HELPER, UT, USA
N50330
Hawkins & Powers UH-1B
As the helicopter approached logging personnel with a 150 foot long line, the pilot heard a 'Shhhh' sound and was advised smoke was coming from the engine. He turned and proceeded down the mountain. The engine then 'quit.' The helicopter collided with heavily wooded steep terrain. The number 1 and 2 bearings were submitted for metallurgical examination. The metallurgical report stated that 'the most likely cause of [the] engine malfunction was degradation of the Position #1 bearing due to insufficient lubrication.' All other damage appeared to be 'secondary.' The accessory carrier assembly was oil flow tested and found to be 'acceptable,' albeit 'near the lower end of requirements.' Debris in the bearing oil strainer was believed to be 'coked oil and epoxy hardener, both unusual for this area of the engine.'
On April 1, 2000, approximately 1430 mountain standard time, a Bell UH-1B, N50330, registered to and operated by Precision Air, LLC, of Provo, Utah, was destroyed when it collided with terrain while maneuvering 15 miles northwest of Price, Utah. The airline transport certificated pilot sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan had been filed. The helicopter was being operated under Title 14 CFR Part 133. The flight originated at a nearby staging area at an undetermined time. According to the pilot's accident report, he was logging with a 150 foot long line. As he approached ground personnel, he heard a "Shhhh" sound and was advised there was smoke coming from the engine. Seeing smoke on the left side of the helicopter, he turned and proceeded down the mountain. The engine then "quit." The terrain was wooded and steep, and he attempted to fly towards a clearing. He "pulled pitch" to clear trees. The rotor blades struck the trees and the helicopter fell into a snow bank. The wreckage was moved to a sawmill in Price, Utah, where, on April 19, the Lycoming T53-L-13 turboshaft engine was given a preliminary examination by FAA inspectors and representatives from Honeywell. A more detailed examination followed at Precision Air's hangar in Provo, Utah. The number 1 and 2 bearings and the number 1 sealing nut were submitted to Honeywell's metallurgical laboratory in Phoenix, Arizona, for examination. According to its report, "the most likely cause of [the] engine malfunction was degradation of the Position #1 bearing due to insufficient lubrication." All other damage appeared to be "secondary." The accessory carrier assembly was oil flow tested and found to be "acceptable," albeit "near the lower end of requirements." Debris in the bearing oil strainer was believed to be "coked oil and epoxy hardener, both unusual for this area of the engine." In a telephone interview, the pilot stated he had previously experienced a number 1 bearing failure in another, but similar, helicopter. The operator was asked to submit the engine maintenance records but has gone out of business, and all attempts to contact him have been to no avail.
Total failure of the number 1 bearing due to lack of lubrication, the oil flow being restricted by a foreign object (epoxy hardener). Factors were trees and the unavailability of suitable terrain for a forced landing.
Source: NTSB Aviation Accident Database
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