Casualties unknown

1983-04-02: Piper PA-12 (N2826M) — Glennallen, AK

Glennallen, AK, US

On April 2, 1983, a Piper PA-12 (registration N2826M) was involved in an aviation accident near Glennallen, AK. Investigators recorded the probable cause as: Interference of the elevator bellcrank by a whisk broom in the baggage compartment, due to inadequate protection of the control mechanism. 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

An aircraft crashed after takeoff due to a whisk broom interfering with the elevator bellcrank, which lacked proper protection in a modified baggage compartment.

What happened

Witnesses observed the aircraft shortly after departure, flying near a cabin at an altitude of approximately 200 feet. The pilot signaled by rocking the wings before initiating a gradual climb. This climb steepened significantly until witnesses could see the entire top surface of the aircraft. The aircraft then nosed over and executed one and a half to two and a half turns before crashing into the ground.

The investigation

The investigation found no specific pre-impact mechanical malfunction or failure that directly caused the crash. However, inspectors noted that the aircraft had undergone three major modifications, two of which were approved under Supplemental Type Certificates (STCs). A modified elevator bellcrank had been installed as part of these changes.

Crucially, there was no floor or protective covering installed over this bellcrank. The only barrier protecting the mechanism from items placed in the baggage compartment was a piece of canvas. This canvas did not extend to the sides, top, or bottom of the fuselage. Instead, it was held in place by a two-to-three-inch cap laced with string. A whisk broom was found in close proximity to the elevator bellcrank after the accident.

Findings

The primary finding was that the whisk broom likely interfered with the operation of the elevator bellcrank. The inadequate protection provided by the canvas barrier allowed foreign objects in the baggage compartment to reach critical flight control components. This interference led to a loss of control during the climb phase.

Safety message

Aviation maintenance and modification practices must ensure that all flight control mechanisms are fully protected from foreign object debris (FOD). Baggage compartments containing items that could shift must have secure, full-coverage barriers to prevent contact with critical systems.

Probable cause

Interference of the elevator bellcrank by a whisk broom in the baggage compartment, due to inadequate protection of the control mechanism.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X42571. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.