Remos Aircraft Gmbh REMOS GX N21GX accident near Glendale, Arizona

Probable cause

A total loss of engine power caused by fatigue cracking and fracture of the crankshaft. Contributing to the accident was the operator’s failure to properly maintain the airplane.

NTSB analysis

The pilot reported that the engine rpm began to fluctuate after lifting off following a touch-and-go landing. The student pilot adjusted the throttle lever and continued the climb. Despite his efforts, the engine rpm continued to decrease and shortly thereafter, the engine and propeller suddenly stopped. The student pilot initiated a forced landing near a road, subsequently impacting terrain.

Examination of the engine revealed the crankshaft was found separated at the No. 3 connecting rod journal. The separated surface areas revealed a fatigue crack that initiated at the journal surface close to the radius transition to a cheek. The fatigue crack propagated partially through the thickness of the crankshaft. The terminus of the fatigue crack could not be identified due to contact damage to the fracture face.

The engine manufacturer’s recommended time between overhaul (TBO) is 1,500 hours. The engine total time since new was 2,856 hours, with no record of an overhaul. The excessive operational time on the crankshaft likely lead to the fatigue crack and ultimate failure of the crankshaft.

Text from the NTSB. Open the NTSB docket for WPR23LA160 for the full record.