CHI08FA141

The pilot's failure to maintain tail rotor obstacle clearance from a tower during takeoff.

The air ambulance helicopter was departing from a hospital heliport that was located on the 11th story of the hospital during an FAA Part 135 check. Before takeoff, the pilots discussed the construction cranes that were operating on the north side of the hospital and their effect on the approach and departure routes to the pad. The pilot reported that he lifted the helicopter straight up into a vertical takeoff. The torque was about 94 percent and "everything was nominal." The helicopter was about 40 feet in the air when the pilot heard a "pop" and the helicopter started to yaw to the right and vibrate. He attempted to land back on the helicopter pad by using the cyclic and lowering the collective, but the main rotor blades impacted the 32-foot high brick structure located east of the helicopter pad. The helicopter fell straight down impacting the hospital roof. Witnesses observed the helicopter lift off the helipad and then fly backwards until the tail rotor hit a tower on top of the roof. A hospital security video camera showed the helicopter fly backwards as it lifted off the helicopter pad. It showed that the tail rotor appeared to strike an object on one of the towers, and the tail rotor immediately shattered and the helicopter went into a right yaw. A camera that was mounted on one of the towers exhibited impact marks and carbon fibers were found lodged in a crevice of the camera body. Based on the analysis of the accident site, the helicopter traveled about 61 feet straight-line distance rearwards at an angle of about 41-51 degrees relative to the hospital pad. The time from takeoff to impact with the camera was about 11.37 seconds. The inspection of the helicopter revealed no preexisting anomalies that would preclude normal operation.

