B-21 Avionics Testbed Aircraft Now Operating, USAF Official Says

B-21 concept
Credit: U.S. Air Force

The U.S. Air Force has commissioned a flying testbed aircraft to test the avionics system and software for the Northrop Grumman B-21 bomber, a senior official said on Aug. 13. 

The first B-21 test aircraft is still being assembled in Palmdale, California, but the flying testbed allows the stealth bomber program to “buydown risk,” said Randall Walden, director of the Air Force’s Rapid Capabilities Office, which is managing the program. 

“We have a flight test aircraft that we’ve been hosting some of these subsystems on,” Walden said. “We’re doing it kind of in a parallel approach, working out some of the bugs with the software as well as the subsystems.”

Walden, speaking to the Air Force Association’s Mitchell Institute, did not identify the flying testbed, but his remarks come two months after the appearance of a green Boeing 737 owned by the Air Force with registration N712JM.

The Lockheed Martin F-35 program also used a 737 to check out avionics and mission systems before test flights of the stealth fighter started in 2006. 

“When you can buydown risk with subsystems on even another platform, no matter what it is like you get into the air and use some of the software and work those bugs out it goes a long way,” Walden said. 

The Air Force expects to field the B-21 in the mid-2020s, about a decade after awarding the engineering and manufacturing development contract to Northrop in 2015. 

The development program remains on track, but Walden is eager to begin testing as soon as possible. 

“All of the tough critical designs, all of the hard engineering, is behind us,” Walden said. “I know we’re not going to be immune from design flaws. We’re going to have to work through those, and we’re doing some of that today. I want to find out what those design deficiencies are as fast as I can to get on with the solution.”

Steve Trimble

Steve covers military aviation, missiles and space for the Aviation Week Network, based in Washington DC.