A pair of new accident investigation board reports demonstrate how easily a simple mission can go wrong. In the span of five days last August, members of the 20th Special Operations Squadron at Cannon Air Force Base, N.M., caused accident damage in excess of $2 million each.
Investigators faulted crew members for both crashes, which included a botched parking job at Inyokern Airfield, Calif., and an accidental engine shutdown that led to an uncontrolled rapid descent and crash at Melrose Air Force Range, N.M. Neither crash appared to be systemic, a relief to supporters of the Osprey, which has been under increased scrutiny following a series of deadly mishaps in recent years.
Inyokern Airfield
The first incident took place Aug. 17 at Inyokern, near Naval Air Weapons Station China Lake, when the copilot maneuvered too close to another CV-22 nearby, causing the rotors of the two planes to collide.
During the exercise, the squadron’s CV-22s parked on an apron at one end of a runway with sufficient space for four aircraft and enough width to allow them to maneuver, investigators found. But the parking apron was deteriorating, and ground crew assigned to marshal the aircraft reported that loose concrete and dirt was getting blown into them by the CV-22’s rotors. Rather than stand where debris might hit them, the ground crew gave up their marshaling position and put one Airman behind the aircraft and another alongside.
Parking the aircraft, the copilot did not pull enough forward before backing up alongside a stationary CV-22. That put his aircraft on a path collide with the parked Osprey.
Ground crew members said they signaled for the aircraft to stop, but investigators found that the ground crew failed to use standardized language or signals throughout the deployment, creating a false sense of security for aircrew. They also were not using the daylight-fluorescent wands required. The signals were missed, ignored, or not understood.
The two aircraft’s rotors collided, destroying blades on both aircraft, and when one ground crew member dove for cover from debris, the Airman sustained a shoulder injury and concussion. Total estimated damage: $2.5 million.
Investigators cited two main causes of the accident: First, the copilot failed to ensure adequate clearance before starting to park, and second, the aircraft commander failed to tell the copilot to stop, despite feeling “uncomfortable” with how close the two aircraft were getting.
Officials also blamed mission planners for failing to mention the “congested aircraft parking area, non- standard reverse taxi requirements, deteriorating concrete conditions, and lack of ramp illumination,” all of which were potential hazards. They also faulted an overall sense of complacency, the ground crew’s failure to use standardized signals throughout the exercise, and poor oversight by squadron and group leadership, as they did not receive a brief from the mission commander.
Melrose Air Force Range
Less than a week after the California incident, a 20th Special Operations Squadron flight engineer unknowingly caused his Osprey to crash in New Mexico when a cable connecting a battery pack to his night vision goggles got looped around a lever and inadvertently switched off one engine.
The Osprey slammed into the ground, causing $2 million in damage. The incident occurred at Melrose Air Force Range, N.M., during nighttime training on Aug. 22, 2023. The flight engineer “struck his head” upon impact and was treated at a local hospital, but there were no other injuries.
According to the accident investigation report, the Osprey crew was on a training sortie for the 27th Special Operations Wing and flight engineers had just completed aerial gunnery training. The Osprey was hovering about 190 feet above the ground, and the aircraft commander and copilot were preparing to switch from hover to forward flight.
As they retracted the landing gear, the flight engineer entered the cockpit “with significant slack” in his night vision goggle battery pack cable, the report notes. Sitting down in the designated flight engineer seat, he did not notice his cable get wrapped around the right engine control lever, pulling it from “FLY” to “OFF.”
With the engine shut down, the aircraft lost the necessary power to maintain a hover and began plunging toward the ground at up to 1,500 feet per minute. The copilot tried to command full power from the aircraft, but the single engine could not generate enough lift.
The aircraft commander was able to pull the nose up to arrest the aircraft’s forward speed and slow the descent rate slowed to 800 feet per minute, but in just 11 seconds the Osprey struck the ground at a speed of around 40 knots. When the aircraft bounced—the looped battery pack cable pulled in the opposite direction, this time shifting the lever back to “FLY.” After a second, harder landing, the CV-22 slid about 360 feet.
“The antennae, lights, nose landing gear doors, and the Forward-Looking Infrared (FLIR) turret positioned on the bottom of the [aircraft] were crushed, destroyed, and spread along the skid path,” the report states.
The FLIR turret “provides a thermal image that enables a pilot to take-off, navigate at low altitudes and land in total darkness,” the report added.
The flight engineer whose cable turned the engine off was unrestrained during the crash, his head and neck “yanked backwards to the extreme of flexion and extension” by the battery cable, until it snapped, slamming his face into the center display.
The engineer was transported to a local hospital out of concern that he had suffered a concussion and released early the next morning.
Air Force investigators determined the main cause of the crash was the battery pack cable, but also faulted the aircraft commander for failing to protect the engine control levers, even though other experienced CV-22 aviators knew that pilots often guard the levers when anyone in the cockpit is getting in a seat while in flight.
On top of that, the report faulted the aircrew’s inattentiveness during a critical phase of flight and lack of real-time risk assessment. The flight engineer should not have tried or been allowed to get into the seat while the aircraft was transitioning from hover to forward flight, and the aircraft commander could have noted the wind conditions while hovering—by moving the aircraft away from a tailwind, investigators said, the aviators could have been able to recover once the mishap began.
Finally, the investigation found a lack of clear procedural guidance for how to deal with excess cable from night vision goggles, leading to the slack on the flight engineer’s cable.