Aviation Accident Summaries

Aviation Accident Summary ANC93IA183

ANCHORAGE, AK, USA

Aircraft #1

N9211T

CESSNA 180C

Analysis

THE FUEL HOSE BETWEEN THE FUEL FILTER AND THE CARBURETOR WAS FRAYED AND LEAKED FUEL ONTO THE BOTTOM OF THE ENGINE COWL ADJACENT TO THE CARBURETOR INDUCTION BOX. ADDITIONALLY, INVESTIGATORS FOUND THE AIRPLANE WING AND FLOAT STRUCTURE COMPONENTS TO BE IRREGULAR AND BOGUS FROM RECENT REBUILD PROCESS.

Factual Information

On September 22, 1993, at 1120 Alaska daylight time, a float equipped Cessna 180C airplane, N9211T, caught fire while taxiing for takeoff at Finger 3 of the Lake Hood Seaplane operating area, at Anchorage International Airport. The flight was departing for Kodiak, Alaska, on a VFR flight plan in visual meteorological conditions under 14 CFR Part 91 for personal reasons. The private pilot and a passenger escaped without injury and the airplane sustained minor damage. The pilot told NTSB and FAA investigators that he "was taxiing out to go to Kodiak." He said that he remembered "pumping the throttle, and after I got it going again (restarting the engine), I saw smoke and shut it down." The pilot said that he and the passenger extinguished the fire by pouring boots full of water on the cowl. The aircraft was secured at its moorings when NTSB and FAA investigators arrived. During the examination of the scorched aircraft, investigators found the right wing and the left wing to be mismatched, in that the fuel tank installations may indicate replacements of parts from different aircraft. Additionally the float plane installation examined by the FAA, was found to have homemade (bogus parts) and non-standard application. An examination of the engine compartment revealed that a shielded fuel hose between the fuel filter and the carburetor showed abraded fraying of the metal outer cover. When the fuel selector was returned to "on," aviation fuel leaked from the line onto the inner bottom of the engine cowl adjacent to the carburetor induction box. Fire scorching was visible in the area of that line and the firewall behind that point. No scorching was found inside the induction box, however a film of soot was seen in the induction throat. The pilot said that he had purchased the airplane "as a wreck" and "George Grant of Merrill Field had completely rebuilt it, just 3 months ago." The pilot said that the airplane's log books were in the possession of Mr. Grant. The airplane had mismatched wings and other components installed by this FAA A&P mechanic that did not conform to the certificate specifications of the Cessna 180 aircraft. Following this investigation, the FAA issued a request for an Emergency Airworthiness Directive to request a "Conformity Inspection" on all future aircraft modified by this mechanic.

Probable Cause and Findings

A FRAYED FUEL HOSE.

 

Source: NTSB Aviation Accident Database

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