G'day AM:
All that may be true. I'm pasting here an excerpt from Bill Werwage's Vulcan article that I think explains why the swept forward hinge line works so well. Billy is not an aeronautical engineer, and I'm certainly not either, so the more "learned" among us might not agree with his terminology, but it is an interesting piece, and it does make sense to me.
"The most significant thing that was different about the Vulcan was the high amount of forward sweep in the trailing edge. This was done with two thoughts in mind. I wanted to keep the center of pressure (CP) from moving aft on the wing when the flaps were deployed. With the forward swept hinge line, the average flap position is ahead of the point where it would be on a straight hinge line model, and therefore when deployed the flaps would not move the CP as far aft. The effect this has is to not over stabilize the model by moving the CP too far back from the center of gravity. In other words the model would not become as nose heavy with the flaps deployed. One of the major benefits of this arrangement is that the stick pressure felt in the handle, especially in high wind conditions, is dramatically reduced. Remember, that when the flaps are moved either up or down, the airfoil is changed to an undercamber type, which increases the wing’s lift. But it also changes the point of the center of the lift, which is also known as the center of pressure.
“On a straight trailing edge model, when the flaps are deployed, the CP moves a much greater distance, and over stabilization occurs. The results are more stick pressure, and a model that requires more input to achieve directional change. In calm conditions this is almost imperceivable, but in heavy wind it can be dramatic!
“Another benefit of the forward sweep in the trailing edge hinge line is the effectively longer tail moment. The moment is now measured from the average of the flap’s position in relation to the stabilizer/elevator hinge line.”
Okay, whatever the reason, the swept forward hinge line suits me. The back problems I'm having might preclude me from producing many - if any - more of these things, but the swept forward TE will always be incorporated. I have reduced the amount of sweep lately, but it is still there in my new twins, and the new (last...) Genesis has the increased amount as did the 1980 Genesis and the Crossfire.
Later - Bob