The KC-46 tanker’s refueling boom has gotten stuck in at least three fighter jets during missions, resulting in three accidents and damage measured in the tens of millions of dollars, the Air Force has found.
Two of the accidents took place in 2022 and another last year, according to investigation reports released on Aug. 25.
The tanker’s “stiff boom” is just one of the program’s category 1 deficiencies. The boom’s stiffness requires more force to move it in and out of position. Boeing is working on a redesign to the boom’s actuator system and the Air Force has previously said that a fix will be ready in fiscal 2026, but the service did not confirm a timeline in time for publication.
“Challenges with adding a new aircraft to the fleet are not uncommon but we do not take these incidents lightly. We have used the lessons learned to refine our KC-46 operations, including focused training and guidance while partnering with the contractor to implement long-term solutions,” Lt. Gen. Rebecca Sonkiss, Air Mobility Command’s deputy commander, said in the press release that accompanied the reports.
The first report released by the service details a mishap on Oct. 15, 2022, when a KC-46 refueled an F-15E Strike Eagle and the boom got stuck in the jet during a breakaway. The boom then hit the tanker’s tail and caused $8.3 million in damages. The accident investigation board found that a “limitation” in the boom control system caused the operator to inadvertently place force on the boom and the nozzle became stuck in the receiver’s receptacle.
The second mishap, on Nov. 7, 2022, occurred after another “nozzle-binding” event. The investigation found that the boom operator failed to verify that the nozzle was clear of an F-22 Raptor’s refueling receptacle before making control inputs, causing the nozzle to be stuck in the fighter jet’s receptacle. The resulting damage to the nozzle cost about $100,000 to repair.
In both 2022 incidents, the investigation board put some blame on the fighter pilots, finding that they “did not consider the KC-46A stiff-boom characteristics” which “substantially contributed” to the mishap.
The third accident, on Aug. 21, 2024, occurred when a KC-46 was refueling a F-15E. The boom got stuck in the jet’s receptacle, then released with enough recoil to strike the tanker. The boom broke apart, resulting in $14 million in damages. That mishap was primarily caused by the boom operator’s control inputs, investigators found.
To prevent more accidents, the service increased the “refueling envelope”—the distance between the tanker and refueling aircraft—from six feet to 10 feet. That adjustment gives boom operators more time to “react during critical situations” and “better visual cues” of the receiver aircraft, according to AMC.
That restriction was put in place in November, after the August incident, according to an AMC spokesperson. But another accident involving the tanker’s boom happened this July—raising questions about how effective the new restriction has been.
The Air Force acknowledged in their press release that “another nozzle-binding incident” occurred in July but said it remains under investigation. “Upon completion, the command will determine if further mitigation efforts are required,” the service said.
The two 2022 accident reports also mention problems with the tanker’s Remote Vision System, another category 1 deficiency, which displays a “HI-LOAD” warning when force is exerted beyond what the nozzle can handle.
But the service has found that the warning doesn’t work “due to a lack of contrast against the imagery provided by the Remote Vision System and its placement outside the [Aerial Refueling Operator’s] direct field of view,” according to the reports.
A fleet-wide fix, called Remote Vision System 2.0, is in the works, but has been delayed for years and won’t be ready until summer 2027.
