With over 150 views this puppy stopped hunting, so here are the answers. Beginning in 1953 Willard Custer, an American aviation engineer experimented with his "channel wing" design for accelerated wing lift at low twin engine aircraft speeds
1.2. With 12 years of experiments with what he called the "channel wing", his inner panels of each low wing have a "U" shape with two strut-mounted engines turning pusher props are strut-mounted, one engine on each wing. The props draw air through the channel on each wing. This decreases pressure over the wing; increasing lift. Testing revealed lift off at aircraft speeds as low as 35 mph and takeoff after only a 50 foot run. The wings also housed retractable landing gear and had an external brace between the lower two channels..