CEN23FA183 · Robinson R22 Beta

Although there were no witnesses to the crash, it is likely that the non-certificated pilot was conducting an engine ground run when the helicopter inadvertently became airborne. The helicopter impacted the terrain about 70 ft from the concrete pad used during ground operations. After the crash, the collective friction control was found off, which likely resulted in an unintended increase of the collective control to a point where the helicopter became airborne.

The pilot’s logbook contained a student pilot certificate; however, it expired more than 50 years before the crash. A review of the pilot’s logbook did not reveal any flights after he received a 90-day solo endorsement for a single-engine airplane in 1971, nor did it reveal any flights completed in a helicopter. The pilot had served in the US Army but in a non-pilot role.

The pilot purchased the helicopter in March 2016 as an investment and family members could not recall the last time he flew the helicopter. One of the pilot’s daughters reported that he would occasionally bring the helicopter out of the shed to perform an engine run and, on multiple occasions, he forgot to engage the collective friction control, which resulted in unintended movement of the helicopter on the ground while the engine was running.

The 93-year-old pilot’s medical history was significant for impairing physical and mental conditions. There was documentation of a previous stroke and Parkinson’s disease that impacted the strength and function of his left and right upper extremities. During his last hospital admission, about 4 months before the crash, the pilot was diagnosed with moderate senile dementia. The pilot’s postmortem toxicology results detected central nervous system depressant medications, including gabapentin and cyclobenzaprine, both of which can adversely interact with one another and worsen impairment, especially in older adults. The pilot’s baseline ability to operate the helicopter is uncertain. Regardless, it is likely that some combination of the pilot’s various physical and mental conditions and his use of potentially impairing medications contributed to the circumstances of the crash.

Ethanol was detected in blood, but not in vitreous fluid or urine. Other volatiles, n-butanol and n-propanol were also detected. It is likely that some, or all, of the detected ethanol was from postmortem production. Thus, it is unlikely that ethanol contributed to the crash.

Verbatim NTSB analysis and probable cause from the NTSB dataset