Boeing has joined a team of suppliers supporting General Atomics Aeronautical Systems’ bid to win the US Navy’s MQ-25 Stingray programme even as it continues to promote a clean-sheet alternative design.

Boeing’s Autonomous Systems division will support GA-ASI’s bid for the carrier-based, unmanned tanker “with our aviation and autonomous experience”, says Chris Raymond, vice-president and general manager for the division.

The announcement comes less than two months after Boeing’s Phantom Works unit revealed with great fanfare a fully assembled MQ-25 ground test vehicle in St. Louis. Boeing’s presence on GA-ASI’s list of suppliers for a rival design doesn’t change the company’s plans to offer its own aircraft for the Navy contract.

“Pursuing the programme as a prime bidder and a member of the General Atomics team is good for our customer and reflects our focus on doing what’s necessary to compete, win and grow,” Boeing says.

GA-ASI’s announcement also clarifies other details of the company’s bid as Naval Air Systems Command evaluates proposals for the MQ-25, which also include a separate offer from Lockheed Martin.

If selected, the GA-ASI Stingray would be powered by the nearly 16,000lb-thrust Pratt & Whitney Canada PW815 turbofan engine. GA-ASI is so far the only bidder in the MQ-25 competition to have revealed an engine choice. It shows that the MQ-25 will be considerably larger than GA-ASI’s jet-powered Predator C Avenger unmanned air system, which is powered by the nearly 4,000lb-thrust PW545B turbofan.

GA-ASI also selected UTC Aerospace Systems to design and build the landing gear and GKN Aerospace’s Fokker business to supply the arresting hook.