Cessna 177 N29516 accident near Elkhart, Indiana

Probable cause

An inadvertent engine start of the airplane and subsequent takeoff without the pilot on-board for reasons that could not be determined based on available evidence.

NTSB analysis

The pilot preflighted the airplane for a flight with two passengers. The passengers sat in the airplane with their seatbelts secured when the pilot lowered the propeller blade by manually “smacking it down” in a clockwise direction. The engine started, and the airplane began to move forward under its own power. The pilot attempted to board the airplane while it was rolling but was unable to. The airplane traveled across a ramp area, through a grassy area, over a taxiway, and up a slight grade where it became airborne momentarily before it came to rest in a field. The airplane sustained substantial damage.

Postaccident examination of the airplane found the mixture and throttle in the full-forward position and the ignition key removed from the ignition. The key’s position before the accident could not be confirmed. When the pilot rotated the propeller an inadvertent engine start occurred. The reason for the inadvertent start could not be determined based on available evidence.

Text from the NTSB. Open the NTSB docket for CEN19LA223 for the full record.