However, the program was structured at Boeing's request to include a high level of development and testing concurrency. Company officials say this strategy is sound owing to a marriage of skills from BCA in developing the 767-2C baseline with detailed mission systems work from the Defense, Space & Security unit. Bogdan says, however, that he will not approve full-rate production until the company demonstrates performance in development.

Thus, Boeing is dedicating resources to establish several systems integration laboratories (SILs) dedicated solely to the KC-46A. Bogdan says this strategy exceeded his expectation of just one dedicated to the program.

One lab is a hardware-in-the loop SIL that includes a representative flight deck and boom-operator control station, says Jerry Drelling, a Boeing spokesman. It will also include an actual KC-46A boom in a hangar that will be used to test KC-46A control software, Bogdan adds.

The KC-46A boom design marries the outer mold line of the KC-10 boom with modern, fly-by-wire controls. This lab will be checked out by the end of June, with a full testing capability ready a year later, says Drelling.

“Before we ever start building an airplane or testing an airplane, that SIL will have 100 percent functionality relative to the software of the airplane,” Bogdan declares.

Two other SILs, slated for initial checkout by October, will focus separately on the commercial 767-2C avionics software and an integrated, military-specific suite of software for the KC-46A design. Engineers will incrementally load and test software in both labs. The mission systems lab will be fully ready for testing by October 2013.

There will also be two subsystem-testing labs—one to assess the aircraft's lighting and another “wet-fuel” facility to experiment with the entire KC-46A fuel system.

The KC-46A will be able to refuel more types of receivers than its KC-135 predecessor; these include special operations aircraft that require covert lighting, Bogdan says. The lighting lab will be checked out by the end of June, with full testing slated to start a year later. The wet-fuels lab will include a replica of the KC-46A fuel system and begin testing next year using JP8.

First flight of the first KC-46A is slated for late 2014.