The MQ-25A is intended to perform one of aviation’s most complex tasks, transferring fuel from one aircraft to another in flight. It is also designed to return and land on an aircraft carrier at sea without a pilot on board.
Boeing said the aircraft’s autonomy software is central to its operation. The software, described by the company as the aircraft’s “brains,” was designed, built and tested through years of verification before the Stingray left the ground.
The company said safety is the first consideration in designing any aircraft. It said operating without an onboard pilot creates distinct and new challenges that require a layered engineering approach.
Boeing said the MQ-25A uses thoroughly tested autonomy software and a contingency management system. These systems are designed to allow the aircraft to make safe decisions on its own in real time.
The aircraft is autonomous but keeps a human in the decision-making loop. Unlike some remotely piloted systems, the Air Vehicle Pilots operating from the ground or an aircraft carrier do not use a traditional stick and throttle.
Air Vehicle Pilots establish waypoints and flight paths for the MQ-25A. They then send commands such as taxi, takeoff and landing from the Unmanned Carrier Aviation Mission Control System, or UMCS.
The Stingray’s onboard autonomy translates those commands and manages onboard systems. These include propulsion, subsystems, guidance and flight control.
Boeing said its T1 test asset, which first flew in 2019, laid the groundwork for the Navy’s MQ-25A aircraft. The new MQ-25A Stingrays are designed for the conditions of aircraft carrier operations and are built for Navy deployments.
The aircraft also includes more advanced autonomy software and a contingency management system. Boeing said these systems build on lessons learned from the T1 test asset.
“The software flying on the airplane today isn’t just a first flight demonstration version,” said Mark Dunn, MQ-25 Mission Systems Integrated Product Team leader. “It’s significantly more complex and contains all the capabilities that let MQ-25A safely integrate seamlessly with the carrier air wing.”
Before the first flight, Boeing said its teams ran thousands of safety checks. The work focused on confirming that the software performed as intended and that the aircraft’s hardware operated reliably.
The software testing began three years before the first flight in a laboratory environment. Boeing engineers used the same Vehicle Management System Computers that would later be installed in the aircraft.
Engineers loaded the autonomy software and contingency management system onto those computers. They then tested the software independently to verify each decision and response.
After those checks, Boeing added real aircraft components to the lab setup. These included avionics parts and actual actuators from the aircraft’s hydraulic and electrical systems.
The company said this phase proved that the computers running the autonomy software could operate and control the aircraft’s systems correctly. After successful laboratory work, the same computers and software were installed on the aircraft.
Boeing and Navy teams then conducted extensive ground testing before the first flight. The company said the first flight aircraft completed more than 1,000 hours of ground tests.
Boeing said engineers also tested the autonomy software and contingency management system under a range of potential failure conditions. These included scenarios such as loss of GPS navigation, engine failure and loss of communication with the Air Vehicle Pilots.
“We had to consider all the possible scenarios the aircraft could experience in flight and ensure the airplane would autonomously react as we intended,” said Juan Cajigas, MQ-25 chief engineer.
In one test, Boeing repeatedly introduced a loss-of-communication condition. The contingency management system is designed to direct the Stingray to return autonomously to its departure airfield and land safely if communication with the Air Vehicle Pilots is lost.
Boeing said the MQ-25A includes 600,000 lines of safety-of-flight software code. The company also said the flight software underwent more than 200,000 hours of laboratory testing.
Boeing said the testing was intended to prove the aircraft’s autonomy, contingency systems and hardware before first flight. The company said the work prepares the MQ-25A for normal operations and operationally contested environments.
“One of the most critical elements of safety is partnering across teams to ensure our systems work as intended and can fly safely in all conditions,” Cajigas said. Boeing said the programme reflects a safety-first approach focused on precision, quality and sound decision-making.
