Unflappable

 作者:巨浓肺     |      日期:2019-03-07 09:01:01
By David Windle AIRCRAFT would be cheaper to make, easier to maintain and more reliable if they did not have moveable control surfaces such as flaps on the wings and elevators on the tailplane. So in a bold step, NASA and the US Air Force Research Laboratory are considering getting rid of them altogether. NASA and the USAFRL are undertaking a feasibility study into an aircraft called the Multi-Axis No-Tail Aircraft, or MANTA. It is also known as the X-44a. Part of the reason for the USAF’s interest is that such aircraft with no moveable control surfaces should be stealthier and more manoeuvrable. Instead of control surfaces, the plane’s direction will be controlled by precise movements of its jet engine nozzles, a system known as three-dimensional thrust vectoring. This will require a lot of computer power, but NASA is confident it is possible. A new fighter, the F-22, uses 2D thrust vectoring—and NASA has shown that an F-15 can use such technology to fly without using the aircraft’s moveable control surfaces. Steven Schmidt, NASA’s X-44a programme manager,