Boeing Flies KC-46 Prototype with Aerial Refueling System

Boeing flew a prototype of its KC-46A Pegasus tanker for the first time with aerial refueling equipment installed on June 2. The engineering and manufacturing development (EMD) aircraft, a 767-2C “provisioned freighter” fitted with a refueling boom and wing aerial refueling pods, stayed aloft for 4.3 hours, flying from Boeing Field in Seattle to Paine Field in Everett, Wash.

The EMD-1 aircraft is one of four prototypes Boeing is developing for the U.S. Air Force requirement for 179 tankers. Two are 767-2Cs the manufacturer is using for Federal Aviation Administration certification testing; two will be “full-up” KC-46A tankers with military provisions.

Boeing plans to conduct the first flight of EMD-2, a full tanker, by late summer, followed by EMD-3, a provisioned freighter, and EMD-4, another tanker, by the end of the year. All four aircraft will eventually be converted to KC-46As.

Boeing completed the first flight of the EMD-1 aircraft on December 28 from Paine Field, months later than initially planned. It performed the second, third and fourth flights from May 28 to 30, then fitted the aircraft with an aerial refueling boom and wing aerial refueling pods (WARPs), which were not functional for the flight test. The aircraft is now undergoing a series of ground tests and will later return to flight for envelope expansion testing, Boeing said.

The KC-46A will have a fly-by-wire refueling boom based on the system the Air Force uses on the KC-10 Extender tanker, plus a centerline drogue system and WARPs supplied by Cobham. The Boeing-manufactured boom will be capable of offloading 1,200 gallons of fuel per minute; the centerline drogue and removable WARPs each have flow rates of 400 gallons per minute.