Frans,
> 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.
>
When you fly with the engine pulling on the fuselage (cannot pull on the
wings in the Europa!), the fuselage pulls the wings.
When you glide, I don't know which part (fuselage or wings) have the best
weight/drag ratio, so I don't know whether the fuselage wants to leave the
wings behind or vice versa (I do suspect, though, that the wings are holding
back the fuselage).
At unusual attitude or high G-loading, it has been stated on this forum that
wings (on other airplanes) have moved forward when they broke off. This
means that there has been a forward (centerline direction) net force acting
---From the wings onto the fuselage at that time, in addition to a
perpendicular (to centerline) component, of course.
> 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.
>
Except in very uncommon circumstances, the rear wing pins on Europa are
pushing backwards on the fuselage-mounted sockets, and tries to bend in the
fuselage sides/compress the cross tie bar between the left and the right
side sockets, as the wings have a resultant force going back and up during
normal powered flight. Whether the resultant force can ever be directed
forward of the perpendicular to the centerline in the Europa, I have no idea
- but I will keep the pins in, just in case!
>
> 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, please promise that you will not be the first one to try that!!
/////////
I prefer to end my limited contribution to this tread now, but look very
much forward to picking it up again over a cold beer at the Vichy fly-in.
Perhaps also the beer's force may be determined by which way we are leaning
..?
Regards,
Svein
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