Casualties unknown

1989-08-14: Bell 47G-2A-1 (N49HB) — Wisconsin Dells, WI

Wisconsin Dells, WI, US

On August 14, 1989, a Bell 47G-2A-1 (registration N49HB) was involved in an aviation accident near Wisconsin Dells, WI. Investigators recorded the probable cause as: ATTEMPT BY THE PILOT TO EXCEED THE HOVER PERFORMANCE CAPABILITIES OF THE HELICOPTER, AND OPERATING OUTSIDE THE WEIGHT AND BALANCE LIMITATIONS. 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 sightseeing helicopter failed to sustain flight and landed hard after a downwind takeoff from a raised helipad. Investigation revealed excessive weight and center of gravity beyond limits.

Summary

A helicopter operating as an aerial sightseeing concession experienced a hard landing after attempting a downwind takeoff from a raised helipad, referred to as a pinnacle. The aircraft failed to sustain flight and impacted the ground with significant force.

Details of the Event

According to witnesses at the scene, the helicopter departed from the pinnacle in a generally easterly direction. When questioned about the wind conditions at the time of takeoff, the pilot reported westerly winds of approximately 6 to 8 knots. The takeoff direction was therefore downwind relative to the reported wind.

Pilot Statement

During an interview, the pilot stated that after clearing the pinnacle, he perceived a loss of power. He reported being unable to maintain rotor RPM even with the throttle fully open. The helicopter subsequently descended and landed hard.

Investigation Findings

Post-accident inspection of the helicopter revealed no defects in either the airframe or the powerplant. The investigation determined that the aircraft was too heavily loaded to hover out of ground effect at the density altitude of the accident site, which was 2500 feet. Additionally, the center of gravity was found to be outside the allowable range. These conditions likely affected the helicopter's performance and controllability during the downwind takeoff.

Conclusion

The accident involved a sightseeing helicopter that, after a downwind departure from a pinnacle, was unable to maintain flight and landed hard. The investigation identified the aircraft's weight and center of gravity as contributing factors, though no mechanical defects were discovered.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X29066. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.