Primary finding
Probable cause
The flight control system’s unanticipated transition to takeoff abort mode due to a software error in the autonomous flight control system, which resulted in a premature throttle reduction and hard landing.
Investigator assessment
Analysis narrative
A Pyka Inc. unmanned aircraft system (model name Pelican, type: airplane) sustained substantial damage during a flight test at the manufacturer’s test site. There were no injuries. The airplane was operating with an FAA Certificate of Authorization No. 2025-WSA-562-SAC-REV1 and operating exemption No. 23028. According to the manufacturer’s website, the airplane is designed for agricultural spraying applications. It has 4 electric motors that each drive a two-bladed fixed-pitch propeller, and has a maximum gross weight of 1,320 lbs. Figure 1. Photo of the Pelican vehicle. (Source: Pyka Inc.) According to the operator, the purpose of the flight was to test landings. Following a normal takeoff in autonomous mode, approximately two seconds into the flight, the ground control station operator issued a land command. In response, the aircraft unexpectedly reduced throttle to idle and annunciated that it had entered a takeoff abort mode. The aircraft then descended and landed abruptly on the dirt runway. The impact resulted in partial separation of the forward fuselage at the wing leading edge and buckling of the aft fuselage on the right side beneath the wing trailing edge. After the accident, the operator discovered an error in the autonomous software that resulted in the unintended behavior of the airplane.