Lesson One – Circuits

Learning Objectives

  • Be able to fly a square left & right-hand circuit of good size, shape and orientation
  • Maintain a constant altitude whilst flying in the circuit
  • Understand how control inputs effect the models flight attitude

Flying the Circuit

  • Your instructor will handle all take-off and landings

A circuit is the most basic pattern of flight used in all forms of aviation.  It is a rectangular flight-path, flown at a constant altitude with the upwind leg flown along the centreline of the runway and into wind.  It is designed and positioned like this so that other aircraft that are taking off or landing are able to do so safely without fear of colliding with another airborne aircraft.
Once your instructor has got the aircraft airborne and flying straight and level in the circuit he will hand you the controls on the downwind leg.  From here you will need to make a series of 90° turns to keep the aircraft in the circuit pattern.
Do not adjust the throttle at this point.  Concentrate on using aileron and elevator to make a smooth turn as follows:

  • Use aileron to bank the aircraft left or right.  Move your right thumb left to bank left and vice versa.
  • Use a small smooth movement to roll the wings about 20-30°, the aircraft will start to turn
  • Now, as the aircraft begins to turn, use small amounts of up elevator to keep the nose from dropping and keep a constant altitude throughout the turn
  • As you reach the end of the turn, use the ailerons to roll the wings level again

The use of elevator is important in the turn to maintain altitude.  Without it the nose will drop and the aircraft will start to dive in a spiral motion towards the ground.  Using the elevator like this is called ‘supporting the nose in the turn’.
Most circuits at the LMMAC field are made in an anti-clockwise direction but we will practice both.

Using the Throttle

As you become more proficient at flying the circuit pattern we will start to introduce throttle to control the altitude of the aircraft.
Most trainers are set up to have ‘positive stability’.  This means they are designed to fly, when correctly trimmed, straight and level at a set speed.  (Your instructor will get the plane flying like this before the lessons begin).  If this straight and level is disturbed by a control input, the aircraft will try to return to this straight and level state.  We can take advantage of this by using the throttle to force the aircraft to climb or descend.
If you feel the aircraft is descending in the circuit.  Move the throttle up by a couple of clicks, this will cause the nose of the aircraft to lift as the wing generates more life and climb slowly.  If the aircraft is climbing too high, reduce the throttle a little and let it descend slowly back down to the desired altitude.
Later on we will use this throttle control to help us climb after take-off and descend to the runway for landing.

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