J. Perkins TWISTER BELL 47, Manual

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Twister Bell 47
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Twister Bell 47
FLIGHT TRAINING GUIDE
The flying area
The flying area should be indoors in a large room
or a hall or office. In this room you should have all
doors closed as any wind can affect the movement
of the Twister Bell 47.
Make sure the take-off floor has a smooth surface
rather than carpet which can trip up the Twister Bell
47 during ground handling.
WARNING!
You should be aware that the main rotor blades
spin at a high rpm and are capable of inflicting
serious damage to objects, people and animals.
You must take care when you are flying and make
sure there are no children or animals in the room or
flying area.
In addition, make sure the flying area is large
enough and contains no obstacles (such as
furniture) which could be hit while you are learning
to come to terms with the flight characteristics of
your Twister Bell 47.
POSITIONING YOUR TWISTER BELL
47
First, double check that all the controls are working
and operating correctly.
Place the model in the middle of the room.
Position yourself at least 2 metres behind the
helicopter and slightly off to one side so that you are
able to see the nose of the helicopter.
Useful tip ........................... Please note when flying
that you must always watch the nose of the
helicopter. If the nose of the helicopter yaws to the
left, you must apply right tail rotor to correct this by
pushing the tail rotor stick to the right.
INCREASE THROTTLE GENTLY
Watch the nose and apply just enough throttle until
the model becomes light on its skids.
Useful tip ........................... All helicopters exhibit a
degree of instability when approaching take-off as
friction from the ground is reduced as the helicopter
gets nearer to 'unsticking' from the surface.
Observe whether or not the helicopter is tending to
move forwards or backwards.
If it tilts forward, you will need to apply rear elevator
(rear cyclic) trim to correct. And vice versa if the
Twister Bell 47 tends to tilt backwards towards you.
Observe the helicopter about the roll axis and adjust
the trims in the same way–if it tends to roll or hop to
the left, apply a little right roll trim and vice versa.
Adjust the trims until the Twister Bell 47 shows no
detectable forward, backwards or sideways drift
tendencies.
Useful tip ........................... When applying throttle,
you must apply it gently and in small amounts.
At this stage the Twister Bell 47 MUST STAY ON THE
GROUND!
Too much throttle will cause the helicopter to leave
the ground and you may have difficulty in bringing it
under control quickly enough to avoid tipping it over.
WARNING!
Too much throttle applied too quickly will cause
your helicopter to leap rapidly and uncontrollably
into the air!
Never apply too much throttle too quickly.
WALKING THE HELICOPTER
The helicopter should now be trimmed and you
should be in a position to start learning to 'take your
Twister Bell 47 for a walk'.
These first flights should be made with the Twister
Bell 47 in contact with the ground at all times.
Apply just enough power to make the helicopter
light on the skids and add a few clicks of forward
trim to tilt the rotor disc forwards.
Apply enough power so that the machine starts
to move slowly forwards. Watch for any change
of direction of the model and use the controls to
correct.
At this point, you will be able to check yaw
operation. Applying left yaw will tend to swing the
nose to the left and right yaw will swing the nose
right. Note that the on-board piezo gyro damps out
any tail direction changes and so stabilizes the
helicopter.
The aim now is to travel steadily and progressively
across the floor.
Walk forwards following the helicopter across the
floor whilst using the controls to maintain slow and
accurate progress.
The 'walking technique' is the method often used
to safely develop the automatic ability to apply
the right control input when needed. You should
practice this until you are starting to automatically
input the control commands required to keep the
helicopter moving gently forwards along the ground.
When you feel confident, proceed to the next step...
TAKING THE FIRST 'HOP'
By now you should be making the correct control
inputs automatically and be able to make smooth
progress across the surface of your floor.
If you cannot, please keep practicing!
The first 'hop' is a natural 'next step' from walking
your Twister Bell 47.
Whilst walking you apply a small amount of extra
throttle to briefly raise the helicopter off the floor
and into the air for a second. Then you should
reduce throttle and settle back onto the floor.
With practice, you will find that you are able
to make more and more of the correct control
commands required to keep your Twister Bell 47
upright and that the hops become longer and higher.
Always make sure you watch the nose of your
helicopter–not the tail. The gyro will keep the tail