- Date
- August 2, 2016, 16:30 local (22:30 UTC)
- Place
- Lewiston, MT
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Takeoff
- Aircraft
- N734GMCessna 172
- Defining event
- Takeoff: Collision during takeoff/land
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 18, 2017
- Report
- Approved by Office Director
- NTSB office
- General Aviation Accidents
- Parties
- FAA
- FAA report
- 20160802012979A
- Case key
- 93775
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
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.
Findings · 6
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
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
Factual narrative
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
Aircraft
- Registration
- N734GM
- Reported as
- Cessna 172 (N)
- Category
- Airplane
- Serial number
- 17268843
- Built
- 1977
- Airframe hours
- 5,970.2
- Engine
- Lycoming 0-360-A4M, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Wheels Down LLC
- Registered owner
- Wheels Down LLC
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · January 19, 2016
- Departed
- MT56 · Lewistown, MT
- Destination
- BZM · Bozeman, MT
- Airport
- MT65 · Smithfield, runway 24, 2,646 × 50 ft, asphalt
- Equipment
- ADS-B, Stall warning system, Electronic flight bag or handheld device
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 48
- Injuries
- None
- Certificate
- Commercial
- Airplane ratings
- Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- October 21, 2015
- Seat
- Left
- Restraint
- 3-point
- Flight hours
- 1,132 total · 247 in this make and model · 878 as pilot in command · 12 in the last 90 days · 2 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 90° at 13 knots, gusting 18
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 91 °F, dew point 52 °F
- Altimeter
- 29.96 inHg
- Observed at
- KLWT, 5 nm away
Docket · 3
The files NTSB released with the investigation on November 10, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.0 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.