The US Navy is taking one of the final steps before sending out a request for proposals for its unmanned carrier-based tanker programme, with the release of a notice informing the industry that the competition for the MQ-25 development contract will be limited to four companies.

Naval Air Systems (NAVAIR) Command intends to issue the solicitation for engineering, manufacturing and development to Boeing, General Atomics Aeronautical Systems Inc., Lockheed Martin and Northrop Grumman, according to a 26 May notice posted on the Federal Business Opportunities website. NAVAIR also intends to release a solicitation to those companies for an accompanying contract for studies and analysis supporting the MQ-25 EMD programme.

Before limiting the competition to less than open bidding, the US military's acquisition procedures require NAVAIR must notify the industry in advance.

“These companies have refined their solutions and matured their technologies associated with the unmanned carrier-based aviation need and award to any contractor other than one of these four companies would result in significant schedule delays and require substantial duplication of costs which are not expected to be recouped by the government through full and open competition,” the notice states.

The concepts coming out of the EMD phase are expected to take a stark departure from the preliminary designs, which industry created to support the navy’s original requirement for a stealthy, carrier-launched surveillance and strike aircraft (UCLASS).

The navy has since changed course with the MQ-25 Stingray programme, focusing on a carrier-based airborne refueling system (CBARS). The UAV will not penetrate into defended airspace and attack targets, but the navy is planning a surveillance mission with a 19-23in-diameter forward looking infrared sensor turret.

In April, Lockheed Martin’s Skunk Works division offered a glimpse of their MQ-25 concept, though the image showed an wing aerial refueling pod trailed by a Boeing F/A-18 Super Hornet and did not illustrate a configuration.