4
Balancing the model
- The Centre of Gravity (C.G.) is located 40 mm aft of the
leading edge at the wing root (see Fig. 9).
- Support the model at the marked points and allow it to
hang freely. Ideally the model will now balance level, with
the nose inclined slightly down.
- Adjust the position of the flight battery if necessary.
- Mark the battery location in the fuselage, so that you can
be confident of replacing it in the same position after remo-
ving it.
Operating the model
If you are using a robbe/Futaba radio control system please
reverse the throttle channel before operating the model for
the first time.
Routine pre-flight checks
Check the channel assignment at the receiver, and
swap the plugs over if necessary.
- Set the transmitter sticks and trims to centre.
- The control surfaces should now also be at centre (neu-
tral). Adjust the clevises if necessary.
- Make any fine corrections required at the transmitter.
- Check the direction of rotation of the servos.
- Stand behind the model. When you move the rudder stick
to the right, the rudder (if fitted) should also deflect to the
right.
- Pull the elevator stick back towards you, and the rear edge
of the elevator should rise.
- When you move the aileron stick to the right, the trailing
edge of the right aileron must rise, the left aileron fall.
- If any function works the wrong way round, correct it using
your transmitter's servo reverse facility .
- Set the control surface travels to the stated values, refer-
ring to the radio control system instructions.
Checking the power system
- Hold the model in such a way that the propeller is free to
rotate. Caution: Whenever you are working on the power
system (for installation, set-up or maintenance), keep well
clear of the rotational plane of the propeller - injury hazard.
- Check the direction of rotation of the motor. The propeller
must turn anti-clockwise when viewed from the front. If this
is not the case, swap over two of the three power wires
between the motor and the speed controller.
- After landing, and after every test-run, always discon-
nect the flight battery from the speed controller first,
then switch the transmitter off.
Building and Operating Instructions - Grob G 120TP Nano-Racer
No. 2598
Test-flying, flying notes
- Read the sections in the Safety Notes entitled “Routine
pre-flight checks” and “Flying the model” before attempting
to fly the model for the first time.
- For your initial test-flights please wait for a day with no
more than a gentle breeze.
- A good flying site consists of a large, flat, open grassy field,
devoid of trees, fences, high-tension overhead cables etc.
- Repeat the check of all the working systems.
- The model is designed to be hand-launched.
- The model must always be launched directly into any wind.
- Ask an experienced modelling friend to hand-launch the
aircraft for you. He should be capable of giving the model
a reasonably strong, flat launch.
- With the motor running at full-throttle, give the aeroplane a
firm launch directly into any breeze, with the fuselage and
wings level.
- Keep the model flying straight and level at first; don’t initi-
ate a turn while it is still close to the ground.
- Adjust the control surface trims if necessary, so that the
model flies straight with a reasonable rate of climb “hands
off”.
- Check the model's response to control commands. You
may need to increase or reduce the control surface travels
after the first landing.
- Check the aeroplane’s stalling speed at a safe height.
- Keep the model’s speed well above the stall for the landing
approach.
- If you needed to adjust the trims during the test-flight, cor-
rect the length of the appropriate pushrod once the model
is back on the ground, then return the transmitter trims to
centre so that full trim travel is available to both sides of
neutral for subsequent flights.
