By Thomas Clouse / The Spokesman-Review
SPOKANE — A recent government report indicates that design problems with the Air Force’s new KC-46 Pegasus tanker, which is built in Everett, could cost an additional $300 million and delay until next year the full delivery of the new airplane.
The aerial-refueling tanker is designed to eventually replace aging KC-135 Stratotankers like those based at Fairchild Air Force Base near here.
The federal Government Accountability Office said in a report released last week that continuing problems with the refueling boom on the Pegasus could inadvertently scratch fighter jets’ stealth coatings, making them susceptible to radar, according a story first reported by the Air Force Times. The problems will require some redesign.
The KC-46 is based on the Boeing 767 airframe.
The GAO report was not all bad news. Despite the $300 million cost for retrofitting the existing KC-46s, the overall cost of delivering the 179 KC-46s is now expected to amount to $43 billion, which is about $9 billion cheaper than an estimate in 2011.
But the delay could mean that Boeing will not be able to deliver nine sets of the wing aerial refueling pods until mid-2020, which is about three years later than expected, according to the Air Force Times report.
Government inspectors found deficiencies in the KC-46’s remote vision system for its refueling boom. The cameras sometimes had problems with glare from the sun at certain angles. Operators also reported having trouble seeing the receiving aircraft’s receptacles to guide in the fueling boom and depth perception problems during some lighting conditions.
Boeing said it has already made changes, which are necessary to allow crews to operate the KC-46 during all-weather and light conditions. But the redesign could take years to fix, according to the GAO report.
The design deficiencies present a problem for planes such as the F-22 Raptor, because inadvertent boom-nozzle contact from the KC-46 could scratch or damage the F-22’s special stealth coatings, possibly making them visible to radar, according to the report.
Lighter aircraft, such as the A-10 Thunderbolt II “Warthog” and the F-16 Fighting Falcon, must use more power to move the boom forward. That additional force can cause the airplanes to lunge forward upon release from the refueling boom and cause contact, which could damage both planes.
A collision of this type is particularly dangerous for A-10 pilots because the refueling receptacle on the Warthog is located on the nose and any contact with the refueling boom could damage the windshield, according to the report.
Despite the problems, the delays in the KC-46 tankers are not expected to have an impact on the role at Fairchild Air Force Base, Capt. Tanya Downsworth said.
“This is not going to affect our operations,” Downsworth said. “We are actually slated to continue operating the KC-135 for decades to come.”
Between the active Air Force units with the 92nd Air Refueling Wing and the Washington Air National Guard’s 141st Air Refueling Wing, Fairchild is home to some 48 KC-135s, which came into service in 1957 and are based on the Boeing 707 airframe.
Downsworth said that by the end of next year, which is the new deadline for the delivery of the KC-46s at other air bases, Fairchild should support 60 of the KC-135s.