BAE envisions spinning fixed-wing drones

BAE envisions spinning fixed-w...
An Adaptive UAV, transitioning between fixed-wing and rotary wing modes
An Adaptive UAV, transitioning between fixed-wing and rotary wing modes
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An Adaptive UAV, transitioning between fixed-wing and rotary wing modes
An Adaptive UAV, transitioning between fixed-wing and rotary wing modes

There are already a number of drones that take off and land vertically, but switch to faster, more efficient fixed-wing flight once airborne. Working with students from Britain's Cranfield University, BAE Systems engineers have taken that idea and put a whole new spin on it – quite literally.

The BAE/Cranfield team has created a concept for what it calls Adaptable UAVs (unmanned aerial vehicles).

Envisioned for use by armed forces within the next few decades, the aircraft would fly with both of their motor/propeller units facing forward when in fixed-wing mode. For take-offs and landings, however, one of those units would rotate around to face backward. This would cause the UAV to convert to rotary wing mode, in which the whole aircraft would spin around on the spot, rising or falling vertically.

As can be seen in the rendering at the top of the page, the drones would also have a large hole in the middle. This would be used in take-offs and landings, as whole swarms of the aircraft would be stacked on mast-like poles, which would run through the middle of them. Those poles would in turn be gyroscopically stabilized, so they would remain stable and upright even when mounted on ships in rough seas, or on moving land vehicles.

For more information on how the technology would work, just watch the video below. And for another example of a collaboration between BAE and Cranfield, check out the fixed-wing DEMON UAV, which maneuvers using nothing but a series of forced-air jets along the trailing edges of its wings.

Source: BAE Systems

BAE Systems future technologies: unmanned air vehicles may use fixed and rotary wing flight

I need a little more explanation why spinning one fixed wing backwards works unless it also rotates to provide lift while moving in the opposite direction to the other wing. Even then this would seem hard to balance the lift on both sides and provide stability.
@ Bob - To me it looks like they're just throwing ideas at the wall to see what sticks.
It's pretty much what happens every time a new and exciting technology comes up, isn't it?
Stephen Colbourne
Rather than twisting one motor round relative to the wing , it would be much easier to just run the motor backwards.
I think even spinning the craft round is a bit too complex. If the motors are powerful enough, it should be able to land and takeoff, by pivoting the wing 90 degrees and landing with the motors facing upwards. Spinning the wing could be more efficient with limited power, I accept.
Ralf Biernacki
@Bob and Stephen: you are missing the point. They are not just rotating the motor around a fixed wing. What they propose is twisting the entire wing, including its fixed motor nacelle, around its long axis by a little less* than 180°. This will work in the "helicopter" configuration, provided that they use a symmetrical (top-bottom, not front-back**) airfoil. Such airfoils are commonly used in acrobatic airplanes, and they are only slightly less efficient than cambered ones.

*180° minus twice the angle of attack, to be exact.

**An airfoil symmetrical front-to-back would work poorly, just as Bob suspected.

The video only shows rotating the motor backwards, not the wing.
Ralf Biernacki
@Bob: You're right, that's what the video shows---but it makes no sense. At the very least, the angle of attack of one wing must change, otherwise it will develop negative lift going backward. And any imbalance of lift between the two wings will immediately tumble the drone. It hardly even has control surfaces.