Casualties unknown

2024-02-11: MQ-9A (13-4231) — Air Combat Command (ACC) — CREECH AFB

CREECH AFB, US

On February 11, 2024, a MQ-9A (registration 13-4231) operated by Air Combat Command (ACC) was involved in an aviation accident near CREECH AFB. Investigators recorded the probable cause as: The causes were: (1) the MP failed to comply with the takeoff checklist guidance to move the throttle control to 100% after initiating an ATLC takeoff, causing thrust to decrease to flight idle at the transition from ATLC to manual control; (2) the MP failed… This summary draws on records from the U.S. Air Force Accident Investigation Board (AIB); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. Air Force Accident Investigation Board (AIB)Primary reportUpdated 1781081675Data APIEditorial standards

On 11 February 2024, an MQ-9A Reaper (T/N 13-4231) crashed shortly after an automated takeoff in the AFRICOM AOR. The mishap pilot failed to set throttle to 100% as per checklist, causing power loss upon disengaging ATLC. No injuries or fatalities occurred.

Summary

On 11 February 2024, at approximately 20:32 Zulu time, an MQ-9A Reaper, tail number 13-4231, assigned to the 432d Wing at Creech Air Force Base, Nevada, impacted the ground just beyond the departure end of the runway within the United States Africa Command (AFRICOM) area of responsibility. The aircraft was destroyed upon impact, with a loss of government property valued at $25,840,037.00. There were no injuries, no fatalities, and no damage to civilian property.

Sequence of Events

The mishap crew (MC), consisting of a mishap pilot (MP) and mishap sensor operator (MSO), was conducting a launch using the Automatic Takeoff and Landing Capability (ATLC). The MP engaged the ATLC function, which commanded engine power to 100%, and the aircraft began its takeoff roll. However, the MC did not complete or communicate the next step of the TAKEOFF checklist: “22. [ATLC] Throttle – 100% (P),” which directed the pilot to manually set the throttle control to 100% to match the ATLC command. The MP's throttle control remained at 0%.

After takeoff, as the aircraft was climbing, the MP turned off ATLC via the Head-Down Display (HDD), taking manual control. This action caused the engine power to reduce to 0%, matching the manually set throttle position. The aircraft initially continued to climb and decelerate, then began to descend. It impacted the ground 23 seconds after ATLC disengagement. One second before impact, the MP increased the throttle command to 100%, but it was too late for the engine to respond.

Causes

The Accident Investigation Board (AIB) President determined, by a preponderance of the evidence, two causes: (1) the MP failed to comply with the takeoff checklist guidance to move the throttle control to 100% after initiating an ATLC takeoff, resulting in a thrust decrease to flight idle at the transition to manual control; (2) the MP failed to accurately analyze the cause of the aircraft deceleration in time and increased the throttle too late to recover from a low altitude thrust-deficient descent. Additionally, two factors substantially contributed: ineffective crew resource management and low ATLC disengagement altitude.

Aircraft and Crew

The MQ-9A Reaper was operated by the Launch and Recovery Element (LRE) from the 12th Expeditionary Special Operations Squadron (12 ESOS) assigned to Air Force Special Operations Command (AFSOC). The mishap pilot and sensor operator were deployed personnel. No pre-existing maintenance issues or system malfunctions were identified as causal.

Investigation

The AIB conducted an engineering evaluation and throttle analysis, confirming the sequence of events. A simulator re-creation demonstrated the same outcome. The investigation found that the MP's failure to follow the checklist and delayed recognition of the power loss led to the crash. No medical or pathological factors were identified.

Probable cause

The causes were: (1) the MP failed to comply with the takeoff checklist guidance to move the throttle control to 100% after initiating an ATLC takeoff, causing thrust to decrease to flight idle at the transition from ATLC to manual control; (2) the MP failed to accurately analyze the cause of the MA deceleration in time, and subsequently increased the throttle control too late to recover from a low altitude thrust-deficient descent, resulting in the aircraft impacting the ground.