U.S. and Israel compete in designing VTOL aircraft

Aircraft designers all over the world continue to invent the aircraft that would take off vertically and remain a fast-flying vehicle, rather than a slow-speed helicopter. High speed, efficiency and elegant design is what creators of a completely new aircraft need.

The versatility of helicopters and other aircraft of vertical take-off and landing (VTOL) makes them ideal for use under military conditions. But all helicopter advantages immediately disappear when, having hovered in the air for a little while, it proceeds to a horizontal flight. Currently, only helicopters can maneuver in tight airspace. Only helicopters can land on the ground in unprepared areas, move in all directions, and hang motionless in the air, carrying out surveillance.

However, compared with airplanes, helicopters are much slower, which makes them vulnerable to any weapon. Special operations of speedy attacks require appropriate rapid response from health departments, in particular when it comes to evacuation of wounded people. To do that, one has to increase the flight speed considerably.

For example, in the vertical take off model of the modification of U.S. fighter F-35 Lightning 2, the vertical launch fan, coupled with the jet engine, weighs more than two tons - more than the jet engine. The fan works only during takeoff and turns into useless "dead weight" in level flight. 

"To overcome this problem, DARPA launched VTOL X-Plane program to challenge traditional aviation technologies and at the same time go beyond certain limits in four areas: speed, performance management, effective range and payload," program manager Ashish Bagai told reporters. However, this is very hard work that designers have to pursue. After all, they need to create an entirely new aircraft that combines the advantages of an airplane and a helicopter and at the same time remains deprived of their shortcomings.

Meanwhile, Israeli company Urban Aeronautics also develops a project of high-speed UAV VTOL based on AirMule, reports Flightglobal, the website of Flight International magazine. The company has achieved impressive progress. The work began in 2009, when the first tests of the unmanned vehicle were made in a wind tunnel. The tests showed that the design that engineers selected worked pretty well!

As expected, a model of a new cargo UAV, capable of high speed, will have a 1,600-horse-power engine. It will be 20 percent larger and 50 percent heavier than the AirMule. According to preliminary calculations, this vehicle can be used by the military as a safe aircraft for rapid deliveries of ammunition and food in war situations.

The design of the aircraft is unusual but apparently, this is what made it successful. It has two fans - one on the front and the other one - on rear part. To fly horizontally, the drone would just lean forward or backward. The fans will also make the aircraft move in the required direction.

The Israelis designed quite an impressive aircraft. Its takeoff weight makes up 1.4 tons. It is capable of carrying up to 635 kilograms of weight. It can reach the speed of up to 180 km/h, fly at altitudes of up to 3.7 thousand meters and stay in the air for up to five hours. In the future, the new UAV will be used to deliver ammunition, food and to evacuate the wounded from the battlefield. It is reported that the Israeli Defense Ministry has shown interest in the aircraft.

Vyacheslav Shpakovsky

Pravda.Ru

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