History of Flight
On May 29, 2010, about 1000 central daylight time, a single-engine Covell RV-4 kit airplane, N74RV, sustained substantial damage when it collided with terrain following a loss of engine power shortly after takeoff from Airman Acres Airport (OK93) in Collinsville, Oklahoma. The private rated pilot and passenger sustained fatal injuries. The airplane was registered to and operated by a private individual. Day visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 Code of Federal Regulations Part 91.
A witness on the airfield observed the airplane start, taxi to the north end of the runway, perform a run-up, and begin the takeoff roll, which appeared normal. When the airplane reached an altitude of about 150 feet, the engine quit and it became quiet. The airplane then made a sharp turn back toward the airport, the left wing dropped, and the nose pointed groundward. The airplane disappeared behind trees, and the witness heard the crash and saw smoke rising.
Personnel Information
The pilot held a private pilot certificate and a repairman-experimental aircraft builder certificate. His most recent FAA third-class medical certificate was issued on August 4, 2009. Review of his logbook did not identify total flight experience, but approximately 330 hours were in the accident airplane. The airplane logged about 0.5 hours in 2009 and 2008, and 8.5 hours in 2007.
Aircraft Information
The Vans RV-4 was built from a kit and completed by the pilot on January 23, 1999. It held an experimental airworthiness certificate in the amateur built category and had accrued about 330 total aircraft hours. The most recent annual (Condition) inspection was completed on July 17, 2009. The airplane was equipped with a Lycoming O-320-D1A four-cylinder air-cooled engine.
Meteorological Information
At 0953, the automated weather reporting station at Tulsa International Airport, about 8 nautical miles south, reported clear sky, wind from 150 degrees at 4 knots, 8 miles visibility, temperature 79°F, dew point 69°F, and altimeter setting of 29.89.
Wreckage and Impact Information
Examination of the wreckage on June 9, 2010, involved the NTSB Investigator-in-Charge, an FAA inspector, and a technical representative from the engine manufacturer. The wreckage comprised left and right wings, empennage, and engine; much of the cockpit/cabin area was consumed by post-crash fire. All major components were accounted for.
The wreckage lay in a grassy pasture off airport property. The initial impact was a small crater about 50 feet from the airplane, which rested upright with collapsed main landing gear. The engine compartment, inboard wing sections, and cabin area sustained heat/fire damage. The rear empennage section, including stabilizers, appeared intact and moved freely.
The forward outboard section of the left wing was buckled toward the wing spar; the rest of the leading edge was wrinkled and ripped. The right wing's leading edge was wrinkled along its entire span. Flight control continuity was established for ailerons and elevator to the cabin; rudder continuity was confirmed to the foot pedals.
One blade of the two-bladed, fixed-pitch wood propeller was fractured and separated near the hub; the remaining blade appeared unmarked. The engine sustained heat damage, with magneto housings partly melted and the fuel pump partly consumed. During examination, the crankshaft was rotated by hand, and continuity through the power and valve trains was established. Compression and suction were confirmed via the thumb method. Spark plugs appeared normal per the Champion Wear Guide. The carburetor was removed and partly disassembled; a trace amount of fluid in the bowl tested positive for water using the paste method. Several rain showers had passed over the area between the accident and examination.
A reason for the loss of engine power could not be determined.
Medical and Pathological Information
Autopsy performed on May 30, 2010, by the Office of the Chief Medical Examiner, Tulsa, Oklahoma, concluded the cause of death as internal injuries due to blunt force trauma. Toxicological testing by the FAA Toxicology Accident Research Laboratory was negative for items tested.