CHI05FA274

The helicopter was being operated for hire providing rides during a festival when it struck a power line over a lake. Visual meteorological conditions prevailed at the time of the accident. A witness stated that he heard the helicopter for approximately one minute and during that time he heard a pitch change, heard the revolutions per minute increase, and then heard the crash. The power line was at a height approximately equal to the height of the trees surrounding the lake. According to the operator, no safety briefings were given to ride passengers and the helicopter was not shut down when passengers were loaded and unloaded. A previous ride passenger stated that when he arrived on the morning of the accident, there was no safe area delineated around the helicopter and no safety briefing given. This witness stated that the engine was running when the pilot got out of the helicopter in order to secure the passenger's seatbelts. There had been a written complaint regarding the operator when a witness saw the helicopter being operated in a "manner contrary to all safety guidelines outlined in the manufacturer's Safety Course and Special Federal Aviation Regulation 73.1." The owner of the company stated that after that they no longer provided a "wild" ride. Examination of the helicopter's flight control and propulsion system revealed no anomalies that would have precluded normal operation. Examination of the helicopter’s seat belt buckles revealed fatigue fracture within the buckle, which was later addressed in a Special Airworthiness Information Bulletin and the helicopter manufacturer's service bulletin.

History of flight

On September 24, 2005, about 1105 central daylight time, a Robinson R44, N9158U, operated by Midstate Aviation Inc. (Midstate Helicopters Inc.), received substantial damage on impact with a power line and Hammil Lake, near Drummond, Wisconsin, while providing rides during a Fall festival at Cable, Wisconsin. Visual meteorological conditions were recorded at the time of the accident. The 14 CFR Part 91 revenue sightseeing flight was not operating on a flight plan. The pilot and two passengers were fatally injured. The local flight departed about 1100.

A witness stated that he was walking with his father in a field when he heard the helicopter that was working the Fall festival. He heard the pitch of the helicopter change, the rpm increase, and then heard a muffled crash after which he no longer heard the helicopter rotor. The pitch change lasted for 1-2 seconds. He did not hear any sputtering of the engine. It sounded like it hit water, but he added that he never heard a helicopter crash before. He talked to fishermen at Hammil Lake who said they didn't see anything. He then took their boat and went down the lake where he saw debris and a downed power line. He first saw cushions on the lake surface and then debris protruding from the water surface. He said that the debris was actually one of the helicopter's fuel tanks, which smelled like fuel.

The witness stated that the weather was cloudy, foggy, and misty. There was no ground fog. He stated that when he was on Lake Hammil, it was gray. The clouds were about 1,000 feet above the ground and visibility was good when it wasn't raining; it wasn't raining at the time of the accident. He said that the winds were from the south.

Personnel information

The pilot held a commercial pilot certificate with a rotorcraft-helicopter rating issued December 20, 2004. At the time of issuance, the pilot reported a total airplane flight time of 32.9 hours with 29.1 hours of instruction received and a total rotorcraft flight time of 141.0 hours with 84.7 hours of instruction received. The pilot was issued a certified flight instructor certificate with a rotorcraft-helicopter rating on April 6, 2005, at a total airplane flight that remained unchanged and a total rotorcraft flight time of 214.1 hours, of which 145.8 hours was instruction received. The pilot received a second class airman medical certificate on April 25, 2005, with a total reported aircraft flight time of 260 hours.

Pilot logbooks were requested from the operator and pilot's wife both of whom stated that they did not know where the logbooks were. No pilot logbooks were received by the National Transportation Safety Board (NTSB) or FAA after these requests.

Aircraft information

The 1999 Robinson R44 helicopter, serial number 0604, powered by a Lycoming IO-540-AE1A5, serial number L-25403-40A, engine was registered to a corporation, Midstate Aviation Inc., on July 19, 2001. The helicopter and engine were last inspected during a 100-hour inspection on July 20, 2005, at an aircraft and engine total time of 1,711 hours and a Hobbs time of 1,711 hours.

