Accident Overview
On September 17, 2011, at approximately 1807 eastern daylight time, a North American AT-6, registration N217RK, crashed after experiencing a loss of engine power during takeoff from runway 8 at Hat Field Airport (5N7) near Nunica, Michigan. The runway was 3,600 feet long and 100 feet wide, consisting of dry turf. The commercial pilot was seriously injured, and the airplane sustained substantial damage to the firewall, fuselage, and wings.
Flight Details
The aircraft, registered to Tailwinds Inc., was operated by the pilot under 14 CFR Part 91 as a personal flight. Day visual flight rules (VFR) conditions prevailed, and no VFR flight plan was filed. The flight was originating at Hat Field Airport and was destined for Mason Jewett Field Airport near Mason, Michigan.
Sequence of Events
A video recording at 5N7 showed the accident airplane as the fourth in a formation of multiple airplanes departing. The video captured the airplane losing power during takeoff, striking a tree on the left side of the departure runway, and then impacting the ground.
In his accident report, the pilot stated that each aircraft took off in a single-ship sequence with nine-second intervals, allowing time to abort. He applied full takeoff power, and as the airplane passed about two-thirds of the runway, it had a positive rate of climb. The low fuel pressure light illuminated just before gear retraction, fuel pressure dropped to zero, and the engine abruptly quit. The pilot lowered the nose and struck a tree during the forced descent, which turned the plane and caused it to hit the ground at a vertical angle, tearing the engine and propeller from the airframe.
Fuel System Examination
According to the pilot, the airplane was refueled to its full capacity of 110 gallons (106 gallons usable) prior to flying to the accident airport. The aircraft had two 55-gallon fuel tanks, one in each wing, and a fuel selector with four positions: right tank on, left tank on, left tank reserve, and off. The pilot estimated that the 50-minute flight to 5N7 consumed 29 gallons, based on start-up, taxi, and flight time, and he verified this via fuel gauges and fuel flow meter. However, he did not visually check the tank contents.
A Federal Aviation Administration (FAA) inspector examined the wreckage. The right fuel tank was full, and the gascolator contained a cup of fuel with a clean screen. The engine-driven fuel pump produced suction when rotated by hand. The fuel selector was found set to the reserve position. The wobble pump operated and produced pressure. The left main and reserve standpipes and screens were correctly installed and unobstructed; the left fuel tank contained about four gallons of fuel.
Instrument Data
The aircraft was equipped with a J. P. Instruments EDM-700 engine monitor that recorded exhaust gas temperature, cylinder head temperature, and battery voltage. It contained approximately 11 hours of data over 18 power cycles. Data from the accident flight (17:58:46 to 18:07:10) and the preceding flight (14:24:00 to 15:28:12) were plotted, revealing no recorded engine anomalies.
Additionally, a Shadin Avionics Miniflo-L fuel flow monitor was installed. This unit requires manual entry of initial fuel quantity and bases calculations on fuel flow. After the accident, it reported 32.5 gallons used and 77.1 gallons remaining, and self-tested as "good."
Pilot's Recommendation
The pilot noted that wearing his seat belt, shoulder harness, and aviation flight helmet likely saved his life. He recommended that pilots always wear safety gear when flying such aircraft.