A recent post in another thread noted that on old Nieuport monoplanes there were only a handful of compression ribs and the rest of the wing profile was defined by strips of wood bent around the spars after the fact. A number of ultralight aircraft also used sailing-style sewn pockets with wood, aluminum or fiberglass battens to define at least part of the wing profile. This seems like an interesting method to avoid making lots of jigs for different ribs at every station for simple, slow, lightweight aircraft that use tapered wings, for example, in creating a swept and tapered wing with washout for a tailless design. Presumably, this would work best with a semi-symmetrical airfoil like the NACA 23XXX series or something similar.
I could see using a leading edge tube, tube-capped truss spars forward and rear (or joined as a box spar), and a bent sheet metal trailing edge to define the key points on the contour. They would be held in place temporarily by simple plywood root and tip jigs. Cheating the leading edge tube a little high at the root and a little low at the tip, doing opposite at the trailing edge, and a matching slight offset to the front and rear spars would give gradual washout from root to tip. Then fiberglass or aluminum battens, or maybe laminated wood strips, could be attached with rivets, screws or even lashed with epoxied tape or twine to define the wings contours. If needed, additional truss or gusset bracing could be added to the ribs after the top and bottom strips are in place. Ailerons or flaps could be hinged from the rear spar or false spars if desired and cut out from the wing. Cover the wing with fabric by your chosen method and there you go.
I am sure this has been done before. Examples, pros, cons?
Cheers,
Matthew
I could see using a leading edge tube, tube-capped truss spars forward and rear (or joined as a box spar), and a bent sheet metal trailing edge to define the key points on the contour. They would be held in place temporarily by simple plywood root and tip jigs. Cheating the leading edge tube a little high at the root and a little low at the tip, doing opposite at the trailing edge, and a matching slight offset to the front and rear spars would give gradual washout from root to tip. Then fiberglass or aluminum battens, or maybe laminated wood strips, could be attached with rivets, screws or even lashed with epoxied tape or twine to define the wings contours. If needed, additional truss or gusset bracing could be added to the ribs after the top and bottom strips are in place. Ailerons or flaps could be hinged from the rear spar or false spars if desired and cut out from the wing. Cover the wing with fabric by your chosen method and there you go.
I am sure this has been done before. Examples, pros, cons?
Cheers,
Matthew
