The military gliders made sense because they were landing in hostile territory, usually nowhere near a runway for a return trip. Those gliders were pretty much a one-way, one-time-use vehicle. I guess the Waco glider could be used to argue that towing is technically feasible, but it was intended for a totally different use case. I don't see how it can be argued that it's more economical to run, especially considering the safety issues others have pointed out.

I'm no aerospace engineer but it seems like it would be more efficient to fly one single bigger plane than to tow a second one behind it. I suppose this might appeal to certain groups where they already own a plane, and want to increase capacity without buying a whole new plane. But the idea that it's 65% more efficient just seems pretty sketch. I could totally imagine some drug cartels using these though...

If you've got a bigger plane, you also need a bigger runway. This thing should increase the number of usable airfields. That could be interesting for avoiding more expensive routes.

If your plane+cargo glider weight is the same as your larger cargo plane weight, won't you need the same amount of runway?

Your towing plane is going to have to accelerate the same mass to takeoff speed before it can get off the ground, no?

It is, but that only happens at one end of the trip. It can still drop cargo on a smaller airfield at the other because the braking can be done independently by both.

Plus there's an interesting wrinkle here: a lot of the media on the site show the tow plane as one with engines, and not a glider. I'm sure that's because those are the aircraft they could get their hands on, so that's what they made it work with, but the option is there to have the towed plane powered on takeoff. Doing that safely, with the two aircraft tethered... that sounds like a mess. But it's an option!

> but that only happens at one end of the trip

Ah, I get what you mean.