Casualties unknown

1992-07-01: Grumman G-164A (N8636H) — San Joaquin Helicopters — Tulare, CA

Tulare, CA, US

On July 1, 1992, a Grumman G-164A (registration N8636H) operated by San Joaquin Helicopters was involved in an aviation accident near Tulare, CA. Investigators recorded the probable cause as: AN INFLIGHT HOPPER COMPARTMENT FIRE DUE TO THE INCOMPATIBILITY OF THE CHEMICAL LOADS, AND, THE FAILURE OF THE OPERATOR FOLLOW THE CAUTIONARY DIRECTIVES OF THE CHEMICAL MANUFACTURER. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 5 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

Witnesses observed an aircraft trailing spray or smoke at low altitude before it changed course, appeared to attempt a landing on a road, struck power lines, and crashed. A post-crash fire consumed the aircraft.

Incident Description

Multiple witnesses observed the aircraft as it approached the accident site. The aircraft was at a low altitude and trailing a heavy volume of spray or smoke. Suddenly, the aircraft changed its course, and the pilot appeared to be attempting to land on a road. Some witnesses reported seeing flames emanating from the engine compartment area, while others indicated that the engine burst into flames while the aircraft was still in flight. As the aircraft turned toward the road, it struck power lines and subsequently crashed. A post-crash fire consumed the aircraft.

Examination of Aircraft Components

Following the accident, an examination of the engine was conducted. The engine had separated from the fuselage during the impact. The examination found no evidence of a fire in the engine, and all hoses were observed to be intact. The wooden hopper door also separated from the fuselage and was discovered along the flight path. The interior side of the hopper door was heavily charred, while the exterior side showed no evidence of fire.

Historical Loading Information

Records from the operation indicated that the aircraft had been loaded with potassium permanganate after sulfur had been transported on a previous flight. The manufacturer of the chemical reported that potassium permanganate is an oxidizer that is reactive with even small amounts of sulfur.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X15176. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.