Development and delivery of the US Air Force’s B-21 stealth bomber could stall if Congress passes yet another short term funding bill that would freeze the Pentagon’s spending limit at previous fiscal year levels, a senior USAF official warns.

In a speech this week on Capitol Hill, USAF undersecretary Matt Donovan cautioned against another interim funding measure called a continuing resolution, which would hold funding of the Northrop Grumman programme at fiscal year 2017 levels. That would limit the air force’s ability to execute the programme’s engineering, manufacturing and development phase, he says.

The continuing resolution impacts several other new start programmes within the air force, including an effort to produce four new wing sets for the service’s Fairchild Republic A-10 fleet.

The USAF requested $1.3 billion in its FY2017 budget for the B-21’s engineering, development and manufacturing phase, which the service ramped up to $2 billion in its FY2018 request. Under a continuing resolution, the B-21 programme would see a $700 million shortfall for the development phase.

The air force has already been operating under a continuing resolution for the past four months, though the constraints have not yet affected B-21 development, Donovan says.

“We specifically have checked with the folks to see at what point and they had told us that once you get to about six months, then it’s going to start affecting,” he says, adding the programme will slow down at that point.

Donovan would not elaborate on how much the continuing resolution would delay the B-21 delivery or impact its expected initial operational capability milestone in the mid 2020s. He also suggested the USAF would not seek an anomaly status for the B-21 that would exempt the programme from budget freezes during a continuing resolution.

“If we’re not able to ramp up on our schedule for the acquisition program baseline, then of course it’s going to have an impact on the other end,” he says. “You can’t make up that time.”