Accident Investigation Board releases report on a 412th Test Wing fallen teammate

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  • 412th Test Wing

An Air Force Materiel Command accident investigation board recently identified the cause of an MQ-9A remotely piloted aircraft accident which fatally injured Stephanie Rodriguez-Cosme, 32, of Palmdale, California. Rodriguez-Cosme was critically injured Sept. 7, 2023, when she inadvertently walked into the parked aircraft’s rotating propeller. She died shortly after being airlifted to Antelope Valley Hospital in Lancaster.

Rodriguez-Cosme was a test engineer employed by with Sumaria Systems, which has a contract with Detachment 3 of the Air Force Life Cycle Management Center to provide test support services on the MQ-9A near Edwards AFB. She previously worked with the 461st Flight Test Squadron in the F-35 Combined Test Force at Edwards AFB.

In his statement of opinion, accident investigation board president Brig. Gen. Lance French found two causes for the accident. According to French, Rodriguez-Cosme was incorrectly instructed or trained on how to take telemetry readings when approaching the MQ-9A while the engine was running, and lost situational awareness while walking around the accident with a hand-held telemetry measurement device.

French also identified two factors that substantially contributed to the mishap. There was a clear lack of communication among the contractor test team and ground support employees. Additionally, the tests conducted that day were rushed due to previous delays and cancellations.

An Air Force team replicated the accident sequence using an MQ-9 parked in the same spot, with the engine running, at the same power setting, with similar twilight lighting conditions, and with airfield ramp stadium lighting – all similar to the conditions present on Sept. 7. During the simulation, the spinning propeller was not visible when looking to the rear of the aircraft from the direction Rodriguez-Cosme had approached.

The AFLCMC Intelligence Surveillance and Reconnaissance/Special Operations Forces Directorate at Wright-Patterson AFB, Ohio, oversees lifecycle program management for the MQ-9A Reaper fleet.

The accident investigation board report is available at