Cessna 172 accident near Lewiston, Montana, August 2, 2016
On August 2, 2016 at about 10:30 pm local time, a 1977 Cessna 172, registered N734GM, was substantially damaged in an accident during takeoff near Lewiston, Montana (Smithfield). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 2, 2016 · about 10:30 pm local time
- Place
- Lewiston, Montana · Smithfield · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172 N, built 1977 · all 172s on the register
- Registration
- N734GM · no longer on the register · serial 17268843
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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 complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Collision during takeoff/land during takeoff defining event
- Loss of control on ground during takeoff
The NTSB's findings
- cause Aircraft › Aircraft structures › Fuselage › Seat/cargo attach fitting › Incorrect use/operation
- cause Personnel issues › Task performance › Use of equip/info › Use of equip/system › Pilot
- cause Personnel issues › Task performance › Use of equip/info › Use of checklist › Pilot
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Not attained/maintained
- Environmental issues › Physical environment › Object/animal/substance › Fence/fence post › Contributed to outcome
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; instructor: airplane single-engine; instrument: airplane; rotorcraft: balloon
- Flight time: 1,132 hours in all; 247 in this make and model; 12 in the last 90 days; 2 in the last 30 days; 878 as pilot in command; 89 on instruments
- Last flight review: October 21, 2015
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 5,970.2 hours
- Last inspection: 100-hour inspection, January 19, 2016
- Maximum gross weight: 2,300 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming 0-360-A4M (piston); 467 hours total
- Operator: Wheels Down LLC
The flight
- Departed from: MT56 Lewistown MT at 10:30 pm
- Destination: BZM Bozeman MT
- Flight plan: none
- Runway 24, 2,646 ft by 50 ft
Weather at the time
- Light: daylight
- Wind: from 090° at 13 knots, gusting 18
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 91°F (33°C), dew point 52°F (11°C)
- Altimeter: 29.96 inHg
- Observation at 9:54 pm from KLWT, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on November 10, 2016. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | FAA Inspector's Statement | PDF, 1 page | View Download |
| 3 | Photos | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.