What happened
On October 1, 2025, at approximately 09:58 mountain standard time, an MK30 unmanned aircraft system (UAS), registration N791PA, was involved in an incident near Tolleson, Arizona. The aircraft was operating as a Part 135 non-scheduled cargo flight.
According to the crane operator, a Link Belt ATC-3275 mobile crane had been erected at a jobsite between 07:30 and 08:00 that morning. At 09:49, the operator felt an impact on the crane boom, which was identified as a UAS strike. While the operator was evaluating the first strike, a second UAS impacted the stationary crane. The crane was at an estimated height of 197.3 feet above ground level (agl) at a 2/5 degree angle, with the impacts occurring between 150 and 165 feet agl.
Flight track data for the UAS showed that the aircraft activated at 09:40:10 and performed flight checks. At 09:56:25, the aircraft departed from the operator's package delivery center on a northern heading. After turning east at 1,206 feet mean sea level (msl), the aircraft descended from 1,218 feet msl to 1,073 feet msl. Contact with the aircraft was lost at 09:58:08, approximately 160 feet east of the crane's location.
First responders arrived to find that the collision had caused a battery fire. The aircraft was found on the ground with damage to the fuselage and wings, though two electric wing-mounted motors remained attached to their mounts. There were no injuries resulting from the incident.
The investigation
Examination of the accident site confirmed the UAS came to rest near the crane. The battery had ejected from the aircraft and ignited. The crane inspection revealed no structural damage to the crane itself, though paint transfer from the UAS was noted.