HISTORY OF FLIGHT On May 29, about 1101 eastern daylight time, a Sikorsky S-76A helicopter, N176SH, operated by Aero Med Spectrum Health, was destroyed by post impact fire after the tail rotor struck a tower while departing from the heliport (MI97) on top of the Spectrum Health Hospital, Grand Rapids, Michigan. The airline transport (ATP) certificated pilot and the ATP certificated Federal Aviation Administration (FAA) inspector received serious injuries. The 14 Code of Federal Regulations Part 91 flight departed the Gerald R. Ford International Airport (GRR), Grand Rapids, Michigan, at 1041. Visual meteorological conditions prevailed at the time of the accident and a company flight plan was filed. The pilot reported the flight was a FAA Part 135 check, which included an annual Sikorsky proficiency check and a 6-month helicopter instrument proficiency check. The flight departed GRR and flew the FAA-approved Global Positioning System (GPS) "point in space" approach to the termination point just south of the hospital. The flight then proceeded visually to the Spectrum Health Helipad and landed on the north spot. When the helicopter landed, the nose was pointed about 340 degrees. Before takeoff, the pilots discussed the construction cranes that were operating on the north side of the hospital and their effect on the approach and departure routes to the pad. The pilot reported that he lifted the helicopter straight up during the takeoff. The torque was about 94 percent and "everything was nominal." The helicopter was about 40 feet in the air when the pilot heard a "pop", and the helicopter started to yaw to the right and vibrate. The pilot reported that he instinctively added left pedal to counteract the right yaw, and it seemed that he had some tail rotor authority. Then the rate of the right yaw increased rapidly. He attempted to land back on the helicopter pad by using the cyclic and lowering the collective, but the main rotor blades impacted the 32-foot high brick structure located east of the helicopter pad. The helicopter fell straight down impacting the hospital roof. The FAA inspector, who was sitting in the left seat, reported that the helicopter lifted up normally in a vertical takeoff to about 40 - 50 feet. He stated that the helicopter went straight up. He reported that he was observing the construction cranes and looking out and down during the takeoff. About 40 feet, he heard a "pop" and saw the pilot moving the cyclic. The helicopter started turning right and descending, and then the main rotor blades hit the building. The helicopter went straight down and impacted hard onto the roof. He exited the helicopter by screwing the copilot's pedals all the way aft and "shimmying" out the copilot's chin bubble on his back. He helped the pilot get out of the helicopter through the chin bubble, and they got behind a heating duct on the roof until the fire fighters arrived. A fire had started during the initial impact, and soon after the pilots exited the helicopter, it was consumed by fire. A hospital nurse reported that she heard the helicopter and went to the window to watch it takeoff. She saw the helicopter as it lifted off the pad and as it flew backwards toward the brick hospital structure and the radio towers on top of the structure. She saw the helicopter's tail rotor hit a tower. A witness observed the accident from a 7th floor window across the street from the helicopter pad. He reported that the helicopter's tail rotor clipped the radio tower about mid-span and the tail rotor immediately disintegrated. A hospital security video camera, which was located near the top of the brick structure and overlooked the helicopter landing pads, recorded a portion of the accident flight. It showed the helicopter as it came in for landing from the south and landed on about a 340-degree heading on the north landing spot. The helicopter stayed on the deck for about 3 minutes before it departed. The video showed the helicopter as it lifted off the north landing spot and as it flew backwards toward the brick structure while the nose of the helicopter remained pointing to the northwest. It showed the helicopter as it went out of view of the video recorder as it continued to climb. Since it was a sunny day, the shadow of the helicopter and the towers on top of the brick structure were visible on the helicopter pad below. The shadow of the helicopter's tail rotor appeared to strike an object on one of the towers. The tail rotor immediately shattered and the helicopter went into a right yaw. The helicopter came back into the view of the video recorder as the main rotor blades impacted the brick structure. The video recording stopped and did not record the helicopter hitting the hospital roof. A camera that was mounted on one of the towers was removed for inspection. The camera body and its support frame exhibited impact marks. Carbon fibers were found lodged in a crevice of the camera body. The support structure that supported the camera exhibited impact marks. PERSONNEL INFORMATION The pilot was a 61-year-old airline transport pilot with single-engine and multi-engine airplane land and helicopter ratings. He held instrument ratings in airplanes and helicopters. He held a second-class medical certificate issued on March 18, 2008. He had about 7,260 total flight hours, which included about 6,760 hours flown in helicopters. He flew about 25.8 hours in the make and model in the last 90 days. His most recent training was at Flight Safety International on May 4, 2008. His most recent Part 135 airman competency/proficiency check was successfully accomplished on November 1, 2007. The FAA inspector was a 57-year-old airline transport pilot with single-engine and multi-engine airplane land and helicopter ratings. He held instrument ratings in airplanes and helicopters. He held a second-class medical certificate issued on January 24, 2008. He had about 7,000 total flight hours, which included about 1,200 hours in helicopters. His annual helicopter check, required for participants in the FAA's flight program, was successfully accomplished on July 7, 2007. AIRCRAFT INFORMATION The helicopter was a Sikorsky S-76A, serial number 760260, manufactured in 1984. Two Allison 650 shaft horsepower 250-C30S engines powered the helicopter. The helicopter was purchased by Aero Med and configured for emergency medical services (EMS) in 1997. The cockpit was equipped with dual electronic flight information systems (EFIS) and dual digital automatic flight control system (DDAFCS) instruments. It was equipped with instrument flight rules (IFR) capable instrumentation and was certified for IFR flight. The cabin was fitted with a custom EMS interior with two aft facing and two forward facing seats, with a center-mounted stretcher. Aero Med maintained the aircraft in accordance with an FAA approved aircraft inspection program (AAIP). The computer based program tracked all flight and maintenance actions, and was backed up by corresponding paper logs. An FAA inspection of the maintenance records indicated that the logbooks were current and in order, and that the helicopter was in an airworthy condition for the flight. According to the aircraft flight logbook, the helicopter had logged 5,195.4 hours and 19,153 cycles of total time prior to the accident flight. The operator reported the mission takeoff fuel load was 1,200 pounds. The gross weight and center of gravity (CG) at takeoff were reported to be 9,762 pounds at 200.3 inches, which were within the CG limits. METEOROLOGICAL INFORMATION At 1053, the surface weather observation at GRR, located about 8 nautical miles south of the accident site, was: Winds calm, visibility 10 miles, ceiling broken at 22,000 feet, temperature 18 degrees Celsius (C), dew point -7 degrees C, altimeter 30.25 inches of Mercury. HELI