Casualties unknown

Partial Loss of Engine Power Results in Emergency Landing and Gear Collapse (N2033N)

Tetonia, ID, US

On June 21, 1999, a Weatherly 620B (registration N2033N) was involved in an aviation accident near Tetonia, ID. Investigators recorded the probable cause as: The right magneto gear drive shaft sheared, leading to partial loss of engine power. 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

After leveling off at 200 feet AGL, an aircraft experienced a partial loss of engine power. The pilot conducted an emergency landing in rough terrain, where the right wing struck the ground and the main landing gear collapsed. Investigation identified a sheared right magneto gear drive shaft.

Accident Overview

Shortly after the pilot leveled the aircraft at 200 feet above ground level (AGL), the engine experienced a significant partial loss of power. The pilot determined that the aircraft could not maintain flight and initiated an emergency landing on rough, uneven terrain. During the landing, the right wing contacted the terrain, causing the aircraft to spin around. The main landing gear collapsed during this sequence of events.

Investigation Findings

The subsequent investigation focused on the engine and related systems. No evidence of any malfunction or anomaly other than the identified failure was found. The examination revealed that the right magneto gear drive shaft had sheared. This failure was determined to be the direct cause of the partial loss of engine power.

Probable cause

The right magneto gear drive shaft sheared, leading to partial loss of engine power.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X19119. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.