Casualties unknown

Electrical Fire Prompts Emergency Descent and Gear Collapse (N699T)

Concord, AR, US

On August 18, 1989, a Beech V35B (registration N699T) operated by Graebner, Walter D. was involved in an aviation accident near Concord, AR. Investigators recorded the probable cause as: The owner improperly installed an alternator wiring harness, which rubbed on the noise suppressor; after it rubbed through the insulation, an electrical fire erupted. 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

While climbing through 9,000 ft MSL, the pilot smelled an electrical odor. Dense smoke filled the cabin, leading to an emergency descent. The landing gear collapsed on rolling terrain, damaging the aircraft.

Incident Overview

A pilot/owner reported that during a climb through 9,000 ft MSL en route to 10,000 ft MSL on an IFR flight plan, an electrical odor was detected. The cabin rapidly filled with dense smoke, prompting the pilot to shut off all electrical switches and initiate an emergency descent.

Emergency Descent and Landing

During the descent, the smoke substantially cleared from the cabin. The landing gear was extended using emergency procedures. Upon landing on rolling terrain, the gear collapsed, resulting in damage to the aircraft. No fire continued on the ground after landing.

Post-Accident Investigation

A post-accident investigation revealed that the owner had improperly installed an alternator wiring harness. The harness rubbed against the noise suppressor, wearing through the insulation. This allowed an electrical fire to erupt.

Probable cause

The owner improperly installed an alternator wiring harness, which rubbed on the noise suppressor; after it rubbed through the insulation, an electrical fire erupted.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X29218. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.