The U.S. Air Force says its KC-46A tanker program recently learned that two of the plane’s systems — the Centerline Drogue System (CDS) and the Remote Vision System (RVS) – are not yet meeting performance requirements.

The CDS is a hose-and-drogue refueling system attached to the belly of the fuselage. The RVS is a camera that allows the operator to determine whether the CDS or the refueling boom is working properly. 

A KC-46A tanker is refueled by a second KC-46 for the first time, as seen from the tanker’s air refueling operator station. (Boeing photo)
A KC-46A tanker is refueled by a second KC-46 for the first time, as seen from the tanker’s air refueling operator station. (Boeing photo)

The program office was notified of the CDS and RVS “deficiencies” last week, and the Air Force is working with prime contractor Boeing [BA] to fix them, service spokeswoman Ann Stefanek said in a statement late March 14.

“Flight testing will continue to collect performance data on these two deficiencies,” Stefanek said. “The Air Force and Boeing team will continue to make refinements to address these issues.”

Boeing spokesman Chick Ramey said the company has developed a software update to improve the visibility provided by the RVS. Flight-testing of the update is to begin this month.

Boeing is also tweaking the CDS to address what the Air Force described as “unintentional receiver aircraft disconnects from the CDS.”

“We are confident that the KC-46A will meet Air Force operational needs safely and effectively,” Ramey said.

Air Force acquisition chief William Roper told the House Armed Services Committee’s seapower and projection forces panel March 14 that he is closely following efforts to fix the problems to ensure they do not delay the program. A delay could affect KC-46A training and how long the service needs to keep the aging KC-10s and KC-135s that the new tanker is supposed to replace.

“If these new deficiencies are not retired quickly, then it’s going to make me be very concerned about hitting our delivery date this year,” Roper testified. “This is a very critical year for the tanker.”

The delivery of the first KC-46A has already been delayed several times because completing flight testing and obtaining airworthiness certifications have taken longer than expected. Originally slated for early 2016, the delivery milestone is now supposed to happen late this year (Defense Daily, March 7).

The new deficiencies are not expected to affect the latest delivery schedule, which already factored in “the potential for additional technical findings,” Stefanek said.

Air Force Undersecretary Matthew Donovan, who recently visited Boeing’s KC-46A production and modification factory in Everett, Wash., said that “while Boeing has built a superb capability in the KC-46A, we need them to double down on providing the necessary resources and engineering talent to push the last 10 yards and get this program over the goal line.”

The deficiencies are not the first to arise in the tanker’s development. The Air Force said last fall that the program was working to fix glitches with the boom and the high-frequency radio.