Cessna 172N Skyhawk, Wheels Down LLC, N734GM: Accident occurred August 02, 2016 at Smithfield Airport (MT65), Lewistown, Fergus County, Montana

Aviation Accident Final Report  -  National Transportation Safety Board: https://app.ntsb.gov/pdf

WHEELS DOWN LLC: http://registry.faa.gov/N734GM

FAA Flight Standards District Office: FAA Helena FSDO-05

Docket And Docket Items -  National Transportation Safety Board:   https://dms.ntsb.gov/pubdms

Aviation Accident Data Summary - National Transportation Safety Board:   https://app.ntsb.gov/pdf

NTSB Identification: GAA16CA419
14 CFR Part 91: General Aviation
Accident occurred Tuesday, August 02, 2016 in Lewiston, MT
Probable Cause Approval Date: 01/18/2017
Aircraft: CESSNA 172, registration: N734GM
Injuries: 1 Uninjured.

NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.

According to the pilot, during the takeoff roll about 30 knots indicated airspeed, his seat slid back a few inches. He reported that, "The slight movement of the pilot seat aft during takeoff roll was inconvenient. Had I done nothing at this point, it most likely would have been a manageable situation." However, the pilot reported that, "My reaction to move the seat forward using the adjustment bar during takeoff roll acceleration is what caused the pilot seat to move to the full aft position." He reported that the full aft seat movement caused him to pull back on the yoke, the nose landing gear came off the ground, and the airplane veered left and exited the runway to the left, and struck a fence before coming to a halt. The airplane sustained substantial damage to both wings, horizontal stabilizer, and elevator.

The pilot reported that there were no mechanical malfunctions or anomalies with the airplane during the takeoff roll that would have prevented normal flight operations.

Federal Aviation Administration Aviation Safety Inspector's examined the pilot's seat, track and adjustment assembly and found that there were no failures or anomalies.

According to the manufacturer's Pilot Operating Handbook, item number three of the Before Start Checklist states: Seats/Belts –Adjusted and locked

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's failure to ensure that his seat was adjusted and locked, which resulted in his seat sliding aft during the takeoff roll, and the subsequent loss of directional control and runway excursion.