On Sep 18, 6:44*pm, Eric Greenwell wrote:
wrote:

JJ - thank a lot for looking inside the wing - you are one of the few
guys here in a position to do it. I know I'm on my own responsibility
on this - but I feel a bit better knowing that there is some decent
structure in there.

Since the spoilers have to survive opening at Vne, I imagine there is
*very* decent structure in there.

I prefer to use a strap that engages both pivots in the spoiler box,
because it spreads the load to each pivot, and has twice as many straps
to spread the load pressing on the wing surface.

--
Eric Greenwell - Washington State, USA
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Makes sense Eric. Although the air loads at Vne exert slightly
different forces and moments than the tiedown strap - it is still a
lot of tugging and twisting on the pivots. In a 90-degree dive at
terminal velocity the drag equals the weight. I presume a whole lot of
that drag comes from the flat plate drag of the divebrakes. If you
also consider that you have to be able to open the divebrakes at Vne,
that's a pretty big impulse load.

I have some other practical considerations for tying to one pivot -
but I'm not too worried now.

9B