Aviation Accident Summaries

Aviation Accident Summary LAX98TA278

PORTERVILLE, CA, USA

Aircraft #1

N605RA

Aerospatiale SA316B

Analysis

The helicopter had a bambi bucket on a 100-foot-long line. The bucket became entangled in some trees and the line snapped and wrapped itself around the tail rotor. The tail rotor blades and gearbox separated from the aircraft and the helicopter spun to the ground and rolled down a steep slope. The pilot did not report any mechanical malfunction with the aircraft prior to the accident. Wire marks were found on the tail rotor blades and around the output shaft.

Factual Information

On August 27, 1998, at 1545 hours Pacific daylight time, an Aerospatiale SA316B, N605RA, operated by the U.S. Department of the Interior, sustained substantial damage after entangling a bambi bucket in a tree near Porterville, California. The airline transport pilot, the sole occupant, was not injured. The public-use aircraft operating under 14 CFR Part 91 was performing a fire mission at the time of the accident. No flight plan was filed and visual meteorological conditions prevailed. Witnesses saw the helicopter fly down the side of a ridge with the bambi bucket on a 100-foot-long line. The bucket became entangled in some trees and the line snapped and wrapped itself around the tail rotor. The tail rotor blades and gearbox separated from the aircraft and the helicopter spun to the ground and rolled down a steep slope. Witnesses reported that the terrain was mountainous, with 40 to 50 degree slopes. The pilot did not report any mechanical malfunction with the aircraft prior to the accident. A Federal Aviation Administration inspector from the Fresno, California, Flight Standards District Office traveled to the site and reported that there were wire marks on the tail rotor blades and around the output shaft of the gearbox.

Probable Cause and Findings

The pilot's failure to maintain adequate in-flight clearance between the bucket and trees resulting in the entanglement/separation of the long line and subsequent impact with and separation of the tail rotor assembly. A factor was the trees.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports