Overview
On 7 November 1999, a Hughes 369 D helicopter crashed in Lindlar-Fenke, Germany, during a private flight from Marl-Loemühle to Idar-Oberstein. The helicopter was destroyed by impact and subsequent fire. Both occupants, the pilot and a female passenger, sustained fatal injuries. The pilot, a British national, was also the owner of the helicopter.
Sequence of Events
The helicopter departed Marl-Loemühle at approximately 11:55 local time under visual flight rules (VFR). Shortly after, the pilot contacted Düsseldorf Information, stating his intention to climb to 3,000 ft. Over the next few minutes, the helicopter climbed to nearly 6,000 ft in coordination with the controller. At 12:22, the radar controller informed the pilot that VFR flight to Idar-Oberstein was not possible and asked if he could continue under instrument flight rules (IFR). The pilot declined and requested a radar-assisted descent through clouds (cloud breaking). The controller refused, citing the lack of IFR capability. At 12:24, the radar controller observed the helicopter turning north without coordination; the pilot confirmed his intention to return to Marl-Loemühle and again requested a radar-guided descent through clouds. At 12:30, the pilot reported icing and requested a descent to 3,500 ft, confirming he was still inside clouds. The helicopter descended to 2,500 ft without exiting clouds, then began a climb back to 3,500 ft on controller instruction. At 12:34, the pilot declared a Mayday emergency without elaboration and again requested a radar-guided descent. The controller offered radar guidance to runway 25 at Cologne/Bonn Airport and instructed a turn to 180° and climb to 3,500 ft. At 12:36, the pilot's last transmission was heard: “we are out of ....” Further attempts to contact the pilot were unsuccessful. Witnesses observed the helicopter emerge from clouds with a strong nose-down pitch and impact a meadow in Lindlar-Fenke at approximately 12:37.
Investigation
The German Federal Bureau of Aircraft Accident Investigation (BFU) conducted an on-site investigation. Technical examination of the helicopter found no evidence of pre-existing defects. Weather at the accident site (elevation about 900 ft) was described by witnesses as foggy and rainy with visibility below 1 km; hills were obscured by clouds above 60 m. Weather reports from Marl-Loemühle at departure showed visibility 7,000 m, wind 250°/9 kt, scattered clouds at 900 ft and broken at 1,500 ft, temperature/dew point 10°/10°C, QNH 1022 hPa. At Cologne/Bonn Airport, about 25 km away, conditions near the accident time were visibility 9,000 m in drizzle, wind 270°/9 kt, scattered at 900 ft and overcast at 1,200 ft, temperature/dew point 8°/7°C, QNH 1022 hPa. Radar data and radio communications were analyzed. The pilot held a valid UK private helicopter license but had no instrument rating and did not possess a US or German license required to operate a US-registered helicopter in Germany. The investigation determined that the pilot, lacking knowledge of cloud tops, decided to fly above clouds. He subsequently entered clouds and continued without instrument rating. The helicopter encountered icing conditions, leading to a flight regime the pilot could not control. The helicopter turned more than 270° without coordination, lost altitude at an average descent rate exceeding 1,300 ft/min, and impacted terrain.
Conclusions
The accident was initiated by the pilot's decision to conduct VFR flight above clouds without knowing the cloud tops. He entered clouds and continued the flight without an instrument rating. The helicopter flew into an area with icing conditions and entered a flight state that the pilot could no longer control.