Bell presented the details of the project as part of the Darpa Sprint program, the purpose of which is to create a hybrid aircraft that combines the possibilities of a helicopter and a reactive aircraft. The experimental X-Plane is not only able to fly up and sit down vertically, but also overcome long distances at high speed, which makes it a universal solution to fulfill missions in difficult conditions.
The idea to combine the advantages of helicopters and jet jets appeared thanks to the Sprint program. For decades, it has been believed that vertical take-off and high speed are mutually exclusive features. However, the new DARPA development allows you to create an apparatus capable of moving from freezing and maneuvering on the spot to a flight at a speed of more than 800 km/h.
The design of the aircraft resembles the Bell Boeing Osprey, but with a number of unique features. After a vertical take-off, he puts his rotors into a horizontal position, and then folds the blades into special fairings to eliminate air resistance. At the same time, the flight control is completely transmitted to reactive engines, which provides incredible speed and range.
The first tests of Stop/Fold, developed by Bell, were held in 2023 on the US Air Force test route in New Mexico. The prototype of the folding mechanism of the blades was tested under conditions that simulate real flights. The next stage was the aerodynamic tests of the X-Plane model at the National Institute of Aviation Research in Kansas. It was there that the engineers demonstrated the physical model of the aircraft, only in the form of concept arts.
The new model is distinguished by the streamlined case, thin wings and V-shaped tail. Folding rotors integrated into the back of the fairings allow the device to quickly adapt to various flight conditions. According to Bell, a manned or autonomous version of the aircraft will be able to develop speed up to 518 miles per hour (833 km/h) at an altitude of up to 9,100 meters, overcome up to 370 km without refueling and transport goods up to 2,300 kg, including small equipment.
The development is designed to perform missions in difficult and potentially dangerous conditions, including operations in the Indo-Pacific region. Increased range, high speed and ability to quickly adapt, provide a significant advantage for special units in conflict zones.
“After successful testing of the Stop/Fold system based on the Air Force last year, we are pleased to report the successful completion of aerodynamic tests. This is an important step in the development of new generation aircraft,” stated Executive Vice-President of Engineering Development Jason Hurst.
Bell is sure: