Almost two-and-a-half years after it first flew, and two years after the program was abandoned, Scaled Composites has quietly revealed more details of its Model 400 Swift proof-of-concept aircraft. The Model 400 was built as part of Northrop Grumman’s response to the USAF’s T-X advanced jet trainer requirement, but was abandoned in February 2017 when the company (and its principal teammate BAE Systems) decided not to submit a proposal for the T-X trainer program, which it judged “would not be in the best interests of the companies and their shareholders.”

Northrop Grumman was initially teamed with BAE Systems and L-3 Communications for the T-X program and originally offered the Hawk Advanced Jet Trainer (AJT) as its T-X platform. A decision was subsequently made to incorporate a new air vehicle into the team’s T-X solution when timescales moved to the right, and when it became clear that the Hawk was no longer the optimum solution “in terms of requirements and affordability.”

BAE Systems remained part of the team thanks to its experience and capabilities in embedded air vehicle training capability, but Northrop Grumman turned to its Scaled Composites subsidiary to design and build a new trainer platform. Northrop Grumman subsequently said that it had “used advanced design and prototyping techniques to build a purpose-built aircraft for the competition. The aircraft combines Northrop Grumman and Scaled Composites’ innovative approach to aircraft design, development, and rapid prototyping.”

Throughout the brief life of the Model 400, Northrop Grumman and Scaled Composites (a Northrop subsidiary since 2007) issued no detailed press releases or photos relating to the aircraft, announcing only that the Model 400 prototype would be officially unveiled in early 2017. The prototype was seen and photographed during taxi trials at the Mojave Air and Space Port on August 19, 2016, revealing its FAA registration number, N400NT. This then revealed the aircraft’s Model 400 designation, its F404-GE-102D powerplant and showed that Scaled Composites had registered the aircraft on June 16, 2015.

We now know that the aircraft made the first of its seven flights one week later, on August 26, 2016, having gone from concept to first flight in only two years. Scaled Composites described the aircraft, now revealed to have been named the Swift, as “a low-cost, high-performance, proof-of-concept jet designed to meet high-G, high angle-of-attack maneuvers.”

This gave Scaled Composites the challenge of “a new loads environment,” requiring the company to test the aircraft's wing structure design “for a significantly higher-G environment than we usually design to.” Newly unveiled photos of the prototype in build show that all-composite wing to be an innovative one-piece, three-spar structure.

With a quoted maximum takeoff weight of 15,400 pounds, the Model 400 was lighter than the winning Boeing/Saab design and lighter than the M-346-based Leonardo T-100 or the Lockheed/KAI T-50A. Surprisingly, Scaled Composites gave a maximum speed of just 500 knots for the aircraft (325 kts was achieved during the test programme), and a maximum altitude of just 35,000 feet.

In January 2017, shortly before Northrop Grumman announced its intention not to bid, CEO Wes Bush said that the company was looking at T-X “through the cold, hard lens of what does the RFP really tell you, and what would the business case look like?” He warned: “We don’t want to walk ourselves into a decision to do something just because we’ve been doing it.”