records, the pilot was involved in a previous gear-up landing accident with the same airplane at AGS on April 11, 2011, which caused substantial damage to the propeller and fuselage. Two days before the accident, maintenance personnel prepared the airplane for a ferry flight to Lake Norman Airpark, Mooresville, North Carolina. During a walk-around inspection, a mechanic noted the landing gear was not down and locked and the three-blade propeller was bent. The mechanic secured the gear and removed the three-blade propeller. A two-blade McCauley propeller supplied by the pilot was installed per the Mooney M20K Maintenance Manual. However, the spinner would not fit without cowling interference. The mechanic did not sign off the logbook or ferry permit. Later, the FAA airworthiness certificate application for the ferry permit indicated the shop owner had signed off the work.
On July 15, 2011, another mechanic accompanied the pilot to AGS to reconnect the battery and conduct an engine run-up. During the run-up, the mechanic noticed that with the two-blade propeller, the propeller control operated in reverse: advancing the lever decreased RPM, while retarding it increased RPM. The mechanic stated that personnel at Aero Engines, who had supplied the propeller, advised against flying the airplane in that condition. The mechanic discussed the anomaly with the pilot and advised him not to fly until the issues were resolved.
Meteorological Information
A review of recorded weather data at AGS at 1255 indicated winds from 270 degrees at 6 knots, visibility 10 miles, scattered clouds at 7,500 feet above ground level, temperature 23°C, dew point 6°C, and altimeter 30.06 inches of mercury.
Wreckage and Impact
The wreckage was located on the airfield approximately 50 feet to the left of runway 26, on a heading of 180 degrees. The airframe was consumed by fire and crushed upward; all flight control surfaces were accounted for. The two-blade propeller assembly had separated from the engine flange and was found approximately 1,000 feet forward of the main wreckage. The upper and lower cowlings were fire-damaged. The engine was displaced aft toward the firewall and downward into the ground, with external fire damage. The magnetos and vacuum pump were broken away. The nose wheel assembly was in the retracted position. The cabin area from the firewall aft to the empennage was consumed by fire. The instrument panel and components were destroyed. Continuity of the flight control system was confirmed from the control yoke to all flight control surfaces. The right wing was partially consumed by fire; the right main fuel tank was ruptured with no fuel remaining; the fuel cap was secured. The left wing was crushed upward; the left main fuel tank was ruptured with no fuel; the fuel cap was secured. The empennage was intact and fire-damaged, with control tubes still attached. Examination of the airframe and flight control systems did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation. The engine examination also revealed no preimpact mechanical malfunctions: all pistons moved, compression and valve train continuity were established, and spark plugs showed normal wear. The fuel system components were fire-damaged but the fuel screen was clean and free of debris.
Medical and Pathological Information
An autopsy performed on July 19, 2011, by the Georgia Bureau of Investigation listed the cause of death as "multiple blunt force injuries." Forensic toxicology on specimens by the FAA Bioaeronautical Sciences Research Laboratory detected no ethanol in the liver or muscle and no drugs in the liver.
Testing and Research
Examination of the separated propeller at the NTSB Materials Laboratory found five bolt studs remaining in the hub and one missing (the #6 bolt stud and nut were located separately). Microscopic examination revealed high-stress fatigue propagation in five of the six bolt studs. The fatigue areas initiated in the roots of the first and second engaged threads in the hub. The S1 bolt stud fracture was entirely overstress with bending deformation. The S2 bolt stud showed fatigue from one side through about 70% of the cross section, with twisting deformation in the overstress area. The S3 bolt stud had two opposed fatigue regions penetrating about 60% of the cross section. The S4 bolt stud also showed two fatigue regions from adjacent thread roots, total penetration about 40%. The S5 bolt stud had a single fatigue region through about 40% cross section. The S6 bolt stud had about 10% fatigue from one side, with bending and twisting deformation in the overstress region. The unthreaded grip area on the S6 bolt stud was polished in local areas, and the exposed nut-side threads were flattened and polished, consistent with contact by the crankshaft mounting hole. Both locating dowels were fractured flush with the mounting surface and showed overstress features. The mounting face of the hub exhibited areas of light fretting and localized polishing.