Drones have a fundamental design problem. The type of drone that can carry large payloads at high speed over long distances is fundamentally different from the type of drone that can take off and land from a small area. In very simple terms, for the first, you want fixed wings, and for the last, you want rotors.

This problem has resulted in a series of strange UAVs that attempt to do both of these things at once, usually by combining the desired characteristics of fixed-wing UAVs and rotorcraft. We saw tail guard drones that can go from vertical takeoff to horizontal flight; we have seen drones with rotating propeller systems; and we have seen a whole series of aircraft that are essentially quadrimotors stapled on fixed-wing aircraft to give them vertical take-off and landing capability. These types of tradeoffs work, more or less, but they inevitably add weight, cost, and complexity to do whatever they need.

A South African company called Passerine has a better idea, which is to do what birds do: use wings to fly effectively by leaning on the legs and feet for take-off and landing.

This is a rendering of Passerine's drone, called Sparrow. The first thing to note is, of course, these legs, in which we will definitely enter. But the design of the fixed wing cell could be a better place to start. These wing engines create what is known as a blown wing, where the engine exhaust passes over the wing and over part of the flaps. The high-speed forced air that passes over the wings and flaps generates great lift (two to three times the lift of a conventional wing) and, since the air comes directly from the engines, you benefit from this lift even if does not move much. This contrasts with most conventional wings and flaps, whose performance depends on the speed of the aircraft. The result is that aircraft with blown wings or flaps can take off and land a much shorter distance and fly much more slowly before landing.

To be clear, the blown wings are not the idea of ​​Passerine, and they have existed for a while. Antonov, from Ukraine, is currently producing a cargo aircraft with a similar engine, and NASA tested this short-range silent search aircraft (QSRA) in the 1970s, showing that it could take off and land on an aircraft carrier without catapult or stop device, with room to spare.

Hey, people hope you like this article, please share this article with your friend and family. Also comment on your views and thank you for reading this article.