A devastating accident at a California Air Force base last September has been determined to be the result of human error and lack of proper safety protocols, according to an official report released on Friday. Stephanie R. Cosme, a 32-year-old civilian test engineer, lost her life after inadvertently walking into the spinning propeller of a parked military drone during a ground test.
The harrowing incident occurred on September 7, 2023 at Gray Butte Airfield, where Ms. Cosme was employed by defense contractor Sumaria Systems to provide testing support for the Air Force Life Cycle Management Center. She was critically injured when she unexpectedly entered the arc of the propeller blades while focused on equipment readings.
Despite frantic attempts by colleagues to alert her to the danger, the report states Ms. Cosme failed to maintain proper “situational awareness” of her surroundings. Tragically, she succumbed to the catastrophic injuries shortly after being rushed to a nearby hospital.
The Air Force accident investigation board identified two primary causes of the fatal mishap. First, Ms. Cosme did not receive adequate instruction on safely taking telemetry readings from the weapons payload with the aircraft engines running. Secondly, her attention became so fixated on the data collection that she lost track of the active propeller hazard.
However, the report highlighted additional contributing factors that allowed such a preventable tragedy to occur. It cited “a clear lack of communication” among the testing team and ground crew, as well as a rushed operational pace due to prior test delays and cancellations on that fateful day.
“Without looking up to determine her position relative to the aircraft, [Ms. Cosme] proceeded to walk directly into the propeller…sustaining fatal injuries,” the report stated, adding that bystanders desperately tried to wave her away but it was too late.
Born in Fontana and raised in Palmdale, California, Stephanie Cosme is being remembered as a warm, caring person who brought joy to those around her. Her obituary lauded her “innate ability to make those around her feel special and valued” and noted that “her gentle spirit and radiant smile brought comfort and joy to all who had the privilege of knowing her.”
“The loss of Stephanie leaves an irreplaceable void in our lives, but her spirit will live on in the hearts of all who were fortunate enough to know her,” the tribute lovingly stated.
Unfortunately, tragic propeller accidents are not isolated incidents. Just last month, a 3-year-old boy died after falling off a boat and being struck by the spinning blades in a horrific accident off the Florida coast. In 2022, a Texas airport worker was killed in a similarly gruesome incident after being “ingested” into a jet engine.
Safety experts say maintaining strict protocols and situational awareness are critical when working around operating machinery with exposed spinning components. Even a momentary lapse can lead to catastrophe, which underscores the need for constant vigilance, proper training, and clear communication among all personnel.
The Air Force report did not disclose if any disciplinary actions would be taken in the wake of Ms. Cosme’s death. However, the findings highlighted the need for a comprehensive review of safety procedures during hazardous operations to prevent similar future tragedies.
For her loved ones, including her parents, siblings, fiancé and stepdaughter, the grievous loss of Stephanie at just 32 years of age will be a wound that never fully heals. But her remembered warmth, kindness and love for others will be the enduring legacy of a bright light extinguished far too soon.
In a statement, the US Air Force expressed “highest condolences” to the Cosme family, adding it “remains committed to preventing similar accidental losses through strengthened operational safety measures arising from lessons learned in this heartbreaking mishap.”
