ANC12CA072

NTSB accident investigation · Piper PA-12 · Quinhagak, AK · July 6, 2012

Accident · No injuriesData collectionFinal report
Date
July 6, 2012, 09:05 local (17:05 UTC)
Place
Quinhagak, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N7779HPiper PA-12
Defining event
Initial climb: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed · report November 26, 2012
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA Anchorage FSDO
FAA report
20120706013499A
Case key
84257

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to use continuous carburetor heat while operating in conditions conducive to carburetor icing, which resulted in the development of carburetor ice and a subsequent partial loss of engine power.

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.

Use of equip/info: use of equip/systemPersonnel issues › Task performance · PilotPiper PA-12: 10 casesAll aircraft: 1,391 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Decision related to conditionPiper PA-12: 6 casesAll aircraft: 435 casesProbable cause

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 stated that he was landing his tailwheel-equipped airplane at an off-airport site. During the landing roll, he aborted the landing but was unable to clear terrain at the departure end of the site, about 400 feet from where he aborted the landing. The airplane impacted the ground, sustaining substantial damage to both wings and the fuselage. The pilot indicated that there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation. In his written statement to the NTSB, the pilot stated that the engine may not have been producing full power but, if so, he did not realize it or take any corrective action, such as applying carburetor heat. In a telephone conversation, he said that he had been flying at reduced power settings during his reconnaissance passes, with occasional use of carburetor heat to clear any possible carburetor ice. He also stated that his normal before-landing procedure is to turn off the carburetor heat on short final. According to a carburetor icing probability chart, an airplane operating in the ambient conditions at the accident site, as reported by the pilot, could expect a serious risk of carburetor icing while at cruise power.

Factual narrative

In a telephone conversation with the National Transportations Safety Board (NTSB) investigator-in-charge just after the accident, the pilot stated that he was landing his tailwheel-equipped airplane at an off-airport site. During the landing roll he aborted the landing, but he was unable to clear terrain at the departure end of the site, about 400 feet from where he aborted the landing. The airplane impacted terrain, sustaining substantial damage to both wings, and the fuselage. The pilot indicated that there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation. In his written statement to the NTSB, the pilot stated that the engine may not have been producing full power, but he did not realize it, or take any corrective action for application of carburetor heat. In a telephone conversation on August 23, he said had been flying at reduced power settings during his reconnaissance passes, with occasional use of carburetor heat to clear any possible carburetor ice. He also stated that his normal before-landing procedure is to turn off the carburetor heat on short final. According to a carburetor icing probability chart, an airplane operating in the ambient conditions at the accident site, reported by the pilot, could expect serious carburetor icing while at cruise power.

Aircraft

Registration
N7779H
Reported as
Piper PA-12
Category
Airplane
Serial number
12-677
Airframe hours
4,390
Engine
Lycoming O-320 SERIES, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 28, 2012 · 9 hours before
Departed
Togiak, AK
Destination
Quinhagak, 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
56
Injuries
None
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Last flight review
September 23, 2010
Seat
Front
Flight hours
6,304 total · 3,450 in this make and model

Weather

Conditions
Visual (VMC) · Day
Visibility
10 statute miles
Lowest ceiling
1,200 ft broken
Temperature
45 °F, dew point 43 °F

Docket · 3

The files NTSB released with the investigation on October 5, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 697 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.