NTSB Factual Report

On May 26, 2012, about 1025 eastern daylight time, a Cessna A188B, N9629G, registered to and operated by Rebecca Lynn Flying Service, Inc., collided with trees during a forced landing near Dansville, New York. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 137 aerial application flight. The airplane sustained substantial damage, and the commercial pilot, the sole occupant sustained minor injuries. The flight originated about 25 minutes earlier from Hornell Municipal Airport, Hornell, New York.

The pilot stated that the flight departed with 7/8 capacity fuel in each fuel tank, and approximately 11 quarts of oil in the engine. After takeoff the flight proceeded to the spray location, and he executed approximately 20 spray passes. At the completion of the next spray pass or nearing the end of his load, the engine lost power insufficient to sustain flight. At that time the fuel tanks had about 3/4 capacity. He maneuvered the airplane for a forced landing and during the descent, the airplane collided with trees. The airplane came to rest on its right side with the left wing separated. The airplane was recovered for further examination.

Inspection of the engine was performed by a representative of the engine manufacturer with Federal Aviation Administration (FAA) oversight. Inspection of the airframe was also performed by FAA airworthiness inspectors. The inspection of the airframe revealed both wings were separated, while the inspection of the cockpit revealed the electric fuel boost pump switch was in the off position. Inspection of the engine revealed the engine controls remained attached to the throttle body/metering unit and moved freely by hand from stop to stop. Crankshaft, camshaft, and valve train continuity were confirmed. Clean blue colored fuel consistent with 100 low lead (100LL) was noted in fuel lines in the engine compartment. Rotation of the crankshaft by hand produced spark at the upper ignition leads (the bottom were not inspected during this test). Inspection of the spark plugs revealed normal operating signatures when compared with the Champion Aviation Check-A-Plug chart. The engine-driven fuel pump was inspected and found to rotate freely; the drive coupling was intact. Examination of the oil filter revealed oil, and a small amount of blue and orange colored flakes; the orange colored flakes were consistent with the coating on the valve springs. The engine was removed from the airframe, boxed, and sent to the manufacturer’s facility for an attempted engine run.

With FAA oversight, the engine was removed from bonded storage, and impact damaged components were replaced for the engine run. The engine was placed on a test stand with a test club propeller installed. Safety concerns precluded a full operational test of the engine because of impact damage to the crankshaft. The engine was started, allowed to warm up, then operated normally throughout the tested power range. A report from Continental Motors, Inc. is contained in the NTSB Public Docket for this case.

The rebuilt engine was assembled by Continental Motors, Inc., on April 16, 2012, and installed in the accident airplane on May 25, 2012. The recorded tachometer time at the time of installation was 301.1 and the tachometer time at the time of the accident was 302.7, or an elapsed time of 1.6 hours.

NTSB Probable Cause

A partial loss of engine power for reasons that could not be determined because postaccident examination of the engine did not reveal any anomalies that would have precluded normal operation.