History of Flight
On July 1, 2015, about 1354 central daylight time, a Piper PA-24-250 (N6168P) experienced a loss of engine power after takeoff from runway 18 (3,120 feet by 60 feet, turf) at Rockin M Airport (T14), Quinlan, Texas, and impacted a field. The airplane was destroyed by impact forces and post-crash fire. Both private-rated pilots were fatally injured. The airplane was registered to and operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight that was not operating on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The flight was originating at the time of the accident.
A witness reported that runway 18 at T14 was located about 250-300 yards from his house, west of the airport and slightly north of the runway. He could not see the runway due to trees and brush. He heard the airplane engine start and run for several minutes, then taxi to runway 18. The engine speed was run up and he heard the speed drop slightly as the magnetos were tested. The propeller was cycled three times with the engine speed lowered and the propeller blades making a cutting sound. The engine power was reduced to idle. About 45 seconds later, he heard the engine accelerate and about 2 seconds later full power. He noted the airplane moving away and the engine sound "sounded very strong." He heard the climb out, then power reduction to a cruise climb setting for about 2 seconds. The engine sound then ceased abruptly. About 35-45 seconds later, he heard a "thud." He was impressed by the power the airplane was making.
Personnel Information
The left seat pilot/airplane owner held a private pilot certificate with airplane multiengine land and airplane single-engine land ratings. He reported 4,005 total flight hours and 55 hours in the last six months as of his last airman medical exam, which was a third-class medical certificate dated March 7, 2015, with the limitation: must wear corrective lenses. The witness had flown with this pilot numerous times and was impressed with his knowledge of the airplane and flying ability.
The right seat pilot-rated passenger held a private pilot certificate with an airplane single-engine land rating and a mechanic certificate with airframe and powerplant ratings. He reported 250 total flight hours and 10 hours in the last six months as of his last airman medical exam dated October 2, 2013, with a third-class medical certificate and no limitations.
Aircraft Information
The 1959 Piper PA-24-250, serial number 24-1269, was powered by a Lycoming O-540-A1A5 engine, serial number L-1112-40, and was registered to the left seat pilot on July 26, 2002. Logbook entries showed the last inspection on August 1, 2014, at a tachometer time of 4,048.83 hours and a total time since engine major overhaul (December 17, 2007) of 849.33 hours.
Meteorological Information
The Majors Airport (GVT) automated weather observing system, about 7 nautical miles from T14, recorded at 1355: wind 190 degrees at 12 knots, visibility 10 statute miles, sky clear, temperature 32°C, dew point 30°C, altimeter 30.01 inches of mercury.
Wreckage and Impact Information
The wreckage was about 0.32 nautical miles southeast of the runway center, oriented west-southwest. The airplane was upright with crushing along wing leading edges; the right wing was at about a 45-degree pitch downward angle. The empennage was inverted along the left fuselage. Landing gear was fully extended, and the cockpit flap control handle was in the fully extended position. The cockpit fuel selector was positioned to the right fuel tank. Engine control continuity was confirmed. The propeller blades did not exhibit S-shaped bending or chordwise gouges/scratches consistent with torsion.
On-scene engine examination revealed air expelled and drawn through the top spark plug holes with propeller rotation. Engine drive and valve train continuity was confirmed when the propeller was rotated by hand. Rotation of the left magneto produced sparking; the right magneto could not be rotated due to thermal damage.
Post-accident examination found a liquid consistent with water in the carburetor bowl, which tested positive for water with Kolor Kut. Both fuel pumps exhibited internal brown discoloration and brown material consistent with long-term corrosion, and a liquid consistent with water that also tested positive for water. The instrument panel and tachometer were destroyed by impact and fire.
Medical and Pathological Information
Autopsies for both pilots were performed by the Southwestern Institute of Forensic Sciences on July 2, 2015, and stated that the cause of death for each was blunt force injuries.
The FAA Final Forensic Toxicology Fatal Accident Report for the left seat pilot: no carbon monoxide detected in blood, cyanide testing not performed, no ethanol detected in urine, no listed drugs detected in urine.
For the right seat pilot: carbon monoxide testing not performed due to insufficient sample, cyanide testing not performed, 42 mg/dL ethanol detected in urine, 19 mg/dL ethanol detected in vitreous, no ethanol detected in blood. Putrefaction was present.
Tests and Research
The Piper Comanche Service Manual and Owner's Handbook provide procedures for draining fuel strainers and tanks to check for water or dirt accumulation. The manual emphasizes regular draining of the fuel strainer and sumps.
The accident investigation noted water contamination in the carburetor bowl and fuel pumps.