Air Force: New Tanker’s First Flight Delayed by Months

KC-46A "Pegasus"

National Harbor, Md. -- Wiring problems with the Air Force's new KC-46A Pegasus tanker have delayed the highly anticipated first flights of the developmental refueling aircraft by several months, service leaders said Tuesday.

The first flight of the KC-46A baseline test aircraft has been delayed from this past August to late November. Plans for the first flight of actual KC-46A variant will slide from early 2015 to April 2015, said Air Force Maj. Gen. John Thompson, head of the Air Force tanker programs.

Thompson explained at the Air Force Association's Air & Space Conference that Boeing engineers discovered that redundant wiring systems were placed too close together in the aircraft.

"Wires that represent redundancies cannot be put next to each other in the same bundle. Another bundle needs to be placed in a different physical location somewhere on the aircraft - so that if one gets taken out you don't lose that weapons system," Thompson explained. "The FAA process identified some anomalies in some of the aircraft wiring systems."

The KC-46 is engineered with 120 miles of wiring for on-board mission systems. The wiring problems impact about 350 wire bundles of the tanker's roughly 1,700 wire bundles on board the aircraft.  

Air Force and Boeing engineers are now working on re-wiring parts of the aircraft to ensure that the aircrafts computers, weather sensors, mission systems and radar warning receivers are properly protected if wiring in one area malfunctions or is destroyed, Thompson said.

"Boeing has been redesigning those bundles and re-installing wiring," he added.

Thompson emphasized that, while the circumstance was disappointing, he did not regard the wiring issue as a major setback for the program.

"We don't see any great concern. We are confident Boeing has fixed the issues and will recover the program. It is very basic production design work. The mistakes were caught early in the program," Thompson said.

Low Rate Initial Production, or LRIP, is slated for September of next year, he added.

The Air Force's multi-year tanker procurement effort, regarded and protected as a high priority from service and Pentagon leaders, is described as a needed asset to replace the aging current fleet of tankers. The average KC-135 is about 50 years old and the average KC-10 tanker is roughly 29 years old, Thompson said.

The 165-foot KC-46A is being built with Pratt and Whitney engines and the ability to transport up to 212,000 pounds of fuel and 65,000 pounds of cargo. The aircraft will bring an improved ability to conduct aerial refueling missions, Thompson said.

For instance, the new tanker will be able to refuel aircraft via the probe and drogue while also using a boom and receptacle on a single mission.

Thompson explained that the 767s are being engineered and manufactured with some military specifications in mind to prevent the need to strip down the aircraft and fully re-configure it for military use, as has often been the case with prior Air Force aircraft acquisition efforts.    In total, the service plans to acquire as many as 179 new tankers, with the first delivery of eight aircraft slated for March, 2017, Thompson added.

The KC-46A is engineered with a centerline drogue system that can transfer 400 gallons per minute and a boom that can move up to 1,200 gallons per minute, he said. It is also configured for aeromedical evacuation and has a reconfigurable cargo deck floor able to carry up to 58 passengers. 

Like other Air Force planes, the KC-46A is engineered with a radar warning receiver, cockpit armor, VHF satcom radios, Link 16 and digital displays, Thompson said.

The cockpit is built with 24-inch 3D, digital displays equipped with touch screen capability. The aircraft enables crew members a 185-degree field of view and has low-wave infrared cameras.

The testing of the first developmental aircraft will also measure the aircraft's rate to climb and rate to descend, Thompson added in a prior interview with    Thompson cited the total program cost of the KC-46A at $50 billion, and cited $4.9 billion as a liability cap for the individual cost per plane. If the cost exceeds $54.9 billion, Boeing will be responsible to pay for the cost overages.

"The government's financial liability is capped so long as we maintain our requirements as they currently exist," he said. 

The new tanker will be used in the same strategic way that current tankers are deployed, meaning it will be forward stationed at strategically vital locations around the globe to increase mission length and effectiveness, as needed, for a wide-range of aircraft, Thompson said.

The KC 46A will refuel F-22s, F-15s, F-16s, F-35s, C-17 and KC 10s, among others, he added.

-- Kris Osborn can be reached at

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