NTSB Determines Pilot Error, Engine Failure Both Factors
The NTSB has issued a probable cause report in an accident which
fatally injured the pilot of a Vans RV-4 kit-built airplane and his
passenger in Oklahoma in May of 2010. The aircraft's engine failed
moments after takeoff, and the pilot was left with few options. The
board determined that one critical decision he made was not the
right choice. The NTSB determined that the probable cause(s)
of this accident to be a loss of engine power shortly after takeoff
for undetermined reasons. Contributing to the accident was the
pilot's decision to make a 180-degree turn at low level.
Vans RV-4 File Photo
CEN10LA276
History Of Flight
On May 29, 2010, about 1000 CDT, a single-engine Covell
RV-4 kit airplane, N74RV, received substantial damage when it
collided with terrain following a loss of engine power shortly
after takeoff from Airman Acres Airport (OK93), 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 14 Code of Federal Regulations Part
91 personal flight.
A witness located on the airfield, first heard and observed the
airplane start, and then taxi to the north end of the runway. He
stated that the pilot did a run-up, taxied to the centerline of the
runway, and then started the take-off run; everything appeared
“normal.” The witness added that when the airplane got
to an altitude of about 150 feet, “the engine quit, and it
got quiet.” The airplane then made a “sharp” turn
back to the airport, the left wing dropped with the nose of the
airplane pointing towards the ground. The airplane disappeared from
sight due to trees; however, the witness reported that he heard the
crash, and then saw smoke rising from behind the trees.
Personnel Information
A review of FAA records revealed that the pilot held both
a private pilot and a repairman-experimental aircraft builder
certificate. His most recent FAA third-class medical certificate
was issued on August 4, 2009. A review of the pilot's logbook
failed to identify his total hours of flight experience; however,
approximately 330 hours were in the accident airplane. The records
also indicate that the airplane flew about 0.5 hours in 2009 and
2008, and 8.5 in 2007.
Aircraft Information
The airplane, which is known as a Vans RV-4 was built from
a kit, and completed by the pilot on January 23, 1999. The airplane
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 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 located
about 8 nautical miles south of OK93 at the Tulsa International
Airport (TUL), Tulsa, Oklahoma, reported; a clear sky, winds from
150 degrees at 4 knots, 8 miles visibility, temperature 79 degrees
Fahrenheit (F), a dew point of 69 degrees F, and altimeter setting
of 29.89.
Wreckage And Impact Information
An examination of the aircraft wreckage was conducted by
the NTSB Investigator-in-Charge (IIC), an FAA inspector, and a
technical representative from the engine manufacturer on June 9,
2010. The wreckage consisted of the left-and-right wings, the
empennage section, and the aircraft engine. Much of the
cockpit/cabin area was consumed by a post-crash fire. The major
components of the airplane were accounted for at the scene.
The airplane wreckage was located in a flat, grassy pasture just
off airport property. The initial impact point was a small crater,
about 50 feet from the airplane. The airplane wreckage was resting
on the ground in the upright position, with the main landing gear
collapsed. The engine compartment, inboard section of each wing,
and cabin area all experienced heat/fire damage during the post
crash fire. The rear section of the empennage, including the
stabilizers appeared intact and moved freely on their hinges from
stop-to-stop.
The forward, outboard section of the left wing was buckled back
towards the wing spar; the rest of the leading edge of the wing was
wrinkled, distorted, and contained rips in the aluminum skin. The
right wing’s leading edge was wrinkled and distorted along
the entire span. Flight control continuity for the ailerons and
elevator were established from the respective control to the cabin
area; continuity for the rudder 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 which
remained attached, appeared unmarked.
The airplane’s engine experienced heat damage from the
fire, with both, left and right magneto housings partly melted,
additionally, the fuel pump was also partly consumed by the fire.
During the examination of the engine, the crankshaft was rotated by
hand; continuity was established through the power and valve trains
to the accessory section. Compression and suction was confirmed
using the "thumb" method. The spark plugs were removed and appeared
“normal” when compared to the Champion Spark Plug Wear
Guide (P/N AV-27). The carburetor was removed from the bottom of
the engine and partly disassembled. A trace amount of fluid
remained in the carburetor’s bowl and tested
“positive” for water using the paste method. It was
also noted that several rain showers had passed over the area and
wreckage, between the time of the accident and the examination.
A reason for the loss of engine power could not be
determined.
Medical And Pathological Information
The Office of the Chief Medical Examiner, Tulsa, Oklahoma,
performed the autopsy on May 30, 2010. The autopsy concluded that
the cause of death was "Internal injuries due to blunt force
trauma".
The FAA, Toxicology Accident Research Laboratory, located in
Oklahoma City, Oklahoma, conducted toxicological testing on the
pilot. The results were negative for items tested.