Pilot Debrief

OTTERBACK Lightning near Woodland, WA — 2019-05-01

Final reportWPR19LA132
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Date
2019-05-01
Location
Woodland, WA, USA
Airport
W27
Aircraft
OTTERBACK Lightning
Registration
N106AL
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

A complete loss of engine power due to carburetor icing.

NTSB narrative

The pilot reported that after an uneventful flight in an experimental airplane he set up for landing. At about 1,200 feet he reduced the throttle to idle, turned on the carburetor heat, and entered the traffic pattern. After turning final, when the pilot began to reach for the throttle, the propeller stopped spinning. The engine had lost complete power, with no engine roughness or abnormal noises. Since the airplane was about 50 ft above the ground, the pilot continued to land onto the runway. The airplane bounced and when it touched back down, the airplane departed the left side of the runway. The pilot redirected the airplane back toward the runway surface, but the nose gear collapsed on the rough grass. The nearest weather reporting station indicated temperature 13°C, dewpoint 4°C. Review of the Carburetor Icing Probability Chart revealed that, given the temperature and dewpoint, the conditions were on the line between serious icing at glide power and serious icing at cruise power. During a telephone conversation the pilot reported that the carburetor heat system takes hot air from near the muffler to keep the carburetor from icing up. It is likely that the carburetor accumulated ice while in cruise flight and the carburetor heat, when applied when the pilot reduced the throttle to idle, was not sufficient to remove the carburetor ice which resulted in a loss of engine power.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have avoided carburetor icing by not using idle power during approach.

NTSB coding

Evidence available

  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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