Aviation Accident Summaries

Aviation Accident Summary SEA96LA025

SCOTTS MILLS, OR, USA

Aircraft #1

N64DB

HUGHES 369D

Analysis

THE PILOT WAS RETURNING FOR A LOAD OF CHRISTMAS TREES. WHILE MANEUVERING THE HELICOPTER, THE EXTERNAL LOAD LINE AND HOOK CONTACTED THE GROUND. THE HOOK BOUNCED UP INTO THE MAIN ROTOR, STRUCK A BLADE AND RICHOCHETED INTO THE TAIL BOOM. THE TAIL BOOM SEPARATED, RESULTING IN A LOSS OF CONTROL.

Factual Information

On November 29, 1995 approximately 0930 Pacific standard time, a Hughes 369D helicopter, N64DB, sustained substantial damage when it collided with the ground after the loss of the tail boom. The commercial pilot sustained minor injuries. No flight plan was filed for the flight, which was conducted in visual meteorological conditions. The aircraft was conducting external load operations lifting christmas trees. FAA inspectors noted that the external load hook, which weighed about ten pounds, had snagged to an object on the surface after the pilot had dropped a load and was climbing upslope to pick up another load. The hook flew up into the main rotor disk, striking one main rotor blade, causing a large dent or gouge and loss of a piece of the trailing edge. The hook then ricocheted into the tail boom, knocking off the aft portion of the tail boom and the tail rotor assembly, which fell to the ground. According to witnesses, the helicopter turned about two 360 degree turns before colliding with the ground, where it impacted on its right side. The hook was found about 300 feet from the aircraft. The pilot stated that he had dropped a load of trees and was flying approximately 30 knots indicated airspeed, 70 feet above the ground and had travelled about 75-100 yards away from the pile of trees, when the helicopter yawed about 90 degrees to the right in a strong gust of wind. Before he could correct for the yaw, the hook, on a 25 foot line, flew up and came in contact with the main rotor, causing the helicopter to come down and hit the ground, then roll on its side.

Probable Cause and Findings

THE PILOT'S FAILURE TO MAINTAIN ADEQUATE CLEARANCE FROM THE GROUND.

 

Source: NTSB Aviation Accident Database

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