In my experience, the 'no engine' thing is a deterrent. That's why I
stress that we do have one, - gravity.


I agree 100%. The "no engine" thing is for the teeny boppers who "need" a
thrill. For the nervous prospect, I tell him that an aircraft flies on its
wings, not on an engine. And if he seems somewhat intelligent (you'd be
amazed!) I try to discuss a bit of the physics (gravity, vectors, etc.).