The sophisticated US stealth plane Model 401 with "odd markings" on its fuselage made another test flight earlier this week, Warzone editor Tylor Rogoway reports.
In an article published by the news outlet Verge on Thursday, Rogoway said that "the mystery" aircraft, developed by Northrop Grumman subsidiary Scaled Composites, flew over the Mojave Desert in the southwestern US and was escorted by an F-15D fighter jet.
The author specifically pointed to the experimental Model 401’s "new overall gray coating […] and large discolored diamond-like shapes below the cockpit and on its lower tail section".
"It is unclear what exactly these patches are for, but it seems like the Model 401s may be participating in a test that at least has something to do with their signatures, which can include radar, electronic, infrared, and visual", he noted.
According to Rogoway, the Model 401’s Mojave Desert flyover can be seen as sort of a coating test that was conducted amid efforts to reduce the plane’s infrared signature, which is "becoming more and more important as infrared search and track (IRST) systems are increasing in their capabilities and pose a real threat to stealthy aircraft".
The author also suggested that the latest Model 401 flight test was part of US efforts to "prove" the development of unmanned aerial vehicles, including Boeing’s "Loyal Wingman" combat drone.
"[…] It seems clear that whatever programme is underway involving these little stealthy jets it is a complex one that requires a large variety of assets and multiple test flights", Rogoway concluded.
Shortly after the Model 401 made its maiden flight in October 2017, Scaled Composites said in a press release the company had built two such planes in order "to demonstrate [their] advanced, low-cost manufacturing techniques and to provide aircraft for research flight services to industry partners and the United States government".