What happened
On November 6, at 2236 mountain standard time, a General Atomics Predator-B MQ-9 unmanned aircraft, registration CBP113, was conducting a training evaluation mission at Libby Army Airfield in Sierra Vista, Arizona. The flight was performing a sequence of touch-and-go landings on runway 26. While the initial landings in the session utilized the fixed nose camera, the third landing attempt utilized the Multi-Spectral Targeting Ball (MTS-B) payload camera.
During this third landing, the aircraft touched down on the nosegear and began to porpoise. Data indicates the flare was initiated closer to the runway and with less of a nose-up attitude than previous attempts. The aircraft bounced and contacted the runway four times, with the magnitude of the bounces and pitch excursions increasing with each impact. The pilot attempted to initiate a go-around, while the evaluator pilot simultaneously attempted to correct the bounce by pulling the control stick aft; however, the aircraft pitch continued to trend downward. The nosewheel eventually fractured, causing the aircraft to slide and resulting in damage to the payload ball, the vertical stabilizer, and the propeller.
The investigation
The investigation examined the aircraft's nosewheel, which showed no evidence of pre-existing damage or fatigue. Video recordings from the ground control station were analyzed to compare the visual perspectives between the fixed nose camera and the MTS-B camera. Additionally, an animation was created using data logger software and on-scene documentation to visualize the sequence of events.