What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The aircraft was positioned on the ramp at the air methods maintenance facility. The aircraft was undergoing some avionics adjustments by two technicians, subsequent to an unsuccessful compass swing/test flight. A third maintenance person opened the transmission cowling, left it open and left the area. The pilot was told by the avionics technicians that they had completed their adjustments. Subsequently, the pilot and the technicians attempted a take off without securing the open cowling. A few feet after lift off, a ground crew person saw the open cowling and signaled to abort the take off. The pilot descended and prior to touch down, the cowling departed the aircraft through the main rotor. This created schrapnel which caused minor damage to the tail boom, one main rotor and significant damage to the cowling. No injuries.
As the FAA filed it
(-23) THE AIRCRAFT WAS POSITIONED ON THE RAMP AT THE AIR METHODS MAINTENANCE FACILITY. THE AIRCRAFT WAS UNDERGOING SOME AVIONICS ADJUSTMENTS BY TWO TECHNICIANS, SUBSEQUENT TO AN UNSUCCESSFUL COMPASS SWING/TEST FLIGHT. A THIRD MAINTENANCE PERSON OPENED THE TRANSMISSION COWLING, LEFT IT OPEN AND LEFT THE AREA. THE PILOT WAS TOLD BY THE AVIONICS TECHNICIANS THAT THEY HAD COMPLETED THEIR ADJUSTMENTS. SUBSEQUENTLY, THE PILOT AND THE TECHNICIANS ATTEMPTED A TAKE OFF WITHOUT SECURING THE OPEN COWLING. A FEW FEET AFTER LIFT OFF, A GROUND CREW PERSON SAW THE OPEN COWLING AND SIGNALED TO ABORT THE TAKE OFF. THE PILOT DESCENDED AND PRIOR TO TOUCH DOWN, THE COWLING DEPARTED THE AIRCRAFT THROUGH THE MAIN ROTOR. THIS CREATED SCHRAPNEL WHICH CAUSED MINOR DAMAGE TO THE TAIL BOOM, ONE MAIN ROTOR AND SIGNIFICANT DAMAGE TO THE COWLING. NO INJURIES.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.