The Australian Transport Safety Bureau has warned helicopter operators to inspect their aircraft's drive shaft after a fatal crash in Launceston earlier this year.

The ATSB recommended operators of the UH-1H — sometimes known as the Huey — inspect the helicopter's drive shaft.

The advice comes from the ongoing investigation into a fatal accident involving a Huey near Launceston on February 14 this year.

A 41-year-old pilot was the only person on board when it crashed into a paddock while fighting a bushfire north of Lebrina.

The man died at the scene.

The ATSB noted: "Witnesses both on the ground, and within a nearby helicopter, observed the early release of the water load from the underslung bucket before the UH-1H commenced a left turn and descended toward nearby open terrain.

The ongoing examination of the wreckage determined that the helicopter's main drive shaft had failed, and there was evidence of severe frictional and wear damage to one portion of the shaft.

The investigation is continuing.