RAEFORD, NC, USA
N111FX
PILATUS PC-6/B1-H2
THE PILOT WAS PERFORMING THE INITIAL TAKEOFF, WHEN HE OBSERVED A LOSS OF POWER, ASSOCIATED WITH A TORQUE INDICATION OF ZERO. HE FORCE LANDED THE AIRCRAFT IN A WOODED AREA WHEN HE COULD NOT MAKE AN OPEN FIELD. A POST ACCIDENT INSPECTION OF THE ENGINE REVEALED THAT THE FUEL CONTROL UNIT ARM WAS LOOSE, AND THE LOCK WIRE WAS NOT IN PLACE. THE ARM WAS POSITIONED SO THAT A MAXIMUM POWER DEMAND FROM THE THROTTLE WOULD CORRESPOND TO AN IDLE POWER DEMAND AT THE FUEL CONTROL. THE ENGINE UNDERWENT A 100 HOUR INSPECTION, BY COMPANY MAINTENANCE PERSONNEL, 8 DAYS PRIOR TO THE ACCIDENT. THE INSPECTION CHECKLIST CALLED FOR EXAMINING THE FUEL CONTROL LINKAGE FOR SECURITY.
On July 9, 1994, at 1015 eastern daylight time, a Pilatus PC-6/B1-H2, N111FX, was destroyed following a collision with terrain during a forced landing attempt near Raeford, North Carolina. The commercial pilot and his pilot-rated passenger received minor injuries. The aircraft was being operated under the provisions of 14 CFR Part 91 by Freefall Express, Incorporated of Deland, Florida. Visual meteorological conditions existed at the time, and no flight plan had been filed for the local, personal flight. The pilot reported the following: He departed the Raeford Airport with the intention of staying in the local traffic pattern. The takeoff from runway 22 was normal (propeller 100 percent, torque 35 pounds, with six turns of flaps). After liftoff, he retarded the propeller to 90 percent, and the torque to 30 pounds. He raised the flaps, and initiated a left turn, while remaining in a climb. He then observed that the climb rate was slow, and initiated another left turn. The torque then went to zero. The aircraft began to lose altitude, and he referred to the emergency checklist. He set up for a forced landing, while continuing his attempts to regain torque. Unable to make it to an open field, the aircraft was landed in a wooded area. A fire began in the engine area, and the pilots exited the aircraft through the co- pilot's windshield. A cursory inspection of the engine was performed at the Raeford Airport. The inspection revealed that the fuel control arm extension was loose, and the lock wire was not present. The engine was then shipped to the Pratt and Whitney manufacturing facilities in Longueuil, Quebec, Canada, for a detailed examination. The examination revealed that the fuel control arm extension lock wire was not in place, and the extension could be loosened by hand. The fuel control unit arm was positioned approximately 60 degrees in advance of the normal relationship with the fuel control unit spindle, such that with the input lever positioned to command maximum power, the fuel control unit spindle position corresponded to the idle power position. The lock wire fastening holes of both the fuel control unit arm and the extension appeared uniformly fire and soot discolored, with no marks suggestive of the presence of lock wire prior to the fire and soot discoloration. The fuel control unit arm adjusting spacer serrations and the mating serrations of the fuel control unit arm and spindle displayed uniform sooting and fire discoloration. The compressor centrifugal impeller and shroud, the compressor turbine and interstage baffle, and the power turbine and power turbine guide vanes displayed light circumferential rubs. The engine manufacturer's representative reported that these rubs were consistent with axial contact under impact loads and external engine case distortion. He also reported that these rotational signatures were characteristic of an engine developing idle range power at impact. The last inspection of the aircraft occurred on July 1, 1994 (an annual inspection). The inspection included the engine, and a 100 hour checklist was completed by the operator. Under the "Fuel System" section of the checklist was the following entry, initialed by the operator's mechanic: "(4) Fuel control for security and leakage. Check linkage and sense-lines."
THE IMPROPER INSPECTION OF THE AIRCRAFT BY COMPANY MAINTENANCE PERSONNEL, WHICH RESULTED IN AN UNSAFETIED AND DISCONNECTED FUEL CONTROL ARM.
Source: NTSB Aviation Accident Database
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