GA-ASI Maximizes Fuel Capacity for MQ-25 Entry

The integrated fuel tank structure improves fuel carriage and delivery capacity for General Atomics’ entry in the MQ-25 competition

July 10, 2018

William Kucinski

GA-ASI’s MQ-25 design, pictured here refueling a Lockheed Martin F-35 Lightning II aircraft, is based on an enlarged version of their Predator C Avenger long-endurance, medium-to-high-altitude remotely piloted aircraft (RPA) system (Image source: GA-ASI).

General Atomics Aeronautical Systems, Inc. (GA-ASI) of Poway, Calif. is using an integrated fuel tank structure to maximize fuel offload for the company’s proposed MQ-25 design for the U.S. Navy.

GA-ASI’s MQ-25 design features a conventional wing-body-tail design (Image source: GA-ASI).

The MQ-25 “Stingray” unmanned, carrier-based, aerial refueling aircraft is an unmanned combat aerial system (UCAV) that the Navy plans to field by the early- to mid-2020s. While the MQ-25 will mainly serve as an aerial refueling platform for Navy aircraft, it is likely that the chosen entry will also possess limited intelligence, surveillance, and reconnaissance (ISR) capabilities.

In October 2017, the Navy released the final request for proposals for the MQ-25. At the time, the main competitors were Boeing , General Atomics, Lockheed Martin , and Northrop Grumman ; although, Northrop Grumman withdrew from the competition at the end of October 2017.

GA-ASI’s MQ-25 design – dubbed the Sea Avenger – is based on an enlarged version of their Predator C Avenger long-endurance, medium-to-high-altitude remotely piloted aircraft (RPA) system.

GA-ASI applied its knowledge of advanced composite aircraft structures to develop integrated fuel tanks in a large-scale wing box test article and a full-scale wing skin pre-production validation article.

Boeing's proposed MQ-25 design is based on the company's Boeing Phantom Ray flying-wing prototype. Boeing has been developing carrier aircraft for the U.S. Navy for more than 90 years (Image source: Boeing).

The wing box tested to failure via wing bending at GA-ASI’s Adelanto, Calif. structural test facility last year. In April, the company verified the production readiness of the co-cured wing and tail components using both non-destructive and destructive inspections.

“The integral fuel tank wing box test article will reduce technical and schedule risk for the program,” said David R. Alexander, president of aircraft systems at GA-ASI. “Specifically, through extensive validation of fuel containment sealing methods, advanced non-linear buckling finite element analysis models and thick composite laminate construction, we have accelerated engineering design consideration prior to the detail design phase and production.”

A full-scale inner-wing skin demonstration article built in March at GA-ASI’s Spanish Fork, Utah facility verified the MQ-25 tooling concepts, lamination approach, and processes. The team validated the outer mold line tooling approach for the build process which enables accelerated engineering and tooling fabrication for the MQ-25 program.

Lockheed Martin's RQ-170 Sentinel-based MQ-25 prototype features a flying-wing design, much like Boeing's entry. Lockheed Martin asserts that the flying-wing design is 20% lighter, 25% more aerodynamically efficient, and 10% smaller in regards to taking up carrier deck space (Image source: Lockheed Martin).

GA-ASI’s Predator C-based wing-body-tail design will compete against two flying wing designs: Lockheed Martin’s RQ-170 Sentinel-based prototype and an iteration of the Boeing Phantom Ray .

William Kucinski is content editor at SAE International, Aerospace Products Group in Warrendale, Pa. Previously, he worked as a writer at the NASA Safety Center in Cleveland, Ohio and was responsible for writing the agency’s System Failure Case Studies. His interests include literally anything that has to do with space, past and present military aircraft, and propulsion technology.

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