The U.S. Air Force has set September 25 as the date it expects the new KC-46A tanker to fly for the first time. The maiden flight of the Boeing 767 derivative fitted with aerial refueling equipment has been delayed by several months because of technical problems with the tanker development program that have caused Boeing to twice declare charges against its books.

Speaking on September 15 at the Air Force Association Air & Space conference in National Harbor, Md., Brig. Gen. Duke Richardson, the service’s executive officer for tankers, provided the customer’s perspective on the program. “We are definitely struggling with schedule, but I can tell you we are not struggling with performance,” he told the audience.

The KC-46A engineering and manufacturing development (EMD) 2 aircraft, the first “full-up” tanker of four prototypes Boeing is building, recently completed fuel-system testing on the ground and was undergoing pre-flight checks, Richardson said. The service’s plan is to fly it later this month with its full mission equipment: a fly-by-wire refueling boom, a centerline drogue system and wing aerial refueling pods.

Boeing conducted the first flight of the EMD 1 aircraft, a baseline 767-2C “provisioned freighter,” from Paine Field in Everett, Wash., last December. It flew the aircraft with a representative aerial refueling system in June. Now at 151 flight hours, EMD 1 has completed initial airworthiness and flutter testing, and is undergoing Federal Aviation Administration certification testing, Richardson said.

The development program has been slowed, however, by wiring and other technical issues. More recently, Boeing stopped work for 30 days when a mislabeled chemical damaged the EMD 2 aircraft’s fuel system during ground testing.

Working under a $4.4 billion fixed-price incentive EMD contract the Air Force awarded in 2011, Boeing is responsible for cost overruns from the development program. The manufacturer has vowed to deliver 18 tankers to the Air Force by August 2017, as the contract requires. It declared after-tax charges of $272 million and $536 million, respectively, in July 2014 and July 2015 because of KC-46A issues.

First flight of the full-up tanker is the program’s next major milestone as it marches toward a “Milestone C” decision by the Air Force to begin low-rate initial production (LRIP). “Our plan right now, on the second flight, is to unstow the boom and see how it flies within the Milestone C envelope,” Richardson said. “Shortly thereafter, we’ll unreel the drogue systems and see how they’re doing.”

After initial flight testing, the EMD 2 aircraft will return to the fuel dock to complete ground testing of its aerial refueling system, Richardson said. This will be followed by free air stability testing, during which the tanker will fly with refueling equipment deployed to demonstrate its ability to refuel different types of aircraft, including the F-16, C-17, F/A-18, A-10, AV-8B and a receiver KC-46A.

The refueling exercise involving different aircraft is the biggest piece of the overall Milestone C demonstration effort, and once completed, “a lot of the risk will be burned down on the program.” Richardson said.

The service’s schedule calls for a Milestone C decision in April 2016, leading to an LRIP 1 contract award for seven KC-46A tankers in May and LRIP 2 award for 12 tankers in June. But another problem looms for the program if Congress fails to pass a Fiscal Year 2016 budget and instead approves a temporary continuing resolution (CR) as now expected. A “CR” would restrict spending to FY2015 levels.

“If we get into a CR situation, this will create a very large problem for this program,” Richardson warned. “We can’t go above Fiscal Year 2015 quantities, and I don’t have a contract that says I can award seven [LRIP] aircraft. That’s a problem that we need to fix.”