Lab
Library
Journal
Shop
Sign in
to keep
Share image
1
165
The Aeroplane Speaks. Fifth Edition
·
H. Barber
116
However
carefully
the
above
adjustment
is
made,
there
is
sure
to
be
some
slight
error.
This
is
of
no
great
importance,
provided
it
is
divided
equally
between
the
left-
and
right-hand
wings.
In
order
to
make
sure
of
this,
certain
check
measurements
should
be
taken
as
follows:
Each
bay
must
be
diagonally
measured,
and
such
measurements
must
be
the
same
to
within
1/16
inch
on
each
side
of
the
aeroplane.
As
a
rule
such
diagonal
measurements
are
taken
from
the
bottom
socket
of
one
strut
to
the
top
socket
of
another
strut,
but
this
is
bad
practice,
because
of
possible
inaccuracies
due
to
faulty
manufacture.
The
points
between
which
the
diagonal
measurements
are
taken
should
be
at
fixed
distances
from
the
butts
of
the
spars,
such
distances
being
the
same
on
each
side
of
the
aeroplane,
thus:
The
above
applies
to
both
front
and
rear
bays.
It
would
be
better
to
use
the
centre
line
of
the
aeroplane
rather
than
the
butts
of
the
spars.
It
is
not
practicable
to
do
so,
however,
as
the
centre
line
probably
runs
through
the
petrol
tanks,
etc.
THE
DIHEDRAL
BOARD.--Another
method
of
securing
the
dihedral
angle,
and
also
the
angle
of
incidence,
is
by
means
of
the
dihedral
board.
It
is
a
light
handy
thing
to
use,
but
leads
to
many
errors,
and
should
not
be
used
unless
necessary.
The
reasons
are
as
follows:
The
dihedral
board
is
probably
not
true.
If
it
must
be
used,
then
it
should
be
very
carefully
tested
for
truth
beforehand.
Another
reason
against
its
use
is
that
it
has
to
be
placed
on
the
spars
in
a
position
between
the
struts,
and
that
is
just
where
the
spars
may
have
a
little
permanent
set
up
or
down,
or
some
inaccuracy
of
surface
which
will,
of
course,
throw
out
the
accuracy
of
the
adjustment.
The
method
of
using
it
is
as
follows:
Marker
Marker
Fine marker
White-out
Fine white-out
Circle
Paint
Unmarker
Hand
Scalpel
Dice
Sieve
Purify
Undo
Redo
Start over
