SEATTLE – Boeing [BA] has finished 95 percent of the testing it must conduct with its new KC-46A Pegasus tanker before it can start delivering the refueling jet to the U.S. Air Force, according to company officials.

In those tests, the program has amassed almost 3,000 flight hours, completed more than 1,600 contacts during refueling flights and transferred almost 2 million pounds of fuel. 

A KC-46A test plane at Boeing Field in Seattle. (Photo by Marc Selinger/Defense Daily)
A KC-46A test plane at Boeing Field in Seattle awaits its next flight. (Photo by Marc Selinger/Defense Daily)

The remaining 5 percent, which Boeing expects to wrap up in the coming months, will try out a software enhancement to the remote visual system (RVS). It will also lead to the certification of initial fuel-receiver aircraft, company program officials told reporters during a tour of Boeing’s Seattle-area tanker facilities May 3.

“Overall, we’ve come a long way,” said Jeanette Croppi, Boeing’s KC-46 test program manager. “We have a little bit more to go.”

Provided by Rockwell Collins [COL], the RVS is a camera system that allows the operator to determine if the refueling boom or centerline drogue system (CDS) is working properly. The enhancement, which began flight tests in mid-March, is designed to improve the visibility that the RVS provides when the sun causes glares or shadows.

The enhancement is also expected to help reduce boom scrapings, or unintended contact with receiver aircraft outside the refueling receptacle, said Mike Gibbons, Boeing’s KC-46 vice president and program manager. The rate of such contact is already “very low” and comparable to that of legacy tankers, Gibbons said.

The receiver certification testing will involve the C-17 transport plane, F-16 fighter and KC-135 tanker. F-16 testing is 40 percent completed, and KC-135 testing was slated to begin May 3. The certification tests will build on refueling that the KC-46A conducted earlier with the three receiver planes.

Boeing is also trying to resolve a problem with the CDS. Gibbons said the company has devised a “simple” software fix to prevent the CDS from committing un-commanded disconnects from receiver aircraft.

“It’s a tuning issue,” he said.

Boeing plans to install the CDS software fix this summer and then flight-test it. That effort is not expected to affect the timing of aircraft deliveries.

Exactly when aircraft deliveries will begin is the subject of debate among Boeing, the Air Force and the Government Accountability Office (GAO). Leanne Caret, chief executive officer of Boeing Defense, Space & Security, told reporters that Boeing expects to deliver the first 18 aircraft by year’s end. But according to a recent report by the GAO, that milestone might not be achieved until May 2019.

Boeing, which has been developing the KC-46A since 2011, was originally supposed to deliver the first 18 planes by August 2017. But delays in completing flight tests and obtaining airworthiness certifications prevented that target from being met. Production has continued, with dozens of KC-46As in various stages of assembly.