Earlier, "Bert Willing"
wrote:

In any case you will have a blind
bonding applied to one side, be is spar
web to spar cap, or spar cap to wing
skin - that's the backdraw of using
negative moulds.

Now if you produce voids in one case,
you might as well produce voids in
the other case, no?...

Well, no, I don't see it that way.

The loads between the skin and the spar are far lower than the loads
between the shear webs and the spar caps. Also, the stiffening of the
spar caps against buckling is absolutely critical to the itegrity of
the spar. Voids between the shear web and the spar cap leave the cap
much more vulnerable to buckling.

Bob K.





And, by the way,
how much would you allow the price of a
glider to increase in case the the
manufacturer goes for x-ray or ultrasonic
QC?

--
Bert Willing

ASW20 "TW"


"Slingsby" a écrit dans le message de
om...
Still, the use of
Graphlite rods instead of carbon fibre rovings, and externally built
spars which are then wrapped in fibreglass cloth and vacuum-bagged is
a method which produces stronger, more durable and longer lasting
wings. As the current fleet of German gliders gets older I'll wager
there will be a lot of speed limiting directives because the "margin
of error" isn't what they thought it would be.
What kind of spar construction methods do the SparrowHawk, Apis and
Russia gliders use?