- Date
- July 17, 2019, 08:28 local (14:28 UTC)
- Place
- Ennis, MT
- Injuries
- 2 minor
- Damage
- Destroyed
- Phase of flight
- Maneuvering
- Aircraft
- N137CAviat A1
- Defining event
- Maneuvering-low-alt flying: Aerodynamic stall/spin
- Weather
- Visual (VMC) · Day
- Status
- Completed · report April 13, 2020
- Report
- Approved by Office Director
- NTSB office
- General Aviation Accidents
- Parties
- FAA
- FAA report
- 20190717011989A
- Case key
- 99879
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 exceedance of the airplane's critical angle of attack while turning at low altitude, which resulted in an aerodynamic stall. Contributing to the accident was the pilot's distraction due to looking at wildlife.
Findings · 3
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
The pilot reported that he was conducting an aerial survey to spot bears. After spotting bears, he flew multiple low-altitude passes to maintain sight of the bears. While maneuvering uphill at a low altitude, his attention was drawn to the bears and away from terrain. When he regained focus, he decided to turn the airplane right, away from rising terrain, but about 90º into the turn, the airplane descended and impacted terrain, and a postcrash fire ensued. The airplane sustained substantial damage to the wings and fuselage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot added that he should have let the observer observe the bears during the low passes.
Factual narrative
The pilot of the tailwheel equipped airplane reported that he was contracted for an aerial survey to spot bears. After spotting bears, he flew multiple low altitude passes to maintain sight of the bears. While maneuvering uphill at a low altitude, his attention was "drawn into the visual of the bear and cubs" and away from the terrain. When he regained focus, he decided to turn the airplane to the right, away from rising terrain, but about 90º into the turn, the airplane descended, impacted the terrain, and a post-crash fire ensued. The airplane sustained substantial damage to the wings and fuselage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot added that he should have let the observer examine the bears during the low passes.
Aircraft
- Registration
- N137C
- Reported as
- Aviat A1 (A)
- Category
- Airplane
- Serial number
- 1453
- Built
- 1999
- Airframe hours
- 3,525
- Engine
- Lycoming O-360-AIP, 180 horsepower, reciprocating
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Part 135
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · June 20, 2019
- Departed
- BZN · Bozeman, MT
- Destination
- BZN · Bozeman, MT
- Flight plan
- Company VFR
- Equipment
- Stall warning system, Satellite tracking 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
- 56
- Injuries
- Minor
- Certificates
- Commercial, Airline transport, Flight instructor
- Airplane ratings
- Single-engine land, Single-engine sea, Multi-engine land
- Instrument ratings
- Airplane, Helicopter
- Medical
- Class 2, With waivers/limitations
- Last flight review
- April 4, 2019
- Seat
- Front
- Restraint
- 5-point
- Flight hours
- 18,000 total · 500 in this make and model · 17,500 as pilot in command · 120 in the last 90 days · 40 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 70 °F
- Observed at
- KRXE, 37 nm away
Docket · 2
The files NTSB released with the investigation on January 9, 2020, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.1 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.