NTSB Factual Report

HISTORY OF FLIGHT

On April 27, 2009, at 1045 eastern daylight time, a Cessna 172M, N9884Q, operated by LH Underwood Aerial Patrol, Inc., was substantially damaged following a partial loss of engine power and collision with terrain during a forced landing near Chesterfield, South Carolina. The certificated commercial pilot and passenger received minor injuries. Visual meteorological conditions prevailed for the aerial observation flight that originated at Spartanburg Downtown Memorial Airport (SPA), Spartanburg, South Carolina, at 0951. No flight plan was filed for the flight that was conducted under the provisions of 14 Code of Federal Regulations Part 91.

In a written statement, and from conversations with a Federal Aviation Administration (FAA) inspector, the pilot stated that while flying pipeline patrol about 500 feet above ground level, the engine began to run “rough” and lose engine rpm with a corresponding loss of power. The pilot adjusted the carburetor heat, throttle, and mixture controls to the “full” positions, as well as adjusting the fuel selector to all positions, with no change in engine performance. He navigated toward the nearest airport according to his global positioning system, and noted that the engine rpm had decayed to 1900 rpm as the airplane descended. The pilot determined he could not reach the airport, and made an emergency landing in trees.

PERSONNEL INFORMATION

A review of FAA and pilot records revealed that the pilot held a commercial pilot certificate, with ratings for airplane single engine land and instrument airplane. His most recent FAA second-class medical certificate was issued on April 24, 2008. The pilot reported 2,800 total hours of flight experience, of which 1,000 hours were in the accident airplane make and model.

AIRCRAFT INFORMATION

According to the FAA and the pilot’s NTSB Form 6120.1 Pilot/Operator Report, the airplane was manufactured in 1975, and had accrued 10,868 total aircraft hours. The most recent annual inspection was completed April 17, 2008, at 10,023 total aircraft hours. The aircraft was equipped with a Lycoming O-320-E2D, 150 horsepower engine.

METEOROLOGICAL INFORMATION

At 1055, the weather reported at Cheraw Municipal Airport (CQW), about 10 miles from the site, included clear skies and winds from 270 degrees at 3 knots. The visibility was 10 miles. The temperature was 23 degrees Celsius (C) and the dew point was 16 degrees C.

WRECKAGE AND IMPACT INFORMATION

The airplane was examined at the site by the FAA inspector. There was no odor of fuel, and all major components were accounted for at the scene. The airplane came to rest in a thicket of small trees, in a nose-down, right wing low attitude.

Flight control continuity was established to the rudder and elevator. The aileron control wheels moved full travel but neither aileron panel would move. The pilot's seat was broken free of its tracks and rested against the control wheel. The right seat had been removed by the passenger and tossed into the trees along side the airplane. The pilot's door would not open, and both occupants exited through the co-pilots door.

The left main tire and wheel assembly was sheared off during the landing and the left gear was buckled. The nose gear strut was broken off and lay beneath the nose cowling. Impact damage to both wings and the nose were evident at the scene. One propeller blade was bent about 25 degrees and one blade was straight. There was no access to the engine compartment as it was embedded into the trees.

On April 29, 2009, the airplane was recovered from the site and moved to Griffin, Georgia for further examination. During recovery, 12 gallons of fuel were drained from the right wing tank, and 2.5 gallons were drained from the left wing tank. The fuel selector inside the airplane would not shut off the fuel when selected in the off position.

TESTS AND RESEARCH

On May 27, 2009, an engine test run was completed under the supervision of the FAA inspector. The airplane engine started and ran, but would not develop full power. Disassembly of the engine revealed "excessive wear" and a broken exhaust valve.

Examination of the airplane's logbooks revealed the engine was remanufactured at the Lycoming engine factory and shipped from the factory on August 28, 1996. The engine was installed, removed, and then installed on several different airplanes since that date.

The engine was installed on the accident airplane on June 27, 2007 at 5,346.8 hours total engine hours, which was 951.8 hours since major overhaul. The last engine logbook entry was dated April 16, 2008, at 5,967.8 total engine hours, and 1,558.9 hours since major overhaul/remanufacture.

Interpolation of logbook entries and tachometer times revealed that at the time of the accident, the airplane's engine had accrued 6,911.9 total engine hours, and 2,403 hours since major overhaul.

Lycoming Service Instruction SI 1009 AU recommended overhaul at 2,000 engine hours, or at the 12th year of service whichever occurs first. According to the bulletin:

“Engine deterioration in the form of corrosion (rust) and the drying out and hardening of composition materials such as gaskets, seals, flexible hoses and fuel pump diaphragms can occur if an engine is out of service for an extended period of time. Due to the loss of a protective oil film after an extended period of inactivity, abnormal wear on soft metal bearing surfaces can occur during engine start. Therefore, all engines that do not accumulate the hourly period of time between overhauls specified in this publication are recommended to be overhauled in the twelfth year.”

NTSB Probable Cause

The partial loss of engine power due to a broken exhaust valve. Contributing to the accident was the operator's exceedance of the engine manufacturer's recommended time before overhaul.