Northrop Grumman has pulled out of the competition to build the US Navy’s MQ-25A Stingray carrierbased tanker UAV, expected to be decided in 2018. The action came as a surprise as it had received US Navy risk reduction funding, along with its competitors Lockheed Martin, Boeing and General Atomics- Aeronautical Systems Inc (GA-ASI), and was expected to offer a design based on its X-47B that demonstrated the feasibility of carrier-based unmanned operations. An X-47B had already flown with a US Navy buddy tanking pod externally mounted.
A Northrop Grumman statement said only that, after the US Navy issued its request for proposals (RFP) on October 4, it did not believe it was “executable”. A draft RFP circulated to industry in July reportedly put more emphasis on potential intelligence, surveillance and reconnaissance (ISR) missions for the Stingray than did the final RFP.
While the contents of the RFP have not been publicly disclosed, Vice Admiral Michael Shoemaker, the US Navy’s ‘Air Boss’, has said two key performance parameters are the ability to give 15,000lb (6,803kg) of fuel when 500 nautical miles (926km) from a carrier and carrier operations suitability. Other, unconfirmed reports have stated the RFP stressed the tanker mission exclusively and did not consider secondary missions, such as the potential to serve as an ISR or communications relay platform. These were said to be areas where Northrop Grumman may have thought its design would have an advantage.
Little has been reported of the other Stingray competitors. Boeing is reportedly submitting a conventional design from the St Louis-based Phantom Works. The Lockheed design is reported to be a flying wing, emphasising stealth rather the fuel capacity. GA-ASI is said to be offering a carrier-based version of its MQ-1 Predator/MQ-9 Reaper. With Northrop Grumman’s withdrawal, the latter is viewed as the leading contender, although GA-ASI has no experience designing or building carrier aircraft or meeting US Navy requirements for shipboard use. The US Navy hopes to have the Stingray flying as soon as 2019-2020 with initial operational capability in the mid-2020s. David C Isby