Casualties unknown

1988-07-04: Cessna 320D (N9HS) — Mammoth Lakes, CA

Mammoth Lakes, CA, US

On July 4, 1988, a Cessna 320D (registration N9HS) was involved in an aviation accident near Mammoth Lakes, CA. 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 executing a crosswind departure from Runway 27 stalled his airplane while turning near higher terrain, crashing into the median of Highway 395. The airplane was overweight and near its aft CG limit; the pilot had disregarded medical advice to stop flying.

Accident Sequence

The pilot departed Runway 27 with a left crosswind, heading south toward higher terrain. The airplane followed a slower single-engine aircraft that had departed before it. According to ground witnesses, as the airplane approached the higher terrain, it entered a left banking turn. During the turn, the wings oscillated rapidly, and the airplane subsequently stalled. It crashed into the center divider of California State Highway 395, which runs adjacent to and parallel with the east-west runway.

Examination Findings

A post-accident examination of the airframe and engine revealed no evidence of any preexisting malfunctions or failures. However, the investigation determined that the airplane had exceeded its maximum gross takeoff weight and was operating near its aft center of gravity limits.

Pilot Medical Background

Prior to the accident, the pilot had complained to his doctor about episodes of forgetfulness and confusion. The doctor recommended that the pilot cease any flying activities until the medical condition could be diagnosed and treated. The pilot did not follow this advice.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X26258. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.