20030522010859A

(-23) The aircraft was destroyed following an in-flight breakup after a 41' external load cable became entangled with the tail rotor over the island of Kahoolawe, Hawaii. The helicopter was registered to pacific helicopter services LLC, of kahului, Hawaii, and operated by pacific helicopters, inc. the commercial helicopter pilot, who was the sole occupant, was fatally injured. The flight was operated as public use under the provisions of 14 CFR part 133 under a contract with the U.S. Navy for ordinance cleanup on Kahoolawe. The flight departed a landing zone (lz) on Kahoolawe approximately 5 minutes prior to the accident, and was destined for puunene, maui, Hawaii. According to the operator, the pilot had conducted three external load transports earlier that day between nuunene and Kahoolawe, with the last one being a 3,000-pound fuel pod via its 41' external load cable. The pilot dropped off the fuel pod at lz squid and departed with the 41' cable still attached. The 41' cable was made of steel and had a hook positioned at the load end. The cable was not weighted for the return flight to puunene. One witness, located on the island of Kahoolawe, indicated he heard the helicopter fly overhead and looked up. He observed the helicopter with an "un-weighted cable swinging free under the aircraft." The witness saw the cable "slap the undercarriage one time before the cable impacted the tail rotor." He then observed the tail rotor coming apart. The witness looked away from the helicopter shortly (due to unstable footing) and when he looked back, the helicopter had "rotated and spun nearly upside down," and he watched it descend until impact. He added he could tell the cable was un-weighted "due to the way it moved freely under the aircraft...because of the aircraft speed and the cable being un-weighted, it (the cable) was able to slap the underside of the aircraft." Additional witnesses heard three loud bangs or pops described as a gunshot, explosion, or metal hitting metal. As they looked up to see the helicopter they noticed the tail rotor coming apart. One witness heard another pop and then noticed the main rotor separate from the helicopter. Another witness indicated she observed the main rotor blade rotation slow after the tail rotor debris fell from the helicopter, then the main rotor system separated. A few witnesses observed the helicopter rolling to the right. The helicopter impacted the ground inverted, and by the time the witnesses reached the accident site, the helicopter's cockpit, cabin section was engulfed in flames. The witnesses who first responded to the accident site indicated the helicopter was severely damaged and they did not receive any response to their calls. The tail rotor hub separated from the helicopter and came to rest 20 degrees 34 minutes north latitude and 156 degrees 38 minutes west longitude. The tail rotor blades remained attached to the hub; however, the outboard section of one of the blades had separted. At the blade separation area, cable witness marks were noted. The main rotor blades sustained some minor damage and were still attached to the hub. The main rotor blades were located 20 degrees 32 minutes latitude and 156 degrees 38 minutes west longitude. The main wreckage, which included everything except the main rotor blades, the tail rotor blades, a door, and a section of separated sheet metal, came to rest at 20 degrees 34 minutes north latitude and 156 degrees 38 minutes west longitude. The cable came to rest in and adjacent to the main wreckage. The main rotor mast separated at the blade flapping stops, and displayed indentations consistent with the flapping stop locations. The mast fracture surfaces displayed 45-degree sheer lips. The engine turbine case displayed punctures from the inside out, and the turbine blades were fractured and displayed heat damage. The engine's compressor section was completely destroyed with its entire rotor and stator blades found separated and/or burned.