- Date
- September 24, 2015, 13:00 local (21:00 UTC)
- Place
- Arctic Village, AK
- Injuries
- 1 minor, 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Takeoff
- Aircraft
- N2528CCessna 170B
- Defining event
- Takeoff: Aerodynamic stall/spin
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 3, 2015
- Report
- Approved by Office Director
- NTSB office
- General Aviation Accidents
- Parties
- FAA Fairbanks FSDO
- FAA report
- 20150924016519A
- Case key
- 92082
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 exceeded the critical angle of attack during takeoff, which resulted in an aerodynamic stall and a collision with terrain.
Findings · 2
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 after taking off from a frozen gravel bar by a river in remote wilderness, the airplane stalled. The left main landing gear struck the edge of the cut bank and the left wing impacted the ground. The fuselage then impacted the top of the bank and spun counterclockwise. The pilot stated that the left wing was separated from the fuselage and the fuselage had sustained substantial damage. The pilot reported there were no pre-impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
Factual narrative
The pilot reported that after taking off from a frozen gravel bar by a river in remote wilderness, the airplane stalled. The left main landing gear struck the edge of the cut bank and the left wing impacted the ground. The fuselage then impacted the top of the bank and spun counterclockwise. The pilot stated that the left wing was separated from the fuselage and the fuselage had sustained substantial damage. The pilot reported there were no pre-impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The pilot reported as a safety recommendation, "I would take off empty or with minimal known weight to ensure that the aircraft would perform as planned. I could then land to reload, or if partially loaded, fly to another gravel bar that was longer, and stage from there, returning to the point of origin empty, and then continue to shuttle gear and people. That first flight would have been better planned without another person on board, not just due to weight, but due to risk to that person." ADDITIONAL INFORMATION Alaska Off Airport Flight Operations The Alaskan Aviation Safety Foundation has published a safety briefing Off Airport Landings. This safety briefing discusses off airport takeoff and landing operations. This safety briefing states in part; When flying very low and slow on takeoff or landing approach, do not fly over an abrupt drop-off such as a cut bank or steep lake shore. You can abruptly lose ground effect and begin to settle. This safety briefing also lists considerations when selecting off airport takeoff and landing sites and states in part; Airplane load: Obviously, ever gram counts. Density altitude: You don't have to go into the mountains to get a change in density altitude. Ground drag: A thawed gravel bar, even a dry one, presents considerably more drag than a frozen one. Departure obstacles: An obvious thing, but if you've been flying off river bars in ground effect, it's easy to underestimate the additional space needed to clear a 15 foot obstacle.
Aircraft
- Registration
- N2528C
- Reported as
- Cessna 170B (UNDESIGNAT)
- Category
- Airplane
- Serial number
- 26172
- Built
- 1954
- Airframe hours
- 2,653
- Engine
- Lycoming O-320-D1A, 160 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · January 7, 2015
- Departed
- FAI · Fairbanks, AK
- Destination
- FAI · Fairbanks, AK
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
- 57
- Injuries
- Minor
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Without waivers/limitations
- Last flight review
- July 8, 2014
- Seat
- Left
- Restraint
- 4-point
- Flight hours
- 355 total · 110 in this make and model · 316 as pilot in command
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 60° at 5 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- 1,700 ft overcast
- Temperature
- 21 °F, dew point 12 °F
- Altimeter
- 29.84 inHg
- Observed at
- PARC, 78 nm away
Docket · 2
The files NTSB released with the investigation on November 10, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.2 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.