- Date
- December 4, 2010, 14:00 local (22:00 UTC)
- Place
- Pullman, WA
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N4100ZPiper PA-18-150
- Defining event
- Maneuvering-low-alt flying: Fuel related
- Weather
- Visual (VMC) · Day
- Status
- Completed · report April 12, 2011
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Spokane FSDO
- FAA report
- 20101204052369A
- Case key
- 77936
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 delayed application of carburetor heat while maneuvering, which resulted in a partial loss of engine power.
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 was maneuvering the airplane at a low altitude over open, snow-covered terrain, and noticed that the engine was beginning to lose power and running roughly. The airplane was starting to lose altitude and in response, he applied the carburetor heat and added full engine power. Just as the engine started to regain power, the main landing gear broke through the crusty top layer of the snow, slowing the airplane. The propeller contacted the snow and the pilot decreased the engine power and attempted to transition to a landing. The airplane nosed over inverted, resulting in substantial damage to the vertical stabilizer and both left wing lift struts. According to the pilot, with the exception of the accumulation of carburetor ice, there were no mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.
Factual narrative
The pilot, who was chasing coyotes at low level over open snow-covered terrain, noticed that the airplane's engine was beginning to lose power and run rough, and that the airplane was starting to lose altitude. He therefore applied carburetor heat and full power, but just as the engine started to regain power, the airplane's main wheels broke through the crusty top layer of the snow. The airplane then began to slow, and when its propeller contacted the snow, the pilot pulled the power back and attempted to transition to a landing. Although the pilot had the control stick all the way back, the airplane nosed over onto its back, resulting in damage to the vertical stabilizer and the bending of both left wing lift struts. According to the pilot, except for the accumulation of carburetor ice, there were no problems with the engine.
Aircraft
- Registration
- N4100Z
- Reported as
- Piper PA-18-150
- Category
- Airplane
- Serial number
- 18-8114
- Engine
- Lycoming O-320 SERIES, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Keith M. Kopf
- Registered owner
- Mountain Escape LLC
- Airworthiness certificate
- Standard, Normal
- Departed
- KPUW · Pullman, WA
- Destination
- KPUW · Pullman, WA
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
- 55
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land, Single-engine sea
- Medical
- Class 3, Without waivers/limitations
- Flight hours
- 1,315 total · 760 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 80° at 10 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 30 °F
Docket · 2
The files NTSB released with the investigation on December 20, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 504 KB 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.
Other investigations on N4100Z · 1
Matched to the same aircraft by N-number and date.