Wreckage and impact information

First responders reported the helicopter was resting in Hammil Lake at a depth of about 20 feet near a downed power line. The wreckage possessed a twisted strand cable that was wrapped around the main rotor mast and was embedded in the main rotor blades, which exhibited fracture and separation. The tail boom was separated from the fuselage and the tail rotor blades did not display damage.

Both landing gear cross tubes were separated from the fuselage. The right skid tube was fractured about midpoint near the forward cross tube. The left skid tube was fractured in three locations near the forward and aft cross tubes. The right forward cross tube, near and outboard of the fuselage attachment, was missing a portion of its fairing exposing the underlying cross tube, which exhibited gouging. The aft cross tube was fractured near the left fuselage mount.

The main rotor was rotated by hand and the pulley shaft was rotated through 360 degrees. Fractures in the main rotor transmission housing exhibited granular fracture surfaces. The "Teletemp" temperature recorder strip stripe was white on 220 degrees, 230 degrees, 240 degrees, 250 degrees, 260 degrees and 270 degrees. The four main transmission pulley drive belts were intact.

Examination of the tail rotor gearbox revealed the presence of a fluid consistent with lubricant within the gear box. The tail rotor blades rotated when the input drive to the gear was rotated by hand. The tail rotor gear box chip detector was removed and noted not to contain debris. The "Teletemp" temperature recorder strip , model 110-2, had a brown discoloration on strip portions annotated 140 degrees, 150 degrees, and 160 degrees. The strip portions annotated 170 degrees, 180 degrees, and 190 degrees were white in color.

The tail rotor drive shaft was twisted at a location about 3 feet from its forward end. Fractures along the tail rotor drive shaft exhibited a 45-degree fracture surface.

The engine top spark plugs were removed and the engine was rotated by hand and then with the electrically driven engine starter. During the engine rotation, air was expelled and drawn into each cylinder and engine continuity to the accessories was noted. During the engine rotation, fluid consistent with water, was expelled from the oil filter output. A spark from each magneto lead was obtained when the magneto drive shafts were rotated.

The ignition key switch was in the BOTH position. The Hobbs meter indicated 1,789.9 hours. The cyclic friction control was in the full counterclockwise position. The control stick was moved by hand and the main rotor blades rotated about their lateral axis. Flight control continuity was confirmed from the cockpit controls to their respective control surfaces.

Medical and pathological information

An autopsy of the pilot was conducted by the Minnesota Regional Coroner's Office on September 26, 2005.

The FAA Forensic Toxicology Fatal Accident Report was negative for all substances tested.

Survival aspects

According to first responders, the pilot and rear seat passenger were located within the helicopter and the left front seat passenger was located outside of the helicopter.

The on-scene inspection of the restraint system noted fractures in the seat belt buckle release assemblies. All of the release assemblies, webbings, and reels were removed and sent to the NTSB Materials Laboratory Division for examination.

Tests and research

Letters dated August 14, 2005, and September 9, 2005 to the FAA's Minneapolis Flight Standards District Office (FSDO) and Robinson Helicopter Company regarding Midstate Aviation Inc, were received from an individual who witnessed a Robinson R44 at 500 feet AGL "coming out of an ag-turn" near Princeton, Minnesota, while providing rides. This witness continued to watch the helicopter and observed maneuvers that included pull-ups and push-overs. The witness stated that he has logged over 1,200 hours in the Robinson R44 helicopter and has attended the Robinson Helicopter Safety Course for flight instructors. The witness stated that the helicopter was being operated in a manner contrary to all safety guidelines outlined at the Safety Course and Special Federal Aviation Regulation 73.1.

The owner of Midstate Aviation Inc. stated that they have been in business providing air rides for 4 1/2 - 5 years and it was their only helicopter. This was their first time flying in the Cable, Wisconsin, area, which began on September 23, 2005. He stated that during the rides at the Cable, Wisconsin, festival, the helicopter would approach and land from the south and takeoff toward the north due to the wind. He stated the he would "hook up" the passenger seatbelts for the helicop