Pilot Debrief

PIPER PA-25-235 near Westerly, RI — 2009-07-04

Final reportERA09LA380
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Date
2009-07-04
Location
Westerly, RI, USA
Airport
WST
Aircraft
PIPER PA-25-235
Registration
N4898Y
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Descent

Probable cause

The pilot's failure to use carburetor heat resulting in a complete loss of engine power due to carburetor icing.

Contributing factors

Findings Aircraft Fuel quantity indicator - Damaged/degraded Aircraft Intake anti-ice, deice - Not used/operated Environmental issues Conducive to carburetor icing - Contributed to outcome

NTSB narrative

The commercially-rated pilot flew the accident airplane for almost 4 hours on a banner-tow flight earlier on the day of the accident. He landed, refueled the airplane, detected some water in the fuel strainer sample, and sampled that until no more water was obtained. He then departed on the accident flight, which was another banner-tow mission. That flight lasted about 3 hours. When the airplane was inbound to, and approximately 2 miles from the home airport, and at an altitude of approximately 1,000 feet, the engine lost all power. The pilot described the power loss as "smooth," with no roughness or stumbling. He initially diverted for a golf course, enriched the mixture, applied carburetor heat, and attempted to re-start the engine. The engine did not re-start, and the pilot jettisoned the banner and steered for another emergency landing site that was closer. The airplane was substantially damaged during the landing and rollout. The airplane was equipped with a main fuel tank and an auxiliary fuel tank. Fuel could only be supplied to the engine from the main tank, and a manually-controlled pump was used to pump fuel from the auxiliary tank to the main tank. Only the main tank was equipped with a fuel gauge, and due to the opacity of its enclosure, the gauge was unreadable. Due to conflicting witness reports, the amount and distribution of the fuel on board at the time of the power loss and accident was not able to be definitively determined. Federal Aviation Administration (FAA) inspectors found an unspecified amount of fuel in the carburetor bowl, and obtained a total of about 1/2 ounce of water from the carburetor bowl and the fuel strainer. They did not observe any mechanical conditions or problems that could have resulted in the engine power loss. The inspectors added fuel to the airplane, and the engine started and ran normally. According to carburetor ice envelope charts, the temperature and dew point values for the approximate time and location of the power loss were such that the airplane was operating in the region denoted as "Serious Icing at Glide Power."

Analysis

Primary failure mode
Fuel management
First missed decision gate
Pilot could have ensured no water in fuel before departure.

NTSB coding

Evidence available

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

Docket documents11

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