Boeing’s KC-46 tanker successfully refueled a Fairchild Republic A-10 last week, allowing the company to move toward low-rate initial production as early as next month, the US Air Force announced on 19 July.

The 15 July A-10 refueling marked the last of six demonstrations the KC-46 programme needed to fulfill before requesting approval from the Pentagon’s top acquisition official, Frank Kendall, to award production Lots 1 and 2. During the 4h flight test, the tanker offloaded 680kg (1,500lb) of fuel to the A-10 at 15,000ft.

KC-46 refuels A-10 640

Photo: Boeing

Boeing completed previous demonstrations with the US Navy’s F/A-18 and AV-8B using the centreline and wing drogue systems and the KC-46 as a receiver aircraft, the Air Force says in a 19 July news release. The company also completed refueling demonstrations on the C-17 airlifter and F-16 using the aerial refueling boom.

The latest demonstration validates Boeing's recent hardware-based solution after finding higher than expected axial loads on the refueling boom. Boeing inserted two bypass valves in the fly-by-wire-controlled boom to relieve the aerodynamic pressure. That discovery delayed the low-rate initial production decision from June to August.

The Air Force expects low rate initial production, which will include 19 aircraft total in Lots 1 and 2, to begin next month.

Boeing is under pressure to deliver 18 KC-46 by August 2017, allowing the USAF to declare initial operational capability on schedule. The first batch of deliveries will not include a capability to refuel aircraft using the Cobham wing aerial refueling pods (WARPs), which Boeing now plans to deliver a year later in 2018.