I’m curious where this fits relative to the technique of adding little vortex generator fins along the top of the wing. Is this part of that same effect? Or something completely different. The article talked a lot about their testing and results, but was light (imo) on the why.

So you're telling me if United goes out and gets a bunch of paper bags to attach to the wings it will reduce drag by 30%? Are there industrial materials that can do this on a 747 and sustain hundreds of hours of flight? I have so many questions. Exciting to see.

My gut reaction was of course “oh but more drag” since the general rule to adding surfaces to aircraft increases drag. But they claim a reduction of 30%.

This all seems pretty novel. I’m curious what went wrong previously? Why don’t we do this now?