Casualties unknown

1999-05-08: Aeronca 15AC (N1315H) — Pedro Bay, AK

Pedro Bay, AK, US

On May 8, 1999, an Aeronca 15AC (registration N1315H) was involved in an aviation accident near Pedro Bay, AK. Investigators recorded the probable cause as: The vibration shook loose the left engine exhaust pipe which then directed the exhaust onto the fuel line to the carburetor which caused the fire. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A commercial pilot reported smoke and rough engine followed by flames from under floorboards. Ditching short of beach resulted in nose-over. Investigation found cylinder separation and fuel line fire caused by exhaust pipe vibration.

Accident Overview

The accident occurred during a climb through 7,000 feet mean sea level when the pilot of a single-engine airplane encountered smoke and engine roughness. An emergency descent was initiated, during which smoke and flames were observed emanating from beneath the floorboards near the rudder pedals. The pilot subsequently ditched the airplane in shallow ocean water just short of a beach. Upon touchdown, the airplane nosed over.

Pilot Report

The pilot stated, in part: "My legs were on fire and I just wanted to put the fire out, and get the airplane on the ground." The pilot reported that after smelling smoke, the engine began running rough, prompting the emergency descent. The flames visible under the floorboards intensified during the descent.

Post-Accident Examination

An FAA airworthiness inspector examined the wreckage at the scene. Inspection of the engine revealed that the top portion of the number three cylinder had separated between the cylinder barrel and the cylinder head. The main fuel supply line was found burned through and disconnected from the carburetor inlet fitting. The inspector's written statement noted that "the vibration shook loose the left engine exhaust pipe which then directed the exhaust onto the fuel line to the carburetor which caused the fire."

Probable Cause

The FAA inspector identified the cause as vibration-induced loosening of the left engine exhaust pipe, which directed exhaust onto the fuel line, resulting in a fire.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X18674. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.