Raytheon Beech Baron E55 - Page 279

Raytheon
Aircraft
BEECH
BARON
55
AND
58 SHOP
MANUAL
BALANCING
PROCEDURE
COUNTERBALANCING
METHOD
a.
Locate
the
chord line
by placing
a
straightedge
at
the
lower
closure
rib
of
the rudder
so
that
one
end
is
aligned
with
the
center
of the
torque
tube
while
the
other end
is
centered
on
the
trailing
edge.
Mark the chord
line with
a
suitable
marker,
such
as
a
grease
pencil,
then
remove
the
straightedge.
b.
Secure
the
trim
tab
position
in
its
neutral
position
with
a
small
piece
of
masking
tape.
c.
Fit
the
correct
sized
bolts
in
the
hinge
brackets
and
mount
the
rudder
on
the
knife-edge
supports.
Ascertain
that
the
rudder
is
free
to
rotate
about
the
hinge
line.
d.
To
determine
if
weight
should
be
added
or
removed,
suspend
a
paper cup
from
a
point
near
the
center
of
the
rudder
trailing
edge
if the
balance
is
nose
down
or
near
the
center
of
the
leading edge
if
the balance
is
tail
down.
Use
a
short
length
of
small-diameter
string
secured
to
the
surface
with
a
small
piece
of
masking
tape
as
illustrated
in
Figure
4-27.
The
cup
must
be
free
to
hang
vertically.
e.
Add
small
quantities
of lead shot
to
the
cup
until
the
rudder balances
with the chord
line
level.
Check
this
by
holding
a
spirit
level
aligned
with the
marked
chord line.
f.
The
distance
D
must
be
perpendicular
to
the
hinge
line.
Measure
D
from
the
hinge
line
to
the
suspension
point
of
the
cup.
g.
Remove
the
cup,
contents,
and
string,
then
weigh
them.
NOTE
Since
any
weighing
error
is
magnified
by
the distance
D,
weighing
is
most
important
and
must
be
done
carefully
on
scales that
are
certified
for
accuracy.
h.
Calculate
the
static balance
as
follows:
1.
The
weight
of
the
cup
and
contents
is
designated
by
W.
2.
The
over:
or
underbalance
moment
is
designated by
M.
3.
M=WxD
4.
The
following
is
a
typical
example
of
a
balancing
calculation:
Assume
the
rudder
was
slightly
underbalance
(tail
heavy)
and the
paper
cup
was
suspended
from
the
leading
edge.
If
the rudder balances with
the
chord
line
level
at
W
0.35
pound
and D
10.0
inches
then...
M
0.35
x
10.0
M
3.5
inch-pounds
In
this
instance,
M
is
within
the
required
static
balance
range
and is
therefore
acceptable.
i.
The
complete
rudder
assembly,
painted
or
unpainted,
including
the
control
arm
and with
or
without the
bellcrank
attached,
must
not
be
tail-heavy
over
a
maximum
moment
(see
RUDDER BALANCING for
applicable
airplane
se-
rials
and
maximum
moments).
If the
static
balance
does
not
comply,
remove
the
rudder-horn
weight
and
add
or
re-
move
solder
to
bring
the
rudder
balance
within
required
limits.
NOTE
Coat the
weight
with
a
corrosion
preventative
material such
as
zinc
chromate
primer
to
insulate
the
dissimilar
metals.
Replace
the
rudder
horn
weight
and recheck
the rudder balance.
E16
4-71