Pilot Debrief

MOULTON HOWARD WELLS ULTRA-PUP near Lyman, ME — 2012-10-06

Final reportERA13CA010
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Date
2012-10-06
Location
Lyman, ME, USA
Aircraft
MOULTON HOWARD WELLS ULTRA-PUP
Registration
N3073X
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Cruise

Probable cause

The accumulation of ice in the automotive engine’s carburetor, which resulted in a loss of engine power.

NTSB narrative

About 20 minutes into the cross-country flight, the pilot of the experimental amateur-built airplane detected a vibration of the airplane’s engine that “didn’t sound good,” and noticed a drop in the rpm of the automotive-conversion engine. He immediately applied carburetor heat, but the engine continued to lose power until the airplane could no longer maintain altitude and began to descend from its cruise altitude of 1,500 feet above ground level. The pilot performed a forced landing into the trees below, substantially damaging the airplane’s fuselage, wings, and empennage. Postaccident examination of the airplane, its engine, and its fuel system revealed no evidence of preimpact malfunctions or anomalies that would have precluded normal operation. Although the fuel system was compromised by impact damage, the fuel that remained in the system was absent of contamination. According to a carburetor icing probability chart published by the Federal Aviation Administration, the temperature and dew point reported at an airport located about 6 nautical miles from the accident site were conducive to “serious icing at cruise power.”

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have checked carburetor heat system adequacy before flight.

NTSB coding

Evidence available

  • Photos
  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

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