What happened
On May 24, 2016, at 06:50, a Bell 47 G2 helicopter, registration F-GAMD, was preparing for an aerial spraying mission in Ampuis, France. Following a pre-flight inspection, the pilot attempted to take off directly from the aircraft's transport trailer. During the initial takeoff phase, the helicopter tipped onto its left side and struck the ground. The pilot sustained slight injuries, and the aircraft was destroyed.
The investigation
Investigators examined both the helicopter and the transport trailer, confirming that two securing straps remained attached to the left skid. These straps were oxidized and featured only faded traces of red paint, making them difficult to see. No warning devices were present to alert the crew to the straps' presence.
Testimony revealed that the previous evening, a mechanic had transported the helicopter to the takeoff site. Under rainy conditions, the mechanic worked to remove the four straps (two per skid) used to secure the aircraft to the trailer. The task was completed around 20:00. On the morning of the accident, the pilot and mechanic arrived at the site at 06:45. After the pre-flight inspection, the pilot started the engine while the mechanic checked the oil level and moved to the spraying area. Neither individual noticed that the two straps on the left skid had been left in place. The investigation also noted that the crew lacked a formal procedure or checklist for securing or releasing the aircraft from its trailer.
Findings
- The primary cause of the accident was the failure to remove two of the four securing straps from the helicopter skids.
- The lack of a standardized checklist or procedure for unstrapping the aircraft after road transport contributed to the error.
- The use of oxidized, faded straps made them difficult to distinguish from the aircraft components.
- There was no signaling device in place to alert the pilot or mechanic to the presence of the remaining straps.