Casualties unknown

1992-04-05: Cessna 177RG (N52638) — Gjovaag, Inghard J. — Scappoose, OR

Scappoose, OR, US

On April 5, 1992, a Cessna 177RG (registration N52638) operated by Gjovaag, Inghard J. was involved in an aviation accident near Scappoose, OR. Investigators recorded the probable cause as: The pilot's inability to maintain control during a forced landing due to an unexplained loss of engine power while descending in IMC. 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 pilot experienced an unexplained loss of engine power while descending in instrument meteorological conditions on an IFR flight, resulting in a forced landing attempt.

What happened

The pilot was operating under instrument flight rules (IFR) and was in the process of descending through instrument meteorological conditions (IMC) when the aircraft experienced a sudden loss of engine power. With no immediate options for returning to the departure airport or diverting to an alternate field, the pilot initiated a forced landing procedure.

During the attempt to land on a road, the aircraft impacted obstacles. The impact resulted in significant damage to the airframe. The pilot survived the incident, though specific injury details were not provided in the source record.

The investigation

Following the accident, investigators examined the engine and associated systems to determine the cause of the power loss. A critical finding was that there was no evidence of any mechanical malfunction or failure that would have caused the sudden loss of power during flight.

To further verify the integrity of the propulsion system, the engine was tested after the accident. The investigation found that the engine ran normally after the incident, indicating that the power loss was not due to a persistent mechanical defect within the engine itself.

Findings

The primary factor in this event was the unexplained loss of engine power during descent. Contributing factors included the weather conditions (IMC) which limited visibility and options for recovery, and the terrain/obstacles present near the intended landing site on the road.

The investigation concluded that since the engine operated normally post-accident, the cause was likely transient or related to fuel supply/intake rather than internal mechanical failure. However, without further data, the specific trigger remains unconfirmed beyond the observation of normal engine operation after the event.

Probable cause

The pilot's inability to maintain control during a forced landing due to an unexplained loss of engine power while descending in IMC.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X14519. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.