- Date
- June 8, 2012, 17:00 local (23:00 UTC)
- Place
- Sula, MT
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N2839TPiper PA-28-140
- Defining event
- Enroute-cruise: Windshear or thunderstorm
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 4, 2012
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- FAA FSDO
- FAA report
- 20120608009569A
- Case key
- 83659
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 inability to maintain clearance from terrain while operating in a downdraft over mountainous terrain.
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 the airplane was in cruise flight between 2,000 and 2,500 feet above ground level over mountainous terrain when it encountered a strong downdraft. At full power and at the airplane’s best rate of climb, it was descending 1,500 feet per minute. The pilot stated that he could not turn left because of a mountain and that he was afraid that turning right would result in a greater loss of altitude and a collision with trees. When he was sure that he was not going to clear the terrain, he performed a steep left turn. The airplane subsequently collided with an embankment next to a road with the engine at full power and the stall warning light on.
Factual narrative
The pilot reported that the airplane was in cruise flight at 2,000 - 2,500 feet above ground level over mountainous terrain when it encountered a strong downdraft. At full power and best rate of climb, the airplane was descending 1,500 feet per minute. The pilot stated that he could not turn left because of a mountain, and he was afraid that turning right would result in a greater loss of altitude and a collision with trees. When he was sure that he was not going to clear the terrain, he performed a steep left turn. The airplane subsequently collided with an embankment next to a road with the engine at full power and the stall warning light on.
Aircraft
- Registration
- N2839T
- Reported as
- Piper PA-28-140
- Category
- Airplane
- Serial number
- 28-7225248
- Airframe hours
- 5,810
- Engine
- Lycoming O-320 SERIES, 150 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Raymond E CHATTERTON
- Registered owner
- Raymond E CHATTERTON
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · December 1, 2011
- Departed
- 6S5 · Hamilton, MT
- Destination
- IDA · Idaho Falls, ID
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
- 65
- Injuries
- Minor
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 3, With waivers/limitations
- Last flight review
- December 18, 2010
- Seat
- Left
- Flight hours
- 1,661 total · 35 in this make and model · 35 in the last 30 days · 5 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 300° at 10 knots, gusting 20
- Visibility
- 10 statute miles
- Lowest ceiling
- 7,000 ft overcast
- Temperature
- 59 °F, dew point 34 °F
- Altimeter
- 29.78 inHg
- Observed at
- KBTM, 60 nm away
Docket · 3
The files NTSB released with the investigation on July 25, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.8 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.