Casualties unknown

1987-07-08: Bell 47D1 (N908B) — John L. Lanier — Huntsville, AL

Huntsville, AL, US

On July 8, 1987, a Bell 47D1 (registration N908B) operated by John L. Lanier was involved in an aviation accident near Huntsville, AL. Investigators recorded the probable cause as: The pilot's failure to maintain sufficient airspeed to ensure effective translational lift and failure to apply additional power in time to prevent the helicopter from settling into terrain. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 1 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

An aerial application helicopter settled into terrain while maneuvering to avoid powerlines; the pilot failed to maintain airspeed and apply power in time, causing the helicopter to nose over after rotor blades struck the ground.

Accident Description

The accident occurred during an aerial application flight that was dispensing insecticides over a cotton field. While the helicopter was maneuvering to avoid powerlines during the procedure turnaround following an upwind swath run, the pilot failed to maintain sufficient airspeed.

Sequence of Events

Due to the insufficient airspeed, the helicopter began to settle, as translational lift became ineffective. The pilot did not apply additional power in time to arrest the descent. Consequently, the helicopter settled into the terrain. Upon ground contact, the rotor blades struck the ground, causing the helicopter to nose over.

Findings

The investigation identified that the pilot's failure to maintain airspeed and apply power resulted in the loss of effective translational lift and subsequent settling. The maneuver to avoid powerlines during the turnaround was a factor in the sequence, but the direct cause was the pilot's actions regarding airspeed and power management.

Probable cause

The pilot's failure to maintain sufficient airspeed to ensure effective translational lift and failure to apply additional power in time to prevent the helicopter from settling into terrain.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X31395. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.