EVERETT — Space and time limited what I could put into my story on the KC-46 aerial-refueling tanker program update, so here are some odds and ends that I had to leave out.

The tanker is based on the 767-200ER airplane, but it includes aspects of the 767-300 and -400, as well as a cockpit based on the 787.

Boeing is getting a bare-bones version ready to fly later this month — Dec. 27 or 28. That plane is the first of the program’s four test planes. It will be a 767-2C, a new airplane type that lacks any of the military features that will be on the KC-46.

The Air Force’s Brig. Gen. Duke Richardson said 23 functional tests will still have to be finished after the first 767-2C flight.

The 767-2C is an interim version being developed to allow certification testing to get underway while the first military version is still being assembled.

The first KC-46 is set for first flight in the second half of April.

Boeing workers are still reinstalling wiring bundles on that plane, the second of the four in production. Richardson said it is about 78 percent finished.

He said he doesn’t expect many more delays — if any — from rewiring work, which caused much of the delays so far. “Of the wiring they have redesigned and reinstalled, it’s working out really well.”

Tanker test flights this summer will include items that the Pentagon will consider in September when it has to decide on whether to give Boeing the green light for full production. The Air Force has ordered 179 tankers worth an estimated $51 billion.

“There’s a little bit of flex built into the summer” schedule, he said.

The Air Force does expect to find some wrinkles during test flights, but most of the airplane’s components are mature technology, so these issues should be minor, he said.

For example, the KC-46 will use the boom used on the KC-10, the Air Force’s biggest tanker. But the control system software is different, and the operator controls the boom from video displays at a station by the cockpit. In earlier tankers, the operator has controlled it from the tail using his own eyes.

“It’s been done” before, such as on the Italian Air Force’s tanker, Richardson said.

Software integration has gone fairly smoothly with only a 4 percent increase in code, he said.

Dan Catchpole: 425-339-3454; dcatchpole@heraldnet.com; Twitter: @dcatchpole.