very important
that
the
throttle
be
advanced
slowly. This allows the
air-
plane to start
rolling
before
high RPM is
developed,
and the gravel
will
be blown
back
of the propeller rather than pulled into it. When unavoid-
able
small dents
appear
in the propeller
blades,
they should be immedi-
ately corrected as
described
in Section V under propeller
care.
Prior
to take-off from fields
above
3000
feet
elevation, the mixture
should be leaned to give maximum RPM in a
full-throttle,
static runup.
WING
FLAP
SETTINGS.
Normal
and
obstacle
clearance
take-offs are performed
with
wing
flaps up. The use of 10" flaps
will
shorten the ground run approximately
10%, but this advantage is lost in the climb to a
50-foot
obstacle.
There-
fore, the use of 10° flaps is reserved for minimum ground rims or for
take-off from soft or rough fields. If 10° of flaps are
used
for minimum
ground runs, it is preferable to
leave
them extended rather than retract
them in the climb to the
obstacle.
In this
case,
use an
obstacle
clearance
speed
of 65 MPH. As
soon
as the
obstacle
is cleared, the flaps may be
retracted as the airplane
accelerates
to the normal flaps-up climb
speed
of 80 to 90 MPH,
During
a high altitude take-off in hot weather where climb would be
marginal
with
10° flaps, it is
recommended
that
the flaps not be
used
for
take-off. Flap settings greater than 10° are not
recommended
at any
time
for take-off.
PERFORMANCE
CHARTS.
Consult the Take-Off Data chart in Section VI for take-off
distances
imder various
gross
weight, altitude, headwind, temperature, and
run-
way
surface
conditions.
CROSSWIND
TAKE-OFFS.
Take-offs into strong
crosswinds
normally are performed
with
the
minimum
flap setting
necessary
for the field length to minimize the
drift
angle immediately after take-off. The airplane is
accelerated
to
a
speed
slightly higher than normal, then pulled off abruptly to prevent
possible
settling
back
to the runway while
drifting.
When clear of the
ground, make a coordinated
turn
into the wind to correct for
drift.
2-13
To Next Page