Buffalo, NY, USA
N105SJ
MBB BO-105C
The pilot departed with his crew for a medical pickup flight in a helicopter. Passing through about 200 to 300 feet, the pilot perceived a power loss. The paramedic seated in the left seat reported that he called the pilot's attention to the collective as the helicopter descended and the pilot grabbed the collective. The paramedic reported that the descent stopped abruptly, and then continued as the pilot lowered the collective. The pilot reported that although there were no indications of an engine problem and the needles were not split, he sensed that the engines were not responding to the movement of the collective, and he lowered the collective to set up for an autorotation. The helicopter struck the ground, and slid for a short distance. It then became airborne, as it passed through a gate in a fence, the tail rotor struck the right side of the fence and the tail rotor and tail boom separated from the helicopter. The helicopter continued in the air for about 200 feet, spinning as it traveled forward. Ground impact marks consistent with main rotor impact were found about 200 feet from where the tail rotor separated from the helicopter. The helicopter came to rest about 50 feet beyond the main rotor blade marks. Examination of the helicopter revealed damage consistent with the engines operating at impact. No evidence of any malfunctions were found with the engines or airframe. Fuel was found in both engines. In addition, the collective friction was loose, and the last pilot to fly the helicopter before the accident flight reported he left the collective friction loose. In a follow-up interview, the pilot reported he had not checked the collective friction prior to takeoff, but thought it was OK. He had no direct memory of taking his hand off the collective, but the paramedic reported that the position of the pilot's arm was consistent with his hand being off the collective. When questioned if he had misinterpreted a lowering collective for a power loss, the pilot replied, "I can't say I didn't, maybe I did."
On June 20, 2003, at 1546 eastern daylight time, a MBB BO-105C helicopter, N105SJ, operated by Mercy Flight Inc, was substantially damaged during a forced landing in Buffalo, New York, after departure from the Heussler Hamburg Heliport (O01), Buffalo, New York. The certificated commercial pilot received serious injuries, and the other two crewmembers received minor injuries. Visual meteorological conditions prevailed for the positioning flight, destined for Colden, New York, for a patient pickup. A company flight plan had been filed and activated for the flight that was conducted under 14 CFR Part 91. According to the pilot, the accident flight was the first flight after maintenance. The pilot reported further that the helicopter was topped off with fuel prior to the flight. He was seated in the right seat, and a paramedic occupied the left front seat, facing forward. A flight nurse was seated in the cabin, facing sideways. After engine start and warm-up, the pilot brought the helicopter to a hover. The engine instrumentation looked good, and he initiated a takeoff to the northeast. While climbing through an altitude of about 200 to 300 feet above ground level (agl), he sensed and heard what he perceived was a power loss. A check of the engine and rotor instrumentation did not reveal any problems, nor was there a split between the needles for the engines and the main rotor. He immediately lowered the collective and assessed the situation. He then momentarily raised the collective to see if there was an engine response, and did not feel one. He immediately lowered the collective again and initiated an autorotation. Touchdown occurred on a fenced parking lot. Initial touchdown was on the skids with some collective applied. The pilot pulled additional collective as he neared the fence, and the helicopter became airborne. As the helicopter passed over the fence, it initiated a nose right rotation about the vertical axis, then struck the ground hard. Both engines were running at flight idle after the helicopter came to rest. The pilot used the fuel shutoff valves to shut the engines down. The pilot was not certain on the amount of rotations to the right. The paramedic reported that he entered the global positioning navigation system (GPS) coordinates of their destination, while the pilot started and warmed up the engines. After takeoff, at an altitude of 200 to 300 feet agl, he noticed the collective was lowering, and he brought that to the pilot's attention. He could see that the pilot's arm was in the vicinity of the collective, but could not see if his hand was on it. While descending, he felt an abrupt arrest of descent when the pilot pulled up on the collective, then the helicopter nosed over and continued to descend. The helicopter struck the ground, bounced into the air, and rotated about 1 3/4 turns. During the rotation, the left side forward door separated from the helicopter. When the helicopter struck the ground a second time, the paramedic's seat