Casualties unknown

1990-11-15: Bell 47-G3-B (N2921W) — Firefly, Inc. — Nantucket, MA

Nantucket, MA, US

On November 15, 1990, a Bell 47-G3-B (registration N2921W) operated by Firefly, Inc. was involved in an aviation accident near Nantucket, MA. Investigators recorded the probable cause as: The pilot's failure to anticipate and prevent carburetor ice, which resulted in a loss of engine power and a subsequent hard landing. 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 experienced a power loss from carburetor ice during a positioning flight, resulting in a hard landing and post-crash fire.

What happened

The pilot was conducting a positioning flight at an altitude of 1000 feet above ground level when the aircraft suddenly lost power. The loss of engine power was attributed to carburetor ice formation. In response to the emergency, the pilot initiated an autorotation into a large open area nearby. The landing was executed with significant force, resulting in a hard impact.

Upon impact, the main rotor struck the tail boom of the helicopter. This collision caused a rupture in a hydraulic line, which subsequently ignited a small post-crash fire. Despite the structural damage and fire, the pilot managed to evacuate the scene.

The investigation

Following the accident, investigators examined the aircraft to determine the extent of the damage and the cause of the power loss. A test run of the engine was conducted after the accident to verify its mechanical integrity. The test results indicated that the engine operated satisfactorily, suggesting that the power loss was not due to an internal mechanical failure but rather environmental factors.

Findings

The investigation concluded that the primary factor leading to the accident was the formation of carburetor ice, which caused a sudden loss of engine power. The hard landing and subsequent damage were direct consequences of the emergency maneuver required to avoid a more severe outcome in populated areas.

Probable cause

The pilot's failure to anticipate and prevent carburetor ice, which resulted in a loss of engine power and a subsequent hard landing.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X24670. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.