Turning

This lecture is about turning the aircraft safely. You might ask why? It is simple to do. The answer is very simple. A bad turn will result in a Stall or a Spiral Dive. Both are normally fatal if near the ground.

Most turns are done at what we call a rate 1 turn rate . (Especially used when instrument flying.) 

At other times 25 degrees of bank may be used to turn 90 degrees.( such as flying in the circuit) When Circling over an object 45 degrees may be used.

A Rate 1 Turn = 180 degrees heading change in one minute.

The Rate 1 turn bank angle is governed by the speed of the aircraft at the time the turn is commenced.( Normally about 15 degrees in a Cessna)

The formula to work this out is simple.
Drop the last figure off of the airspeed you are doing and add 7 to the first figure. 

Example you are doing 80 knots, take the zero off this leaves you 8, add 7 to the 8 this equals 15. Therefore 15 is your bank angle. (The maximum bank angle for an airliner is normally  25 degrees.)

To judge this bank angle you need to look at the artificial horizon. If you look at the 12 O clock position of this gauge, you will see the gauge is marked at the top with lines either side of the centre .These lines  represent 10 degrees  bank angle per line, up to 30 degrees of bank.

As you turn the aircraft you may also need to pull back on the stick slightly so you do not lose height.. You do not need to retrim as soon you will be rolling the aircraft level again. The skill here is to roll the aircraft out exactly on the required heading. This is to stop having  to keep zigzagging  to get the heading right . The steeper the turn the earlier you have to roll out . On average you should roll out of the turn 5 -10 degrees before the required heading.

You should roll in and out of the turns very gently . Normally you use the Direction Indicator to judge the turn out. This instrument is gyro driven .A compass lags behind and makes it difficult to judge. The compass is  affected by changing speeds. a gyro is not. You must check the gyro is set to the compass at all times a check should be made on a regular basis of at least every 15 minutes as the DI will wonder off course.

The reason you may have to pull back on the stick is because lift in a turn has to turn the aircraft as well as keep the aircraft flying. This happens in two ways. the vertical one to keep the aircraft flying and a horizontal one to pull the aircraft into the turn.

Aircraft with High Wings like the Cessna

 The pilot should before commencing the turn lift the wing slightly by turning the opposite way so that he can check the blind spot  in the turn direction. This  prevents from turning into the path of another aircraft.

Remember  the more tighter the turn the more chance of stalling and spinning as the stall speed increases.

Practice now by turning ninety degrees and rolling out on the heading. try them first to the left and then to the right. Do not gain or lose height.

Turns greater than 25 Degrees of Bank

Normally the pilot will have to add power as well and give more back pressure on the joystick.  As the pilot rolls out level he would reduce the power again and ease the stick forward.  You have all heard of G force this is the weight therefore more power is needed to compensate.

 If done incorrect , it is a stall or spiral dive as the end result .

Climbing Turns

Climbing Turns should never be more than  a rate one turn. Be prepared for pushing the joystick in the opposite direction to stop the aircraft  over banking.   This is caused by the inner wing in the turn having less angle of attack than the outer wing which is producing more lift.

Descending Turns

You will have to hold the bank on in the turn this time in . The inner wing has more angle of attack than the outer this time. Be very careful not to over bank  the aircraft during turns. Keep a good lookout for other aircraft as well as watch your gauges.

If you apply the rules above then you will be a safe pilot.

Now practice descending turns and climbing turns. When you are happy with that we can go in the circuit and practice all the skills learnt so far.

Use the DI for rolling out on your headings  Later we will use the compass and isolate the DI from working. This will be covered in the instrument rating course.

Remember the rules Rate 1 turn in the climb  and no more than 25 degrees of bank in other normal  movements. Again Watch your height and airspeed. Look for other aircraft.

The Spiral Dive

If you find your airspeed increasing in a descent, and your aircraft is banked sharply, and you have power on and  the altimeter and VSI showing a rapid descent rate, you are in a spiral dive. 

To recover from this fatal situation you should close the throttle, roll the aircraft level , then pull back gently on the stick (so as not to overstress the aircraft) until the aircraft levels out of the dive.  Once sorted out  re commence descent or climb as required. Check your trim and your heading. You will also find during the spiral dive the Direction Indicator going round.

You will now have gathered the difference between the Stall and the Spiral dive is airspeed. What they have in common are they are both dangerous and both caused by bad pilot handling normally (unless you are an airshow display pilot.). Knowing what your aircraft is doing all the time is a good insurance policy. Use the instruments to get an  early warning. One cause of the spiral dive is the pitch is to low so watch this at all times.

Armed with all the information now you are ready to fly in the circuit and practice.

Index