Casualties unknown

Helicopter Lands Upside Down in Lake After Impacting Levee (N73241)

Houma, LA, US

On June 5, 1990, a Bell 47G3-B (registration N73241) was involved in an aviation accident near Houma, LA. Investigators recorded the probable cause as: THE PILOT'S FAILURE TO MAINTAIN ROTOR RPM AND AN EXCESSIVE SINK RATE. 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 2026-07-04Data APIEditorial standards

A helicopter rolled over and settled upside down in a lake after the pilot attempted a slide-on-landing when collective pitch controls failed to respond during a landing near an alligator's nest.

Incident Overview

A helicopter came to rest upside down in a lake after the pilot experienced a loss of response from the collective pitch controls while attempting to land near an alligator's nest. The pilot reported that during the landing approach, the helicopter did not respond to collective pitch inputs. In response, he attempted to perform a slide-on-landing onto the water surface. However, the rear portion of the fixed flotation gear struck a levee, causing the helicopter to pitch forward and roll over before settling inverted in the lake.

Post-Event Examination

An examination of the helicopter's flight controls following the accident revealed no pre-impact anomalies or malfunctions. The control systems were found to be functional and intact, indicating that the failure to respond to collective pitch inputs may have been related to other factors not identified during the inspection.

Operational Context

The landing was being conducted near a lake in close proximity to an alligator's nest. The pilot's decision to attempt a water landing was prompted by the unresponsive collective pitch controls. The impact with the levee occurred as the helicopter touched down on the water, leading to the subsequent rollover.

Condition of the Helicopter

The helicopter came to rest inverted in the lake. The extent of damage resulting from the impact and rollover was not specified. No information was provided regarding the occupants or any injuries sustained.

Frequently asked questions

What happened in the 5 Jun 1990 Bell 47G3-B accident near Houma, LA?

A helicopter rolled over and settled upside down in a lake after the pilot attempted a slide-on-landing when collective pitch controls failed to respond during a landing near an alligator's nest.

What aircraft was involved and where did it happen?

The accident on 5 Jun 1990 involved a Bell 47G3-B, registration N73241, at Houma, LA.

What was the probable cause of the accident?

THE PILOT'S FAILURE TO MAINTAIN ROTOR RPM AND AN EXCESSIVE SINK RATE.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23414. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.