Accident Summary
On May 10, 2014, about 1305 central daylight time, a Mooney M20TN, registration N563JK, sustained substantial damage during a forced landing after a loss of engine power while landing at Stinson Municipal Airport (SSF), San Antonio, Texas. The private pilot received serious injuries. The aircraft was registered to Chaparral Equipment Leasing LLC and operated under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight had departed SSF about 1250 for a local flight.
Pilot Report
The pilot reported a normal preflight and that the aircraft was fueled with 70 gallons of aviation fuel. He performed one takeoff and landing on runway 14 without incident. During a second takeoff from runway 14, he extended the upwind before turning crosswind due to another aircraft landing on runway 09. He erroneously turned final for runway 09, but the air traffic controller alerted him, and he corrected to enter a base leg for runway 14. The pilot stated that airspeed dropped below 80 knots, so he advanced the throttle forward 1/2 to 3/4, but the engine stopped producing power. Unable to regain power, he executed a forced landing into a small clearing along riverbanks and baseball fields. Due to low airspeed and confined area, he did not flare, resulting in a hard impact. The AmSafe airbags deployed, and the pilot exited the cabin to the wing, where first responders assisted him.
On-Site Examination
Federal Aviation Administration inspectors examined the wreckage on site and found no apparent reason for the loss of engine power. The wreckage was transported to a storage facility for further examination.
Detailed Examination
Subsequent examination revealed two propeller blades bent aft and one straight. Throttle, mixture, and propeller controls had continuity from cockpit to engine components. All fuel lines were connected forward of the engine firewall with no evidence of a leak. The fuel manifold on top of the engine was removed and found to contain fuel with no obstructions, water contamination, or malfunction. Due to impact damage, the engine was sent to Continental Motors for examination and an engine run.
Engine Test
On September 10, 2014, the engine was examined and run at Continental Motors. Impact damage was concentrated on the left side exhaust, requiring replacement of the left exhaust runner, turbo, and tail pipe. The external surfaces were undamaged except for the No. 6 cylinder rocker cover, which was replaced. Both turbo cans were replaced. A dye penetrant inspection of the crankshaft propeller mount flange showed no cracks. The fuel manifold valve was reinstalled for the test. During installation, the fuel pump exhibited a leak at the mixture shaft and was replaced with a slave pump; the original fuel pump later tested with no leak on a bench and was reinstalled. A second test run with all original components showed no leaks. The engine started normally on the first attempt and was advanced through various rpm steps, including a full-power hold and rapid throttle movements from idle to full power six times, performing normally without hesitation or interruption. The right magneto showed a 240 rpm drop due to impact-damaged ignition leads. Throughout the test, the engine accelerated normally and demonstrated rated horsepower.
Probable Cause
The investigation did not identify a probable cause for the loss of engine power.