FlightFinder
Check my flight
Casualties unknown

Helicopter Collides with Unmarked Power Line During Wildlife Survey (N771GM)

Coolidge Dam, AZ, US

On January 4, 1994, a Bell 206B (registration N771GM) operated by Southwest Helicopters, Inc. was involved in an aviation accident near Coolidge Dam, AZ. Investigators recorded the probable cause as: the pilot's selection of a cruise altitude insufficient to ensure adequate obstacle clearance and his inadequate visual lookout. A factor in the accident was the inconspicuousness of the power lines. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

A helicopter struck an unmarked power line while repositioning during a wildlife survey flight, resulting in a postimpact fire that destroyed the aircraft.

Accident Summary

During a wildlife population survey flight, a helicopter collided with an unmarked power line while cruising en route between 130 and 180 feet above ground level. The impact caused the helicopter to crash, and a postimpact fire ensued, completely destroying the aircraft.

Flight Details

The flight had been uneventful for approximately 1.5 hours before the pilot was directed to reposition the helicopter to another portion of the survey area. The mission, contracted by the State of Arizona Department of Fish and Game, required personnel transport over mountainous terrain and flight within 200 feet of ground level.

Obstructions

Prior to departure, the pilot had prepared regarding obstructions in the survey area. The accident power lines were depicted on the sectional chart, and several pilots reported that the lines were extremely difficult to observe. The helicopter was not equipped with a wire strike protection system.

Related events

Same aircraft family

All Bell 206 accidents →

Frequently asked questions

What happened in the 4 Jan 1994 Bell 206B accident near Coolidge Dam, AZ?

A helicopter struck an unmarked power line while repositioning during a wildlife survey flight, resulting in a postimpact fire that destroyed the aircraft.

What aircraft was involved and where did it happen?

The accident on 4 Jan 1994 involved a Bell 206B, registration N771GM, operated by Southwest Helicopters, Inc., at Coolidge Dam, AZ.

What was the probable cause of the accident?

the pilot's selection of a cruise altitude insufficient to ensure adequate obstacle clearance and his inadequate visual lookout. A factor in the accident was the inconspicuousness of the power lines.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001206X00636. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.