On 07/01/2013 07:49 PM, Sidsel & Svein Johnsen wrote:
> Do this, Frans: Shake off all your conceptions. Look ONLY at my
> illustrations. The global airplane forces are actually this simple.
I think we are both right, but each of us looking at a different
situation. You are talking about the airplane as a whole.
But for me, as this was the topic of the original discussion, the
question is: what kind of forces do the wings pose on the fuselage?
As the fuselage doesn't want to go forward without the wings, but still
goes forward with the wings, it looks to me that it is possible that the
wings somehow pull the fuselage forward.
And of course I have some clues as why the airplane (as a whole)
actually flies and I agree with your drawings, but again, the topic was:
the rear wing sockets, do they push or do they pull?
To really answer this question you should drawn the vector diagrams not
for the airplane as a whole, but for each of the components that make up
the airplane. And then it would be interesting to see what resultant
force is acting on the rear wing sockets.
Mind you, I might be totally wrong on my idea. But I have a feeling that
it is beyond just our reasoning to really have a grasp which forces are
acting where on the individual interconnecting components. As I recall,
the "cuff" around the two wingspars was a "fix" for some unforeseen
force acting on the wing spars causing them to twist somehow around each
other. Despite the great souls working on the original design of the
wings, it was not foreseen that the cuffs would be necessary.
Has anyone actually ever tried to fly without the rear pip pins in? If
so, what happened? If not, what would happen? Could you get away with
it, or will the wings fold forward during the landing flare?
I don't think the forces are too large anyway, as the original Europa
design didn't have the interconnecting bar between the sockets, and the
original structure is not really that strong with respect to pulling and
pushing forces.
Frans
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