vasek,

mogman is correct. They are simple tubes to vent the fuel tanks mounted in the wing center section. I have seen them in this shape (sort of a ?) and in a inverted L shape. They are usually hand formed so that they vary from plane to plane and I haven't seen any pairs that match. The Newer YMFs with optional auxillary wing tanks will have a vent tube on the inboard end of the tank (airliners has pictures of four tank setups). NC 14081 only has the center wing tanks and has the vents mounted next to the fuel caps (which are a different style than the one above) instead of behind.