The US Air Force (USAF) has issued a request for proposal for the multi-billion dollar long-range strike bomber (LRS-B) programme.
The proposal has notified the requirements for the next-generation aircraft, but the details have not been revealed.
The LRS-B programme seeks development and delivery of up to 100 new, long-range stealth bombers at a unit cost of $550m.
US Air Force spokesman Ed Gulick said the request for proposal moves air force to the competitive phase of the programme.
The new bombers will replace the USAF’s aging B-52 Stratofortress and B-2 Spirit fleets.
US Air Force Secretary Deborah James said in a statement that the LRS-B is a top modernisation priority for USA, and will be an adaptable and highly capable system based upon mature technology.
"We look forward to industry’s best efforts in supporting this critical national security capability," James said.
B-2 manufacturer Northrop Grumman and a Lockheed Martin-Boeing team have revealed plans to bid for the contract, which is expected to be awarded in 2015.
The two bidders have not released any details of their platforms.
The air force has reportedly invested more than $500m in the programme since 2012.
Northrop Grumman spokesman Randy Belote told Bloomberg that the company’s design, production and sustainment of the B-2 bomber positions the company well for the contract.
Boeing-Lockheed team said in a statement: "We have the breadth and depth of proven technologies and talent, plus the infrastructure and scale that matches the importance of this mission."
The aircraft is expected to enter operational service with USAF in mid-2020s, DefenseNews reported.
Image: The new long-range strike-bomber will replace USAF’s ageing B-2 Spirit bomber. Photo: Public domain.