Casualties unknown

Aircraft Accident After Throttle Cable Detachment During Descent (N6248R)

Hyampom, CA, US

On July 12, 1998, a Piper PA-18-150 (registration N6248R) was involved in an aviation accident near Hyampom, CA. Investigators recorded the probable cause as: Inadequate annual inspection that resulted in a partial loss of engine power due to a missing bolt, nut, and cotter pin from the throttle/carburetor assembly. 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

A pilot reported a throttle cable detachment due to missing hardware after an emergency landing on a gravel bar; the aircraft inverted.

Accident Overview

Following takeoff, the airplane climbed over mountainous terrain. After clearing the terrain, the pilot reduced power and began a descent into an open valley. At approximately 1,800 feet above ground level, the pilot advanced the throttle but did not receive an increase in engine power. Declaring an emergency, the pilot attempted to land on a narrow gravel bar adjacent to a river.

Landing and Post-Accident Condition

The main landing gear skimmed over the water and then contacted the gravel bar's edge. The left main gear sank into the soft gravel at the water's edge, causing the aircraft to come to rest inverted on the gravel bar. The pilot stated that an annual inspection had been performed 11 days prior to the accident, and the airplane had accumulated only 3 flight hours since that inspection.

Throttle Cable Inspection

Following the accident, the pilot inspected the throttle cable assembly and noted that it had become detached from the carburetor throttle arm due to a missing bolt, nut, and cotter pin. The Federal Aviation Administration (FAA) was unable to verify the absence of these components because the pilot had repaired the aircraft and ferried it to another location before an official inspection could be conducted.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X10630. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.