Piper PA 28-181 N8740E accident near Las Vegas, Nevada

Probable cause

The engine's inability to produce full-rated power due to wear on internal engine components, which resulted in a loss of altitude and subsequent landing on uneven terrain. Contributing to the accident was the airplane owner's failure to maintain the engine in accordance with the manufacturer's recommended guidance.

NTSB analysis

The private pilot reported that the takeoff seemed normal, but once airborne, the airplane's climb was "sluggish," and the engine rpm was between 200 and 300 rpm lower than normal. He was able to maintain straight and level flight at 300 ft above ground level. When the pilot made a left turn in an attempt to return to the airport, the airplane immediately began to lose altitude. The pilot subsequently landed in an open construction site. During the landing sequence onto uneven terrain, the landing gear was torn off, and the airplane caught fire, which subsequently consumed the airplane.

During postaccident examination of the engine, as the crankshaft was rotated by hand, the travel of the intake valve rockers was about 50% less than normal. Disassembly of the engine revealed wear on the intake lobes of the camshaft and spalling damage on the faces of the tappets. The decreased travel of the intake valves would have reduced the amount of fuel/air mixture allowed into each cylinder, which reduced the overall power the engine could produce.

A review of maintenance records revealed that the engine was last overhauled 28 years before the accident and had accumulated 1,461 hours since overhaul. The engine manufacturer recommended that the engine be overhauled after 2,000 hours of operation or after 12 years, whichever occurred first.

Text from the NTSB. Open the NTSB docket for WPR15LA217 for the full record.