On Fri, 26 Jul 2019 10:39:48 -0700, John Foster wrote:

On the Phoebus (1st fiberglass production glider), the pin goes through
the spar of both wings at the centerline, but also through the bulkhead
behind the pilot's head. But this isn't a structural connection to the
fuselage though, I don't think. The main connection is through the lift
pins, even on this early model. And the wing is VERY stiff, so not much
flex at all.

Sailplanes 1945-1965 by Martin Symonds says that the Phoebus was closely
based on the Phonix (the first glass glider) and has a good drawing of
the wing mount (page 253).

This shows sharply tapered wing stubs that fit into a close fitting
structure built into the fuselage. The wings were pulled together by a
single, double-threaded bolt with opposite threads on each end and driven
by a (hex?) flange in the center. The axis of this is at right angles to
the fuselage centre line, so rotating it pulls the wings together and the
stubs into close contact with the matching fuselage structure.

There are two lift pins on each side of fuselage, which appear to lock
into the wing stub support structure. The pins project outwards to fit
into sockets on the root ribs.


--
Martin | martin at
Gregorie | gregorie dot org