Boeing and Air Force work on solutions for new KC-46 tanker design flaw

The KC-46 tanker program, which has faced a series of high-risk design flaws, is encountering new challenges.

The Air Force and Boeing have discovered a new deficiency in the KC-46 tanker, identified this spring, which is causing damage to the aircraft’s air system ducts, Caliber.Az reports citing the foreign media.

This issue adds to the ongoing list of unresolved, high-risk design flaws associated with the KC-46.

Designated as a Category 1 deficiency due to its severe risk and operational limitations, the problem involves a malfunctioning fuel pump. Boeing detected that vibrations from the faulty pump were causing significant damage to the air ducts in the KC-46’s bleed air system.

Kevin Stamey, the Air Force’s program executive officer for mobility and training aircraft, informed reporters on Tuesday that Boeing has swiftly addressed the damage caused by the KC-46’s faulty fuel pump. The company is currently testing a temporary workaround to mitigate the issue, with plans for a longer-term design solution underway. Stamey indicated that this ongoing mitigation effort might lead to the deficiency being downgraded to a lower risk category in the near future.

“We potentially have a path to downgrade that as we work toward a permanent fix,” Stamey said during a media briefing at the Air Force’s Life Cycle Industry Day conference in Dayton, Ohio. “The mitigation is designed to minimize the damage caused by the vibration.”

In addition to this issue, the Air Force and Boeing are addressing seven other Category 1 deficiencies. Col. David Hall, the senior materiel leader for the program, noted that three of these deficiencies are nearing resolution.

Among the notable issues with the KC-46 tanker is the remote vision system (RVS), a critical camera system used for aerial refueling operations. After experiencing years of delays and multiple redesigns, the Air Force approved a new version, RVS 2.0, in 2022. This upgrade aims to resolve image distortion and shadowing problems present in the original system.

However, the delivery of RVS 2.0 has been pushed back from this year to 2026. According to Stamey, a recent schedule risk assessment now targets spring 2026 for its delivery.

Additionally, Boeing is working on redesigning the tanker’s boom actuator to ensure compatibility with the A-10 aircraft. Prototype hardware for this fix has been completed, with lab testing commencing in May.

Under its development contract with the Air Force, Boeing is responsible for addressing most of the Category 1 deficiencies identified before the program’s initial operational test and evaluation concludes. The company has accumulated over $7 billion in costs related to KC-46 design and manufacturing issues.

When asked about potential concerns that the current development issues might signal future production challenges, Stamey expressed confidence in Boeing's quality management efforts.

“To their credit, Boeing is proactive when it comes to addressing quality issues,” he said. “They’ve increased their inspections on the production line and are very responsive to any issues that arise.”