US News

Contractor killed when she walks into Air Force drone propeller while looking down at device

A US Air Force civilian contractor was killed when she walked into a drone’s rotating propeller at a California airfield — after losing “situational awareness” while glued to a data recording device, officials say.

Stephanie Cosme, 32, was fatally injured when she “inadvertently” stumbled into the moving propeller of a parked MQ-9A Reaper drone at Gray Butte Airfield on Sept. 7, according to a new statement from Air Force Materiel Command summing up the findings of a report on the accident.

Civilian contractor Stephanie Cosme, 32, was killed when she walked into an Air Force drone’s propeller. Facebook/Stephanie Cosme

“Without looking up to determine her position relative to the aircraft, [Cosme] proceeded to walk directly into the propeller of the [aircraft] sustaining fatal injuries,” stated the final investigation report released Friday.

In his statement of opinion, Accident Investigation Board president Brig. Gen. Lance French identified two causes for the accident.

Cosme was carrying out testing on a parked MQ-9A Reaper drone at Gray Butte Airfield on Sept. 7 when the accident happened. United States Air Force

First, Cosme was incorrectly instructed or trained on how to take data readings when approaching a drone while its engine is running. 

Second, “she lost situational awareness” while walking around the unmanned aircraft taking readings with a hand-held device, the report stated.

French also singled out two additional factors that he said “substantially contributed to the mishap,” including a clear lack of communication between the contractor test team and ground support workers and the fact that the tests conducted on Sept. 7 were “rushed” because of previous delays.

Cosme, who was employed by the company Sumaria Systems, LLC, which provides test support services for the Air Force, took measurements with a power meter and then proceeded to walk toward the rear of the drone, “looking down at the testing device the whole time.

Investigators have concluded that Cosme lost “situational awareness” while walking toward the rear of the drone. Facebook/Stephanie Cosme

She also “appeared to be pressing buttons, possibly to keep the backlight on,” the report said, describing how she was “focused in on that meter.”

As Cosme inched closer to the whirring propeller, her co-workers began “shouting and waving” to draw her attention, to no avail.

After the impact, the crew chief was heard yelling over the radio, “Kill, kill, kill kill!” before one of the workers was seen on the drone’s front camera running from right to left, presumably toward the Reaper’s kill switch.

Cosme was taking data readings while the drone’s engine was running and its propellers were rotating. AFP via Getty Images

Cosme was found bleeding from wounds to her head and left arm and was unresponsive but still breathing. She was airlifted by helicopter to a hospital but died a little over an hour later.

As part of the probe into the accident, Air force officials tried to replicate the sequence of events at the same location, with a Reaper drone’s engine running at the same power settings, in the same twilight lighting conditions and under the stadium lighting as on Sept. 7.

The re-enactment led to the conclusion that the spinning propeller was not visible from Cosme’s viewpoint, and she most likely never heard anyone shouting warnings over the roar of the engine.  

The 32-year-old contractor was said to have been incorrectly instructed or trained on how to perform data collection. Facebook/Stephanie Cosme
Cosme was planning to be married. Facebook/Stephanie Cosme

Cosme of Palmdale, Calif., was described in an obituary as “a cherished daughter, sister, fiancé, mother, and friend” who “touched the hearts of everyone she encountered with her warmth, kindness, and unwavering love.”

“She was known for her passion for crafting, baking, aviation, and all things strange and unusual,” the obituary continued.

The woman was survived by her parents, two siblings, fiancé and stepdaughter.