collapsed down and to the left. The paramedic also reported that he did not see the pilot reaching for anything with his left hand prior to the descent or accident. He also did not observe the gauges. However, he did not observe any warning lights or hear any warning horns. When he exited the helicopter, the engines were running and sounded louder than at ground idle. They were, "really loud." The flight nurse reported that initially, the takeoff was uneventful. However, she felt the helicopter dip, and looked up front to see what was going on. It appeared to her that the pilot and paramedic were engaged in a discussion. She then heard the paramedic say, "this is going to hurt," followed by ground impact. After the helicopter stopped, she remembered the paramedic saying, "we have to get out." She said she was thrown about the cabin, and her flight helmet came off. She added that she had not used her shoulder harness during takeoff, and had previously loosened the chin strap on her helmet to talk to a patient during her last flight, and had not tightened it for takeoff. An inspector from the Federal Aviation Administration (FAA), reported that accident occurred in a vehicle parking lot that was divided by a chain link fence. Initial touchdown occurred west of the opening, with the helicopter headed west toward the opening in the fence. About 5 feet before the fence, the skid marks stopped. The tail rotor was found imbedded on the fence, on the right side of the opening. The tail boom was separated from the helicopter, and was beyond the fence. The helicopter came to rest beyond the fence with the skids spread. The fuel cell did not rupture, the hydraulic system was found in system # 1, and the cabin was wrinkled. The engines and transmission had shifted in the mounts and were separated. The last pilot to fly the helicopter prior to the accident flight reported that he had removed the friction prior to performing a hover to a dolly so the helicopter could be moved into the hanger for maintenance. The director of operations reported that when the helicopter was checked after the accident, the collective friction was found to be loose. On July 1, 2003, the helicopter was re-examined by representatives of the engine and airframe manufacturers under the supervision of an airworthiness inspector from the FAA. According to the representative from Rolls-Royce, reported that the fuel filter, and lines leading to the engine. No evidence of fuel contamination was found. A pneumatic system leak check confirmed continuity and the absence of air leaks. The drive shafts connecting both engines to the main transmission exhibited circumferential scarring. The failure mode on the shaft was consistent with a sudden stoppage of the main rotor system. In addition, the maintenance records for the engines were reviewed, including the recent maintenance where the fuel nozzles had been changed. No evidence of a power loss or any malfunction with the engine was found. According to a representative of American Eurocopter, flight control continuity was confirmed on the collective and cyclic. There were breaks in the flight control continuity for the tail rotor drive shaft and pitch control of the tail rotor. These breaks occurred in areas of separation of components on the tail boom. No breaks were found at rod-ends. Initial touchdown occurred about 40 feet before the fence, and about 200 feet past the fence, impact marks, consistent with main rotor blade impacts were found in the asphalt. The helicopter came to rest about 50 feet beyond the blade impact marks. The director of operations reported that if the collective friction was not properly set, and a pilot removed his hand from the collective, the collective would lower, and the helicopter would descend. The paramedic was re-interviewed. He reported that based upon viewing the arm of another pilot sitting in the cockpit and comparing that to where he observed the pilot's arm, the position of the pilot's arm was consistent with the hand not being on the collective. The pilot was re-interviewed. He was asked about his interpretation of the visual and aural cues that he observed, and questioned about the friction on the collective. The pilot reported that he thought the friction was set properly, but added that he had not checked it prior to takeoff. He said it felt OK at lift off. He had no direct memory of reaching for anything that would have required him to remove his hand from the collective. Further, when asked if he had perceived a descent from a loose collective that had lowered on its own, as a power loss, the pilot replied, "I can't say I didn't, maybe I did." According to the checklist used by Mercey Flight, a check of the friction on the collective is conducted prior to takeoff.
The pilot's improper interpretation of a descent as a power loss and subsequent decision to autorotate, which resulted in a hard landing. A factor in the accident was the collective friction.
Source: NTSB Aviation Accident Database
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