Scaled Composites has restarted flight testing of its Model 437 demonstrator, marking what the Mojave, California-based company said is the beginning of a new envelope-expansion campaign that will set the stage for joining Northrop Grumman’s upcoming Beacon autonomous flight program.
Scaled Composites confirmed that the Model 437 returned to the air in September 2025 after more than a year of modifications and ground evaluations since its first flight in 2024.
The upgrades made by the engineering team in Mojave were extensive: engineers overhauled the hydraulic system, integrated Beacon’s subsystems into the airframe, and developed new pilot interfaces inside the cockpit. Those updates, combined with ground tests jointly conducted with Northrop Grumman, laid the path for the resumption of flight testing that will now focus on demonstrating safe and reliable operation with advanced autonomy.
Beacon is Northrop Grumman’s newly unveiled open-access ecosystem for autonomous flight testing. Introduced in June 2025, the program is intended to accelerate the pace of software development by creating a shared environment where industry partners can evaluate and refine autonomy solutions together.
Northrop Grumman designed Beacon to allow multiple third-party participants to bring in their own mission software, integrate it with Northrup’s flight control systems, and quickly validate new capabilities. The Model 437, now modified for optionally piloted operations, serves as a primary testbed for these trials.
Tom Jones, Corporate Vice President and President of Aeronautics Systems at Northrop Grumman, described Beacon as “sixth-generation autonomous software development,” stressing that the program “bridges innovations across the industry while reducing both cost and time in delivering new autonomous mission solutions.”
Scaled Composites Project Engineer Yuto Shinagawa highlighted the unique obstacles of preparing the aircraft for Beacon.
“We had the challenge of taking an airplane that has only flown once and converting it into a versatile autonomous testbed,” he said, noting the team’s focus on flight safety and the integration of protections into the control system.
The Model 437 itself traces lineage to Scaled’s earlier Model 401 Sierra design. Powered by a Pratt & Whitney JT15D-5D turbofan producing around 3,400 pounds of thrust, the jet is capable of speeds of about Mach 0.85. Originally conceived as part of the US Air Force’s Loyal Wingman concept — now known as Collaborative Combat Aircraft — and evaluated as a potential escort for the UK’s F-35 fleet, it first flew in August 2024 form Palmdale, California.
After that first flight, the aircraft was withdrawn from service for modifications, reflecting its evolving role as a dedicated test vehicle for autonomy research. Its return to the air signals not only progress for Scaled and Northrop but also a broader shift toward accelerating autonomy integration in operational aircraft.
The revival of the Model 437 comes as the Pentagon advances multiple programs aimed at expanding flight autonomy. Initiatives such as the Air Force’s Collaborative Combat Aircraft effort and DARPA’s Air Combat Evolution (ACE) project have the goal of demonstrating how autonomous wingmen can complement manned fighters. By employing low-cost demonstrators like the Model 437, industry teams are able to explore integration issues and software performance in real flight conditions that cannot be fully replicated in simulators.
Beacon’s open-access model also offers potential benefits for government customers, providing a common environment where innovations from smaller firms can be tested and matured quickly. Northrop Grumman has emphasized that its approach lowers barriers for new entrants in the autonomy market while leveraging its decades of experience in operational flight control systems.
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