The blown wing concept

The main challenge in thinking about a blown wing is to remember that when you blow the wing, you are decoupling the airspeed over the wing from the airspeed of the plane as a whole.

Ok, what the heck does that mean? Imagine a plane sitting on the runway, brakes locked, no wind. The airspeed of the plane is zero. The airspeed of the air flowing over the wings is also, of course, zero.

Now imagine that same scenario, but with a blown wing like ours—one where there are numerous props along the leading edge. Again, no wind and brakes locked. The airspeed for the airplane is zero. But the airspeed over the wing is (let’s say) 70 knots. So we see that a blown wing decouples the airspeed of the plane from the airspeed over the wing.

Ok, great, what does that do for us? In most airplanes the wing is designed such that it does its job over a range of airspeeds—slow for takeoff and landing and faster for cruise flight. This means that the wing can never be fully optimized for one specific task, unless you are designing a plane that takes off, lands, and cruises all in a very narrow range of speeds.

A blown wing can be optimized for cruise flight because we are actively pushing air over the wing at a different speed than the plane itself is actually going. So on landing the plane may be going 50 knots, but the air over the wings is going 80 knots.

What you can then do is use a much smaller wing for the same job. For an airplane of equal weight and cruise speed, it is possible to use a blown wing that is fully 70% smaller than a traditional wing would be. This directly leads to a very large reduction in drag.

We aren’t aiming for that 70% reduction right out of the gate; we are building a wing that is around 50% smaller than would normally be used in a plane our size.