Casualties unknown

1992-09-24: Cessna 320B (N9811L) — Ehrstrom, William H. — Lowell, ID

Lowell, ID, US

On September 24, 1992, a Cessna 320B (registration N9811L) operated by Ehrstrom, William H. was involved in an aviation accident near Lowell, ID. Investigators recorded the probable cause as: RAM INDUCTION AIR STARVATION OF BOTH ENGINES AND INABILITY OF THE PILOT IN COMMAND TO CLEAR TREES DURING THE FORCED LANDING. FACTORS CONTRIBUTING TO THE ACCIDENT WERE LOW CEILINGS AND TREES. 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

During cruise at 14,000 feet in snow, an aircraft lost power in both engines. Descending to 3,000 feet restored power. The pilot performed a precautionary landing on an abandoned airstrip, striking small trees.

Summary

An aircraft experienced an abrupt loss of power in both engines while cruising at 14,000 feet. The incident occurred during flight in snow with an outside air temperature of approximately 0 degrees Fahrenheit. The aircraft descended to 3,000 feet MSL, during which engine power was regained. Upon breaking out of an undercast with limited vertical and lateral clearance surrounded by upsloping terrain, the pilot elected to execute a precautionary landing at a nearby abandoned airstrip. During the landing roll, the aircraft impacted small trees that had grown in the landing area.

Event Details

The aircraft was established in cruise at 14,000 feet with 21 inches of manifold pressure when both engines abruptly lost power. The exterior conditions included snowfall and an outside air temperature of about 0 degrees Fahrenheit. The descent to 3,000 feet MSL allowed the engines to regain power. The pilot then encountered a break in the cloud cover providing approximately 800 feet of vertical clearance and 1 square mile of lateral airspace. Given the upsloping terrain surrounding the aircraft, the pilot decided to land on an abandoned airstrip nearby. During the landing roll, the aircraft struck small trees that had grown in the landing area, causing damage.

Post-Crash Investigation

A post-crash investigation revealed moisture within both air induction systems. Examination determined that both alternate air systems were capable of proper operation. Additionally, uncontaminated fuel was found within all four fuel tanks, indicating that fuel quality was not a factor in the power loss.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X15786. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.