A Weak Link

A combination of human error and signal problems caused an MQ-1B Predator to crash while taking off from a US Central Command base in April 2015, Air Combat Command investigators found. The remotely piloted aircraft was assigned to the 432nd Wing at Creech AFB, Nev., but was operated by the 20th Reconnaissance Squadron at Whiteman AFB, Mo., and deployed to an air base in CENTCOM’s area of responsibility when it veered off the runway and onto uneven ground, losing its landing gear and tails, according to the abbreviated investigation report. After linking up with the RPA on the default “wake-up” frequency, the pilot did not follow standard procedure and switch to the assigned operating frequency. The crew did not realize it, but the ground data terminal transmitter was operating in a significantly degraded state even though it was able to control the RPA while on the ground. While the aircraft was taking off, two other ground data terminals were operating on the same or similar frequency, creating a cluttered environment. The aircraft then drifted left while still on the runway and the pilot attempted to correct its path by increasing right rudder inputs. But at the same time, the signal was lost, and the RPA attempted an autonomous takeoff. The crew was alerted to the lost link, but a sensor operator was slow to execute the critical action procedure that is designed to keep uplink commands from interfering with the RPA’s lost link profile. During the delay, the signal was briefly restored, and the right rudder command was transmitted, steering the RPA toward the right edge of the runway. The RPA attempted another autonomous take off after another signal loss, but could not overcome the angle leading it off the runway because the nose gear was in the neutral position. The aircraft was unable to reach takeoff speed once off the runway. The damage to the RPA was an estimated $4.66 million. There were no fatalities or damage to private property.