The next year will be critical for the Air Force’s KC-46A aerial refueling tanker program as it enters a challenging software phase, according to the Government Accountability Office (GAO).

GAO said in a report released Thursday the Air Force and prime contractor Boeing [BA], in the next 12 months, must complete software development and verify the software works as intended. Software problem reports are increasing and Boeing could have difficulty completing all testing if more retests are needed than expected, GAO said.

Boeing’s KC-46A (right). Air Force illustration.
Boeing’s KC-46A (right). Air Force illustration.

There were over 600 software problem reports as of January that needed to be addressed, GAO said, which will add pressure to an integration lab already operating at near capacity. Program officials told GAO that avionics flight management computer software has been a major contributor to the problem reports to date and that Boeing is working closely with this supplier to ensure problems are addressed. This particular supplier has also recently increased the number of staff working on this software effort from three to 24 people to address the backlog of problem reports.

Software development plans changed over the course of the past year, GAO said, in large part because the program solidified requirements at its critical design review (CDR). Boeing also brought two of the program’s software-intensive system components in-house and found ways to use some of its existing software. Boeing has increased its planned amount of reused software in its KC-46A composition since the program started in 2011, GAO said, which should ease implementation. Reused software accounted for 83 percent in its 2013 CDR, up from 76 percent in 2011. Boeing plans on using new software in only five percent of its composition.

GAO said the flight test program is also a concern because it depends on coordination among several separate government entities, requires timely access to receiver aircraft (the initial KC-46 will refuel while in flight) and requires a more aggressive pace than on past programs. The program office, GAO said, is working with Air Force officials to finalize agreements related to receiver aircraft availability to mitigate these risks.

Boeing spokesman Jerry Drelling said Thursday the GAO’s report recognizes the program continues to meet cost, schedule and performance estimates and has made good progress over the past year. This includes a successful CDR and ongoing production of four test aircraft and four booms that will support the flight test phase of the program this summer.

“Working closely with our Air Force customer, we remain confident in our plan to support Initial Operational Test & Evaluation (IOT&E) for the KC-46A,” Drelling said. “We continue to meet our contractual requirements (and) our most recent assessment of the schedule confirms that we have a valid flight test plan in place.  We remain on plan to deliver the initial 18 combat-ready Tankers to the Air Force by 2017.”