Casualties unknown

Engine Power Loss and Emergency Landing on Gravel Bar Leads to Overturn (N891A)

65 Mi.ene OF MC, AK, US

On July 17, 1982, a Piper PA-22 (registration N891A) operated by Paul Moore & Dave Armstrong was involved in an aviation accident near 65 Mi.ene OF MC, AK. 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 2026-06-10Data APIEditorial standards

During flight, a progressive loss of power prompted an emergency landing on a gravel bar. The aircraft struck a log and a bank, flipping onto its back. Investigation revealed a failed exhaust valve adjustment bolt in the No. 3 rocker arm, possibly due to overtightening.

Incident Summary

During flight, the pilot noticed a progressive loss of engine power. He elected to perform an emergency landing on a gravel bar. During the landing roll, the aircraft traversed a shallow slough, where the left main landing gear struck a log. Subsequently, the nose gear impacted a bank at the edge of the slough, causing the aircraft to flip onto its back. The engine ceased operating when the aircraft inverted.

Examination Findings

An examination of the engine disclosed that the No. 3 rocker arm exhaust valve adjustment bolt had failed and was found loose inside the valve cover. There was evidence that the bolt may have been overtightened. The specified torque for the bolt was 450 inch-pounds. Inspection of the other similar bolts revealed that their torque values ranged from 150 to 450 inch-pounds. The engine had accumulated a total of 3.7 hours of operation since a top overhaul.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20020917X02652. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.