Post by David E. Powell
I was just thinking, a few years ago, I saw a concept for a modern "Biplane" type arrangement for a twin jet passenger or cargo jet. The bottom airfoil pinched up, and I was thinking of the old Bellanca Aircruiser, and the unique wing arrangement that the Aircruiser had going on.
So, here's my take on the "Flying W" wing concept in the Jet Age: How about doing it with an "almost straight" wing, just as much sweep as you need for the speed you want, maybe even a "cranked" wing with a straighter inner section (The trailing edge straighter than the leading edge) with the two turbofans positioned to direct thrust into that center "gap" in each side's wings. This could be worked into almost a "channel wing" arrangement, with the thrust worked to provide a bit of additional lift.
This arrangement could lead to some great benefits for a short field operation profile, and while not a true "channel wing," could be a neat hybrid for the purposes of getting a bit of benefit from that lift while maintaining a more traditional layout and handling characteristics at higher speeds.
Of course, the arrangement could make for a convenient landing gear location, retracting into the lower "W Wing" points on each side, with a nose gear up front. (The trick would be designing the nose gear, I think!)
This is all very well if you are happy to cruise around at a low speed
but there have been some considerable advances in aerodynamics since
The sort of aircraft you are talking about to fill that niche that were
produced in the post war period were
The Short 330 & 360
CASA C-212 Aviocar
DHC-6 Twin Otter
These are almost all high wing turboprop aircraft which get extra lift
at low speed by having the air blown over the wing surface and flaps.
The construction is simple, maximises payload space, makes for ease of
loading and it works.
If you want the grand parents of this type see the Fairchild C-119
Flying Boxcar and Bristol Type 170 which operated as an airborne car
ferry across the English Channel in the 1950's and 1960's