2010 Robinson R44 collision at Altena-Hegenscheid

Accident overview and flight details On 29 January 2010, a Robinson Helicopter Company R44 Raven I helicopter, serial number 1603, was involved in an accident at Flugplatz Altena-Hegenscheid. The aircraft, built in 2006 and powered by a Lycoming O-540-F1B5 engine, had a maximum takeoff mass of 1,089 kg and was operating at approximately 967 kg at the time of the accident. It had been fully fueled before departing from Sömmerda at 14:55 local time with the pilot and two passengers aboard. The pilot had stated Krefeld as the intended destination. ## Sequence of events Witnesses near Altena-Hegenscheid observed the helicopter circling at low altitude. The pilot reported that he was searching for the airfield but could not identify it or establish radio contact. He then made an off-field landing on a snow-covered meadow to ask a person shoveling snow for directions. A passenger seated front left exited, and the local resident entered the helicopter. The aircraft then proceeded to Altena-Hegenscheid. According to witnesses and the pilot, the helicopter flew along runway 24 toward the control tower to land in front of it. The occupants reported that the cockpit windows began to fog on the inside. Shortly before reaching the tower, the pilot activated the heating system. The windows then fogged completely and suddenly, and the pilot instructed the other occupants to open the doors. At approximately 17:20, the helicopter collided with the control tower and an adjacent garage. The wreckage came to rest on its left side in the snow in front of the building. The three people aboard were able to leave the wreckage under their own power. ## Injuries and damage One person was seriously injured and two were lightly injured. The helicopter was heavily damaged, and there were also field and building damage. No fire occurred. ## Aircraft and pilot information The pilot was 41 years old and held a private pilot license for helicopters (PPL(H)) under JAR-FCL 2, first issued on 5 August 2009 and valid until 5 August 2014. He held type rating authority as pilot-in-command for the R44, valid until 5 August 2010, and a Class 2 medical certificate. The pilot reported approximately 183 hours of total experience on the R44. The state aviation authority reported about 46 hours during training before the examination, and the aircraft’s onboard documents showed about 41 hours after obtaining the license. The pilot’s personal logbook was lost in the accident. The helicopter’s total operating time was 1,370.1 hours. The last 50-hour inspection was performed at 1,330 hours, and the last airworthiness certificate was issued on 31 August 2009. The R44’s heating system uses a heat exchanger around the engine exhaust, with airflow provided by the engine cooling fan. ## Weather and navigation On the day of the accident, a shallow low-pressure system with a warm front moved across the region. High front clouds were common, with cloud bases between 1,500 and 2,500 ft. Light to moderate snow, sometimes snow showers, occurred, with cloud bases sometimes lowering to 200–500 ft. Mountainous areas were in cloud. The flight route from Sömmerda to Altena-Hegenscheid passed through GAFOR areas 24, 43, and 36. The GAFOR forecast indicated X-Ray conditions along the route, meaning ground visibility below 1,500 m and/or cloud bases below 500 ft. Area warnings for snowfall were in effect for all three GAFOR areas. At Altena-Hegenscheid, there was a continuous snow cover about 30 cm deep. Witnesses described the weather as misty with light snow at the time of the accident. Sunset in the area was at approximately 17:13. The helicopter was equipped with a fixed Garmin GNC 420 GPS. Krefeld was entered as the destination in the “Direct to” menu, and the last stored GPS coordinate was Altena-Hegenscheid. ## Airfield and recording equipment Altena-Hegenscheid (EDKD) has a 600 m grass runway oriented 06/24. The airfield elevation is 1,552 ft MSL. During the winter half-year, operations are by prior permission required (PPR). No air traffic controller was present, and no PPR request had been made for the day of the accident. The helicopter was not equipped with a flight data recorder or cockpit voice recorder, and these were not required. The GPS had not stored a flight path. Radar reconstruction was not possible; the air navigation service provider recorded neither a secondary/transponder signal nor a primary target, and suspected the helicopter was flying too low for radar tracking. ## Findings at the accident site Due to the weather, the BFU investigator reached the wreckage the following day, when documentation was complicated by snow-covered and inaccessible parts. The helicopter was on its left side about one meter in front of the control tower entrance. The cockpit glazing was broken, the instrument panel was torn out, and the main rotor blades were bent or broken in multiple places. Pieces of the main rotor were found away from the main wreckage. A control rod was broken off the rotor head. The tail boom was dented and partially torn, and the tail unit, detached from the boom, lay between the helicopter and the tower entrance. The tail rotor was on the garage roof. Impact marks were found on the control tower below the walkway, on the garage roof, side wall, gutter, and downpipes. ## Operator and additional information The helicopter’s owner held a permit from the Thuringian State Administrative Office for “non-commercial carriage of passengers for compensation,” valid until 31 December 2010. The pilot was listed as an authorized pilot for such flights. The permit was based on an expert report for a Beechcraft Super King Air 200 used in works transport. The owner advertised services on the internet, including sightseeing, charter, and film/photo flights, with terms and costs. The BFU asked several German commercial R44 operators and the manufacturer about the sudden window fogging reported by the occupants. All stated that the R44 heating system worked well and effectively protected the windows from fogging, and none had observed sudden fogging. The manufacturer was not aware of similar incidents. The maintenance company reported an incident on 15 January 2010 in which the windows suddenly fogged during the first hover after the helicopter had been stored outdoors for several weeks. It was assumed that moisture had accumulated during the long outdoor storage and was vaporized by the heating system, condensing on the cold windows. ## Assessment The pilot had held a helicopter license for about six months and had relatively limited total experience. However, he had a good training status, having flown a relatively large number of hours after obtaining the license in a short period. Flying in winter conditions and taking off and landing on a continuous snow cover were probably new to him. His experience with flights in reduced visibility and snowfall was likely limited. The pilot had no local knowledge and had not previously flown to Altena-Hegenscheid.