16
Again, as shown, the battery pack, in place in the battery tray, now
sits directly behind the motor with a piece of scrap 1/4" balsa in
place to keep it from shifting. This "fix" works well when using
lighter motors and is far superior to adding weight to achieve
proper balance.
Once you have achieved the proper 2-1/2" C.G. location by shifting
the battery as needed, mark and note the battery location onto the
battery tray to ensure that it is installed and retained in the proper
position, every time the model is flown.
CONTROL MOVEMENTS:
The Bf-109 is a fighter plane and as such, is designed to be
responsive to your control inputs. It is very important to set your
model up to these recommended throws, for the first flight, to avoid
any nasty surprises, especially on elevator. Set the throws as
close to these specifications as possible mechanically by moving
the linkages in or out on the servo arms and control horns, then
fine tune these throws with the adjustments available in the
transmitter.
Recommended Initial Control Movements:
ELEVATORS:
1/2" (12 mm) up and down
AILERONS:
3/8" (9.5 mm) up and down
RUDDER:
7/8" (22.25 mm) left and right
FLYING:
If you have carefully followed this assembly manual, you should
have no real problem test flying your Bf-109.
We suggest
choosing a calm day for the first flights. Such conditions always
help in correctly evaluating the flight performance of the model.
If you have built your Bf-109 model without landing gear, the
requirement is, of course, to hand-launch the airplane.
The
hand-launch can be done by a friend and, with a little experience,
you can also learn to launch the model by yourself. To properly
hand-launch a low-wing model like the Bf-109, the fuselage is
firmly gripped just behind the wings. The airplane should be briskly
launched straight ahead, directly into the wind, with the wings level
and the motor at high throttle.
The launch should be aimed
directly at the horizon - never hand-launch the model with the nose
up!
If you have built your Bf-109 model with the landing gear, then of
course, the airplane can be taken off from the ground. Arm the
motor and test the flight controls for correct movement. Hold up
elevator and taxi the model to get a feel for how it handles on the
ground. Make sure you have positive left and right turning ability.
If you don't, make any adjustments needed to achieve positive
ground control. Once you are satisfied with the taxi tests, line the
model up with the center of the runway with the nose pointed
directly into the wind.
Hold a little up elevator and smoothly
advance the throttle - do not throw the throttle fully open all at once!
The model should roll forward smoothly, tailwheel on the ground.
As is typical of this type of airplane, you will need to be ready with
some right rudder as you slowly release the up elevator and allow
the tail to rise. Allow the speed to build until a slight application of
up elevator breaks it free from the runway. Do not try to force it into
the air before it is ready to fly.
Once the airplane is airborne, maintain a straight outward flight
path, climbing at a shallow angle, until a safe maneuvering altitude
is reached. If the model requires trim input, fly to a reasonable
altitude before attempting to make any changes.
Make your
control inputs smooth and avoid jerking the sticks. At trimming
altitude, bring the throttle back to about a 2/3rds setting for cruise
speed and then, begin fine-tuning any required trims. What you
want to achieve is a straight and level flight path without
transmitter corrections.
Once you're comfortable with the way the model is flying, make a
few circuits around the field, getting a feel for the controls. If the
airplane is properly trimmed, it should demonstrate smooth flight
characteristics, without any jumpiness or over sensitivity.
At
altitude, try an axial roll. Next, try another roll in the opposite
direction. The Bf-109 should roll smoothly in each direction. Next,
try a simple inside loop. Choose your entry heading and go to full
throttle. Pull up smoothly until the airplane is inverted, then back
off the throttle as it comes down the backside of the loop.
Consecutive loops are easily done using the same technique. This
maintains a steady airspeed and conserves battery power. Still at
cruise speed and reasonable altitude, roll the model inverted. A
properly balanced model will take very little down elevator to
maintain inverted flight.
By now, you should be getting comfortable with the handling of
your Bf-109. Fly the airplane up to a safe altitude, flying directly
into the prevailing wind.
Throttle back the motor to become
familiar with the slow flight characteristics of the model. Still at a
lower throttle setting, make a few dummy landing approaches,
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