Casualties unknown

1994-08-26: Bell 47 MARK-6 (N19JM) — Northland Helicopter Inc — Lake City, MN

Lake City, MN, US

On August 26, 1994, a Bell 47 MARK-6 (registration N19JM) operated by Northland Helicopter Inc was involved in an aviation accident near Lake City, MN. Investigators recorded the probable cause as: THE LOSS OF LIFT RESULTING FROM THE PILOT'S FAILURE TO MAINTAIN ROTOR RPM DURING AN AERIAL APPLICATION TURN. THE POWER AVAILABLE FROM THE ENGINE WAS LESS THAN THAT REQUIRED TO REGAIN THE LOST ROTOR RPM. 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

During a low-level agricultural turn, a helicopter experienced lower than normal rotor RPM. Attempts to regain RPM and level off failed, leading to spray boom contact with a corn crop and the helicopter overturning.

Accident Overview

A helicopter conducting an agricultural application flight experienced a loss of rotor RPM during a low-level turn. The pilot reported that after completing the turn, the rotor RPM was lower than normal. Environmental conditions included a temperature of approximately 74 degrees Fahrenheit and high humidity, with a density altitude of about 2,000 feet.

Sequence of Events

The pilot attempted to regain rotor RPM and level the helicopter, but these efforts were unsuccessful. Subsequently, the helicopter's spray booms contacted the corn crop below. The helicopter then came to a stop and overturned.

Conditions

The ambient temperature was reported as 74°F, and the pilot noted high humidity. The density altitude was calculated to be approximately 2,000 feet.

Outcome

The helicopter sustained damage from the impact with the crop and the overturn. No further details were provided regarding injuries or the extent of damage.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001206X02021. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.