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Twister Medevac
how doeS a helicopteR fly?
A helicopter must be controlled about 4 axes simultaneously; yaw, pitch, roll and height. Your transmitter
has 2 dual-axis precision stick units with two controls on each stick.
In a throttle left (mode 2) transmitter
The left stick controls height (climb or descent) and tail rotor controls yaw (left or right).
The right stick operates the cyclic steering controls which are used to pitch the helicopter nose
up/nose down and to roll the helicopter left or right.
In a throttle right (mode 1) transmitter
The right stick controls height (climb or descent) and cyclic aileron control to roll the helicopter left
or right.
The left stick operates the tail rotor controls yaw (left or right) and cyclic elevators controls which
are used to pitch the helicopter nose up/nose down.
The revolutionary contra-rotating sytem used in the Twister Medevac transforms helicopter flight by
making control so easy that the helicopter almost flys itself!
Transmitter stick movements
Helicopters require relatively small control inputs of relatively small duration. Do not move the sticks to
extreme positions. A delicate touch is required on the sticks. The sticks should be allowed to return to
neutral almost immediately after a control input is made. If you watch an experienced pilot hovering his
helicopter, you will see that his transmitter sticks hardly move. This is the goal you will be working towards
in this guide.
Height control
A helicopters rotating wings - the rotor blades, generate lift, in the same way that a propeller generates
thrust. The lift generated by the main rotor blades increases as rotor speed rises causing the helicopter to
climb. Conversely as the main rotor speed is reduced, the helicopter descends.
This method of helicopter height control is called 'fixed pitch'.
Height is managed using the throttle stick of your transmitter.
Push forward to climb, pull back to descend.
Yaw control
Yaw control is achieved by altering the speed of one main rotor relative to the other which causes a
change in the torque generated by the main rotor and hence a rotation to left or right about the main rotor
shaft.
When a helicopter is in the hover it can be yawed left or right.
Push the rudder stick left to yaw the nose of the helicopter to the left and push to the right to yaw the nose
right.
Your Twister Medevac helicopter is fitted with a micro piezo gyro and electronic mixing system which
automatically helps stabilise the tail making for much easier flight.
Steering control - fore and aft cyclic
When hovering, a brief forward push on the cyclic control stick will tilt the rotor disc forward causing the
helicopter to move off in that direction. Pull the stick back gently to stop it. If you pull the stick back further,
you start flying backwards.
Steering control - roll cyclic
When hovering, a brief right control stick movement will roll the rotor disc to the right and the helicopter
will start moving to the right. By briefly moving the stick to the left any right drift or movement will be
arrested or reduced.
Mastering the hover
Both experienced model and full-size helicopter pilots in the hover will gently 'nudge' the cyclic controls
automatically in order to keep their helicopter in one spot and prevent it from moving away from that spot.
A large part of the initial learning phase in helicopter flight is about mastering the cyclic controls and
learning to hover. Control commands will become 'instinctive' when you have 'mastered' the hover.
