Casualties unknown

Aircraft Crash in Hilly Terrain; Pilot Missing for Two Days Before Wreckage Found (N6599L)

Pleasanton, CA, US

On July 31, 1983, a Cessna 152 (registration N6599L) operated by Fred Nediffer was involved in an aviation accident near Pleasanton, CA. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

A single-pilot aircraft crashed in a steep nose-down attitude in hilly terrain, with debris scattered 100 ft. The pilot had been missing for two days; his car was found at Hayward Air Terminal, CA. No discrepancies in airframe or engine were found.

Overview

An aircraft crashed in a steep nose-down attitude in hilly terrain, scattering debris over an area of about 100 feet. The wreckage did not travel after initial impact. The fuel tanks were ruptured, and no fuel remained at the scene. Deputies reported no odor of fuel upon arrival. The wreckage was not located for approximately two days after the accident.

Accident Details

The pilot's wife last saw him on July 30 at 2300 hours PDT. He reportedly left home that night or early the next morning. When he did not return on July 31, his wife reported him missing. His car was later found at Hayward Air Terminal, California. No witnesses to the accident have been identified. The wreckage was eventually discovered by a rancher who was checking cattle on his property.

Investigation Findings

During the investigation, no discrepancies were uncovered in the airframe or engine. An autopsy and toxicological tests revealed nothing out of the ordinary. The pilot's wife stated that her husband had been depressed due to business issues and had threatened suicide in the past, but she did not believe he would take any action in that regard. However, no official determination was made regarding the cause of the accident.

Additional Context

The aircraft was missing for two days before being found. The pilot had been depressed, according to his wife, but toxicology and autopsy results did not indicate any unusual findings.

All Cessna 152 accidents →

Frequently asked questions

What happened in the 31 Jul 1983 Cessna 152 accident near Pleasanton, CA?

A single-pilot aircraft crashed in a steep nose-down attitude in hilly terrain, with debris scattered 100 ft. The pilot had been missing for two days; his car was found at Hayward Air Terminal, CA. No discrepancies in airframe or engine were found.

What aircraft was involved and where did it happen?

The accident on 31 Jul 1983 involved a Cessna 152, registration N6599L, operated by Fred Nediffer, at Pleasanton, CA.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X43782. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.