Boeing [BA], prime contractor for the Air Force’s KC-46 aerial refueling tanker, is at least two months behind schedule for first flight on its second engineering and manufacturing development aircraft (EMD-2), according to a key officer.

Air Force Program Executive Officer (PEO) for Tankers Brig. Gen. Duke Richardson said Tuesday EMD-2 was originally scheduled for first flight in January. Richardson said the Air Force completed “power on” on EMD-2 and is now working through functional test, which he said consists of tasks along the lines of making sure the boom extends properly when the correct button is pushed. 

“Making sure all the wiring is where it’s supposed to be and operating as it is supposed to,” Richardson told an audience at the Credit Suisse/McAleese and Associates conference in downtown Washington. “We’re working through that right now.”

Some good news, Richardson said, is though EMD-2 is taking longer than he’d like, it’s not taking as long as EMD-1 did.

“There’s a fair amount of learning going on, but not as much as I’d like at this stage,” Richardson said.

Richardson said the EMD-1 aircraft is currently being retrofitted with some new body fuel tanks and is ready to have a “flutter test” performed on it. Richardson called the flutter test “very important” as it is necessary for the FAA certification required to have put a warfighter on a tanker.

There are four EMD aircraft, two 767-2C variants and two KC-46s, in the tanker program. EMD-1, a 767-2C, made its first flight in late December. Boeing spokeswoman Caroline Hutcheson said EMD-2 is a KC-46 variant. The 767-2Cs enter flight test as commercial freighters before receiving their aerial refueling systems while the KC-46s will fly as fully equipped tankers through the FAA and military certification processes.

Hutcheson said Tuesday in an email the delays are Boeing’s responsibility until it delivers aircraft at what she called required assets available.

EMD runs through mid 2016 and covers all four EMD aircraft. Hutcheson said in December the second, third and fourth EMD aircraft are in mature states of build and will join the flight test program in 2015. Hutcheson said in December the goal is to deliver 18 initial combat-ready tankers to the Air Force by 2017. 

Hutcheson on Tuesday wouldn’t say when EMD-2 would fly, but said in an email Boeing is working hard every day to get ready for that first flight.

“We’re putting every ounce of effort into the program to keep it on track and moving forward,” Hutcheson said.

The Air Force did not respond to a request for comment by press time Tuesday.

The Air Force in total ordered 179 KC-46s in a contract worth potentially $35 billion (Defense Daily; Jan. 5, 2012). U.S. Transportation Command (TRANSCOM) chief Air Force Gen. Paul Selva recently called Boeing’s goal of tankers by 2017 “aggressive” and warned the program has little margin for error (Defense Daily, Dec. 4).