Aviation Accident Summaries

Aviation Accident Summary SEA97TA023

FILLMORE, UT, USA

Aircraft #1

N3098G

Bell 47G-3B-1

Analysis

The helicopter pilot had completed about 20 seeding runs, and had landed at the same landing zone. The landing was describe as the same as the previous landings, in that the bucket touched down on the ground, then the pilot maneuvered the helicopter backwards and touched down with the bucket in front of his position. Witnesses reported that after the 2 ground crew members filled the seed bucket, both moved away to avoid the rotor wash; one went behind a rock, while the other moved near the seed bags and turned his back toward the helicopter. As the helicopter lifted off from the landing zone, one of three 40-foot long lines (attached to the seed bucket) looped over the right skid. The helicopter continued to gain altitude as the seed bucket began to tip and drop seed. Witnesses (about 50 yards downhill from the landing zone) reported that the pilot appeared to be having trouble controlling the helicopter as it gained altitude and moved forward. The helicopter continued into rising terrain and collided with a 45 degree slope in a nose down attitude and slightly to the right side. Inspection of the helicopter after the accident revealed that the pilot had jettisoned the load and the hook had released at the belly of the helicopter before collision with the terrain; however, the line remained entangled around the right skid.

Factual Information

On October 29, 1996, at 1547 mountain standard time, a Bell 47G-3B-1, N3098G, registered to Versatile Helicopter, operated by the United States Forest Service as a public use flight, collided with mountainous terrain located 12 miles south of Fillmore, Utah. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The helicopter was substantially damaged and the commercial pilot, the sole occupant, was fatally injured. The helicopter had been seeding a previously burned area since early morning and had been taking off and landing at a landing zone near the accident site. United States Forest Service personnel reported that on the day of the accident, seeding operations began at 0820. The seed bucket had three 40-foot long cables attached to it that came together at a sway bar. The sway bar then connected to a hook under the belly of the helicopter. The helicopter had successfully completed 20 seeding runs and had landed at the same landing zone for the next load of seed. The landing was described as the same as the previous, in that the bucket would touch down on the ground and then the pilot would maneuver the helicopter backwards and touch down with the bucket in front of him. The two ground crew then loaded the seed in the bucket without doing anything to the three lines that were attached to the bucket. After the loading was complete, one of the ground crew members moved to the front of the helicopter and behind a large rock, while the other ground crew member moved to the right of the helicopter, near the stack of seed bags, and turned his back to the helicopter and put his head down to avoid the helicopter's rotor wash as it lifted off. Three forest service personnel, who were located approximately 50 yards downhill from the landing zone, reported that as the helicopter lifted off, they observed that one of the 40-foot lines attached to the seed bucket was looped over the right skid. The witnesses also observed that the seed bucket was tilting to the left and seed was dropping from the bucket. The witnesses stated that it appeared that the pilot was having problems controlling the helicopter as it continued to gain altitude and forward movement. The helicopter continued into the nearby rising terrain and collided with a 45 degree sloping mountain in a nose down attitude and slightly to the right side. The helicopter then rolled and slid down the mountain, coming to rest right-side up. Documentation of the accident site, provided by Forest Service personnel, indicated evidence that the cable was positioned over the forward section of the right side skid. It appeared that the pilot had jettisoned the load and the hook had released at the belly of the helicopter prior to the collision, however, the cable remained entangled on the right side skid to the point of impact. The pilot survived the accident and later passed away in the hospital. Dr. Todd C. Grey of the Office of the Medical Examiner, Salt Lake City, Utah, reported that the pilot's cause of death was due to craniocerebral injuries. Toxicological samples were taken and sent to the Federal Aviation Administration Civil Aeromedical Institute, Oklahoma City, Oklahoma, for analysis. The analysis reported that Lidocaine was detected in the pilot's blood and urine.

Probable Cause and Findings

inadequate procedure and inadequate monitoring by the pilot, the operator, and/or other personnel, which allowed one of three external cables to the seed bucket to become entangled with the right skid of the helicopter, resulting in an imbalance and loss of aircraft control as weight on the cable became effective. Lack of air/ground communication between the pilot and ground crew personnel was a related factor.

 

Source: NTSB Aviation Accident Database

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