Boeing and the US Air Force have temporarily paused deliveries of the KC-46A Pegasus tanker after cracks were found on two aircraft slated for delivery, according to information obtained by The War Zone.
The cracks were detected on primary and secondary structures of the aircraft during pre-delivery inspections, raising fresh concerns over the troubled refueling platform’s reliability.
The discovery affected two of the four KC-46As that were set to be handed over to a military delivery center, prompting the manufacturer to halt deliveries while a thorough investigation is conducted.
“We are working closely with the customer to assess a potential issue on KC-46A aircraft and to mitigate any potential impact to the fleet and in-production airplanes,” the US Air Force confirmed.
In parallel, the Air Force announced it would inspect its fleet of 89 KC-46A Pegasus tankers already in service.
Ongoing technical challenges for the Pegasus program
The KC-46A Pegasus, designed to handle aerial refueling, cargo transport, and medical evacuation missions, is a cornerstone of the US Air Force’s strategic air mobility fleet. However, the program has faced persistent technical and quality control issues since its inception, casting a shadow over the aircraft’s operational reliability.
Even before its first delivery in January 2019, the KC-46 faced significant hurdles. The aircraft’s Remote Vision System (RVS), developed by Rockwell Collins, was found to be flawed, hampering the crew’s ability to safely guide the refueling boom. Additional defects emerged over time, including malfunctioning cargo hold fasteners, fuel leaks, and problems with the refueling boom itself.
The Air Force temporarily halted deliveries twice in 2019 after finding foreign object debris (FOD) such as tools and misplaced parts left inside the aircraft during production, which highlighted concerns over Boeing’s manufacturing discipline.
The repeated technical difficulties with the KC-46A have resulted in billions of dollars in financial charges for Boeing. As recently as January 2025, when presenting its fourth-quarter 2024 results, Boeing disclosed an additional €1.7 billion in defense-related charges, with €800 million specifically tied to the KC-46 program.
New technical issues also emerged in July 2024, when the Air Force classified a Category 1 deficiency—the most severe level of defect—due to excessive vibrations in a fuel pump, which risked damaging the engine air bleed system. This system plays a vital role in cabin pressurization and subsystem cooling. Although a short-term fix was implemented, the incident underscored the ongoing technical fragility of the platform.
With the KC-10 Extender phased out in 2024 and the aging KC-135 Stratotanker fleet gradually being retired, the US Air Force has little choice but to persevere with the Pegasus, despite its troubled development and continuing technical hurdles.
