This must be offset by altering the length of the
struts. The best way to proceed is to measure the distance
between the top and bottom spars by the side of each strut,
and if that distance, or ``gap'' as it is called, is not as stated
in the aeroplane's specifications, then make it correct by
changing the length of the strut. This applies to both front
and rear interplane struts. When measuring the gap, always
be careful to measure from the centre of the spar, as it may
be set at an angle, and the rear of it may be considerably
lower than its front.
BORING HOLES IN WOOD.--It should be a strict rule that
no spar be used which has an unnecessary hole in it. Before
boring a hole, its position should be confirmed by whoever
is in charge of the workshop. A bolt-hole should be of a size
to enable the bolt to be pushed in, or, at any rate, not more
than gently tapped in. Bolts should not be hammered in, as
that may split the spar. On the other hand, a bolt should not
be slack in its hole, as, in such a case, it may work sideways and
split the spar, not to speak of throwing out of adjustment
the wires leading from the lug or socket under the bolt-head.
WASHERS.--Under the bolt-head, and also under the nut,
a washer must be placed--a very large washer compared
with the size which would be used in all-metal construction.
This is to disperse the stress over a large area; otherwise
the washer may be pulled into the wood and weaken it,
besides possibly throwing out of adjustment the wires
attached to the bolt or the fitting it is holding to the spar.
Pages:
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121