What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Aircraft was operating in a large field doing fire bucket operation/training with a U.S. Forest service crew. Pilot was attempting to pick up the canvas water bucket in the unimproved field. It appears that the rear portion of the right skid dug into the soft ground as he attempted to bring the helicopter to a hover, perhaps in an unnoticed drift to the right. The pilot reported that he felt a force pulling his skid down as he attempted to hover. He recognized the problem too late as he applied full left cyclic and lowered the collective after the helicopter exceeded the critical angle of bank into the low skid. At that point the situation was unrecoverable, and the helicopter rolled 90 degrees to the right severing all control surfaces. This appears to be a classic case of dynamic rollover, which is quite common on similar skid equipped helicopters.
As the FAA filed it
(-23) AIRCRAFT WAS OPERATING IN A LARGE FIELD DOING FIRE BUCKET OPERATION/TRAINING WITH A U.S. FOREST SERVICE CREW. PILOT WAS ATTEMPTING TO PICK UP THE CANVAS WATER BUCKET IN THE UNIMPROVED FIELD. IT APPEARS THAT THE REAR PORTION OF THE RIGHT SKID DUG INTO THE SOFT GROUND AS HE ATTEMPTED TO BRING THE HELICOPTER TO A HOVER, PERHAPS IN AN UNNOTICED DRIFT TO THE RIGHT. THE PILOT REPORTED THAT HE FELT A FORCE PULLING HIS SKID DOWN AS HE ATTEMPTED TO HOVER. HE RECOGNIZED THE PROBLEM TOO LATE AS HE APPLIED FULL LEFT CYCLIC AND LOWERED THE COLLECTIVE AFTER THE HELICOPTER EXCEEDED THE CRITICAL ANGLE OF BANK INTO THE LOW SKID. AT THAT POINT THE SITUATION WAS UNRECOVERABLE, AND THE HELICOPTER ROLLED 90 DEGREES TO THE RIGHT SEVERING ALL CONTROL SURFACES. THIS APPEARS TO BE A CLASSIC CASE OF DYNAMIC ROLLOVER, WHICH IS QUITE COMMON ON SIMILAR SKID EQUIPPED HELICOPTERS.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.