Aviation Accident Summaries

Aviation Accident Summary DEN02LA013

Bryce, UT, USA

Aircraft #1

N911KH

Bell 206B

Analysis

The helicopter was fueled to capacity the evening before, and the engine compartment was preheated before departure. Preflight inspection revealed no frost on the airframe or rotor blades. The particle separator was clean and dry. Engine start and takeoff were normal. After crossing a highway 1/2 mile south from the heliport, at an airspeed "in excess of 50 mph [and] at an altitude of approximately 50-70 feet," the engine "flamed out." There was a noticeable yaw and the pilot heard "the sound of the engine shutting off." He autorotated towards a highway right-of-way. The helicopter struck the ground hard and slid 20 to 30 feet. "Mast bumping" broke the rotor head off. It struck the rear of the helicopter, severing the tail section. The helicopter spun around and rolled over on its right side. Postaccident examination disclosed no fuel remaining because the rear skid leg had punctured the fuel tank. The pilot and his two passengers had been drenched with fuel when they evacuated the helicopter. All fuel lines and fuel filter were intact, free of debris, and contained fuel. The turbine and compressor turned freely by hand. The pilot said he noted dirt on the inside of the cap "consistent with the dirt at the crash site." Later, he wrote that "the dirt on the inside of the fuel cap was orange, the same color as at the heliport. The dirt at the crash site is more brown native soil." He noted vehicle tracks in the snow behind the helipad. Footprints led from the tire tracks to a small dirt pile and back to the helipad. Suspecting the helicopter may have been sabotaged, the pilot contacted the Federal Bureau of Investigation (FBI) field office in St. George, Utah. He said that in the 6 years the company has been doing business in the Bryce Canyon area, he had been slandered, vandalized, and threatened with death. According to the FBI special agent, his agency would not become involved unless there was "conclusive evidence" that a crime had been committed.

Factual Information

On December 1, 2001, approximately 1215 mountain standard time, a Bell 206B, N911KH, operated by Alladin Air Service as a nonscheduled domestic passenger sightseeing flight, was substantially damaged when it collided with terrain during a forced landing near Bryce, UT. The pilot and two passengers sustained serious injuries. Day visual meteorological conditions prevailed, and a company VFR flight plan had been filed for the local flight being conducted under Title 14 CFR Part 135. The flight originated at Bryce approximately 1215. According to the pilot's accident report, the helicopter was fueled to capacity the evening before, and the engine compartment was preheated before departure. His preflight inspection revealed no frost on the airframe and rotor blades. The particle separator was clean and dry. Engine start and takeoff were normal. After crossing a highway 1/2 mile south from the heliport, at an airspeed "in excess of 50 mph [and] at an altitude of approximately 50-70 feet," the engine "flamed out." There was a noticeable yaw and the pilot heard "the sound of the engine shutting off." He autorotated towards a highway right-of-way. The helicopter struck the ground hard and slid 20 to 30 feet. "Mast bumping" broke the rotor head off. It struck the rear of the helicopter, severing the tail section. The helicopter spun around and rolled over on its right side The passenger in the rear seat videotaped the flight, including the accident sequence, and a copy was made available for examination. As the helicopter sat on the helipad with its rotor blades turning, a male could be seen walking around the front of the helicopter and getting into the right seat. Engine sounds were normal during takeoff and climb-out. Shortly thereafter, a warning horn was clearly audible. In initial telephone conversations with the pilot, he said he suspected a faulty fuel control unit (FCU) was to blame for the power loss. This was the second "loaner" FCU a Dallas overhaul facility had sent him to use while his FCU was overhauled. He submitted three FAA Form 8130-3s (Airworthiness Approval Tags) for documentation. The helicopter was transported to the company's hangar at Panguitch Airport where, on December 4 and 5, it was examined by an FAA aviation safety inspector and a Rolls-Royce investigator. Although the pilot said the helicopter had been fueled to capacity, no fuel remained because the rear skid leg had punctured the tank. The pilot and his two passengers had been drenched with fuel when they evacuated the helicopter. All fuel lines and fuel filter were intact, free of debris, and contained fuel. The turbine and compressor turned freely by hand. The pilot wrote, "I also noted the fuel cap, when removed and examined, had dirt on the inside of the cap consistent with the dirt at the crash site." In an undated letter submitted shortly after the accident, the pilot said he became suspicious about the dirt on the inside of the fuel cap, so he took soil samples from the accident site and from the helipad. "The dirt on the inside of the fuel cap was orange, the same color as at the heliport. The dirt at the crash site is more brown native soil," he wrote. He noted vehicle tracks in the snow behind the helipad. Footprints led from the tire tracks to a small pile of orange-colored dirt and back to the helipad. Suspecting the helicopter may have been sabotaged, the pilot contacted the Federal Bureau of Investigation (FBI) field office in St. George, Utah. He said that in the 6 years the company has been doing business in the Bryce Canyon area, he had been slandered, vandalized, and threatened with death. According to the FBI special agent, his agency would not become involved unless there was "conclusive evidence" that a crime had been committed.

Probable Cause and Findings

loss of engine power for reasons undetermined. Contributing factors were the low airspeed and altitude at which to perform an autorotation.

 

Source: NTSB Aviation Accident Database

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