During Visual Flight Rules (VFR) flight, the turn coordinator is used to help execute smooth banking turns at standard rates. When the wing of the plane on the gauge dips down to align with the bezel mark, that lets you know you are making a standard rate turn.
If your miniature plane’s wing stays above the standard rate mark, your turn is less than the standard rate. If the wingtip drops below the mark, you’re turning faster than standard.
A standard rate turn is 3 degrees per second. If you hold your aircraft in a standard rate turn, it will take one minute to make a 180-degree turn and two minutes for a 360-degree turn.
Why is a standard rate of turn important? For one thing, knowing how to execute a standard rate turn means you’re prepared to fly a reverse course if your VFR flight unexpectedly encounters Instrument Flight Rules (IFR) conditions. All you need to do is perform a 1-minute coordinated turn which will turn your aircraft 180 degrees and out of IFR weather.
Performing a level turn
Pre-turn checks
- Ensure you are at a safe height and airspeed.
- Check for other traffic in the area.
Initiate the turn
- Use the stick or yoke to apply aileron input in the direction of the turn. Neutralise the control when you have achieved the desired angle of bank. The airplane will remain at that angle.
- Gradually apply rudder in the same direction to coordinate the turn and prevent adverse yaw.
Bank angle
- Use the control to maintain a bank angle of about 30 degrees for a standard level turn.
- Monitor the turn rate. A standard rate turn is approximately 3 degrees per second.
Maintain altitude
- As you enter the turn you may need to add a bit of back pressure on the controls to counteract the loss of vertical lift due to the bank angle.
- Adjust throttle as necessary to maintain airspeed and altitude.
Levelling off
- To exit the turn, gradually reduce the bank angle to return to level flight. Start by reducing aileron input and coordinating with rudder.
- As you level off, gently pull back on the yoke to maintain altitude.
Post-turn checks
- Once level, ensure that your heading is correct and that your airspeed is maintained.
- Scan for traffic and adjust your flight path as necessary.
Tips for successful level turns
- Practice coordination: Properly coordinating the aileron and rudder inputs is crucial for smooth turns.
- Monitor instruments: Keep an eye on your altimeter and airspeed indicator during the turn.
- Avoid overbanking: Be aware of the increased load factor in steeper turns, which can lead to a stall if not managed correctly.
- Use visual references: Use the horizon to help maintain level flight during the turn.
Using the turn coordinator
The inclinometer measures yaw, which is the side-to-side movement of the aircraft’s nose.
In straight-and-level flight, the ball in the inclinometer rests at the lowest point of the tube, centered between the reference lines, due to gravity. To maintain coordinated flight, the ball should stay centered.
If the ball drifts off-centre, use the rudder to correct it. Apply rudder pressure on the side where the ball is deflected to bring it back to center. A simple rule to remember is, ‘Step on the ball’, to guide which rudder pedal to press.
When the ailerons and rudder are properly coordinated during a turn, the ball stays centred. If aerodynamic forces are unbalanced, the ball will shift.
In a slip, the turn rate is too slow for the bank angle, causing the ball to move inside the turn.
In a skid, the turn rate is too fast for the bank angle, and the ball moves outside the turn.
Correcting Slips and Skids
To correct a slip, decrease the bank and increase the rate of turn.
To correct a skid, increase the bank or reduce the rate of turn.
The phrase ‘step on the ball’ helps in making adjustments for better coordinated flight.