Tailwheel Aeroplane Techniques
Michael Peare

Introduction:

In the air all aeroplanes obey the same rules and fly in similar ways to each other, but on the ground tailwheel and nose wheel aeroplanes are quite different. It is not necessary for you to be an ace pilot to fly one of these tailwheel aeroplanes, all that is required is due care and attention.

Due care means that you do not exceed your own limitations, or those of the aeroplane, read the manual and note the crosswind limits, but know your own limits as well

Attention means that you stay alert and fly the aeroplane, remember that the flight is not finished until the aeroplane is either tied down or in the hangar.

Basics:

The first problem with a newcomer to tailwheel aeroplanes is over-control, modern American training aeroplanes have insensitive controls, but most tailwheel aeroplanes have very sensitive and/or effective controls, so build up your control inputs from small ones rather than start from large inputs which lead to necessarily massive corrections.

For a tailwheel aeroplane to sit in the correct three point attitude it is necessary for the centre of gravity to be behind the main wheels, in other words the concentration of weight is behind the wheels.

In any deceleration the weight behind the wheels would prefer to be ahead of the wheels, and therefore threatens you with the 'ground loop'. To combat the ground loop the aeroplane has a 'rudder'.

On the front of a tailwheel aeroplane there is usually a carved plank or twisted piece of metal known as a 'propeller', the propeller spins the air around and sends it backwards in a spiral. The problem with this spiral is that when the throttle is opened the spiral strikes the fin causing the aeroplane to swing, the answer to this problem is to use the 'rudder'.

The down going propeller blade has a greater angle of attack than the up going blade while the tailwheel is in contact with the ground during the initial roll. The down going blade having a greater angle of attack may develop more thrust than the up going blade. This 'asymmetric blade effect' aggravates the situation as well.

As the aeroplane accelerates to flying speed it is necessary for the tail to be lifted to the flying attitude, this puts the rudder into the slipstream for better directional control and gives you a better view of your takeoff path. Unfortunately the propeller at this point decides that it is also a gyroscope. As you lift the tail you also change the angle of the rotating propellers' disk, and in its guise of gyro the propeller precesses and swings the aeroplane off the straight and narrow; to combat this use the 'rudder'.

The general rule is (in a normal tractor aeroplane) if you sit behind the propeller and the top blade rotates left then you will need left rudder to combat swing on takeoff, if it rotates right (American) then right rudder is needed. Crosswinds can modify this rule.

From the above you may have realised that the 'rudder' is going to be very important to you.

Prior To Flying:

Now we are ready to go flying, our walk towards the tailwheel aeroplane allows us to size it up.

Does it have a full stall landing attitude?...In which case there is going to be more swing as we lift the tail and we are going to have to be very patient in the landing hold off until the aeroplane is ready to land.

... or is the attitude shallow making for faster landings and longer roll-outs.

Is the aeroplane short coupled? How much rudder area has it got? Look at the aeroplane and estimate its qualities.

Give the aeroplane a thorough inspection, especially the landing gear.

What sort of shock absorption has it got? Bungees and springs tend to launch you back into low orbit, spring steel tends to wobble you in all directions, rubber blocks tend to jar the back, unless you get it right of course.

The tailwheel takes a real bashing so inspect the spring attachments very carefully, especially the forward attachment bolt which should be snug.

Sitting in the aeroplane take the time to find all of the controls, switches and instruments, and then shut your eyes and touch them with your fingers. Familiarity gained prior to starting can save a lot of fumbling later. Look at the view from the cockpit, how much can you see? Will you need to weave in order to taxi along a clear path? Can you see what is to the right of the nose?.

Never be in a hurry to fly any aeroplane, take your time and ensure that everything is as it should be.

When you have fired up the engine and you are ready to taxi check all around is clear; ideally you will have placed the aeroplane in a position such that your slipstream will not blast another aeroplane or anything else fragile, and certainly not into an open hangar.
Pick a taxi path that allows you to see as much as is possible, and allows you to 'sail' out to the holding point without sharp turns which need brakes. Use of the brakes, and steering around one wheel is to be avoided.

Remember the attitude of the aeroplane and look for key view points to help you with the landing later on.

Be aware of the wind strength and direction and deflect the controls accordingly, remember that the controls work in reverse when the wind is from behind. If the tailwind exceeds the slipstream then the elevator control should be forward of neutral.

Getting Airborne

For takeoff, line up and pick an aiming point beyond the end of the runway in the direction of your takeoff. This aiming point will allow you to detect the slightest deviation from your track and allow you to correct the slightest swing with a dab of rudder.

Open the throttle smoothly with the stick back, then as the speed increases move the stick to just forward of centre and the tail should begin to rise. Keep the aeroplane straight by reference to the aiming point.

If you look at the markers at the side of the runway you will hit them!

If a swing develops dab in opposite rudder but do not hold it in, the aeroplane will respond very quickly and so you will need to anticipate the aeroplanes return to the straight and narrow with a dab of opposite rudder as it approaches.

With the aeroplane level and the airspeed approaching flying speed a gentle back pressure on the stick will result in the aeroplane leaving the ground when it is ready.

If there is a crosswind then the usual rules apply (aileron into wind etc.) and there may be benefits if the wind is opposite the direction of anticipated swing. This time, hold the aeroplane on the ground until sufficient airspeed is gained to make a clean break with the ground, and therefore avoid touching back down with a crab attitude.
Never takeoff tail low when there is a crosswind; the aeroplane may become airborne prematurely, and drift off the side of the runway. If there are obstacles, trees and bushes the aeroplane could be wrecked!

On soft fields or very rough fields a tail low attitude with the tailwheel just clear of the ground will facilitate a more comfortable takeoff if the wind is down the runway.

A rough field with a strong crosswind will therefore require a bit of pilot decision making!

[Some pilots advocate three point takeoffs, and tail low takeoffs, and many a Tiger Moth has come to grief with this technique. Be aware of the wind, and if you use this technique ensure that you accelerate in ground effect and not stall out by climbing too slow.]

Returning To Earth

The landing is commenced from the downwind leg of a circuit.
Set the aeroplane up such that it is trimmed for the approach before you turn base; the trim is the secret to a good approach.

On the base leg, throttle back as required and add flap (if fitted) as required, trim the aeroplane.

On final approach pay attention to accurate airspeed control, (avoid over control), ensure that the aeroplanes' attitude is sensible, and aim to approach power off (if the type allows). Initial flare will be measured by looking down at the ground to establish the correct height but thereafter you should look as far forward as is practical in order to keep the aeroplane straight and aligned, usually you will look in about the eleven o'clock region.

[The flare is the same for all light aircraft. As you approach the runway you watch how the sides open out. As you get closer the runway widens faster and faster, and we slow this widening down by raising the nose, and this is the flare. The approach and touch down in a Citabria is the same as it is in the Cessna 150 with 20 degrees flap selected. The roll out on the runway is different!
Every pilot sees the landing differently and so observe your instructor’s landings carefully.]

Again if you look at the markers at the side of the runway you will hit them.

Hold off just above the ground until the aeroplane reaches the three point attitude, (this should be remembered from when you taxied out), and then maintain this attitude to touchdown. Ideally you should try to touch down very slightly tailwheel first.

After touch down, continue to bring the stick fully back.

With the aeroplane safely on the ground, the weight behind the wheels, the slope of the ground, and the crosswind will all try to divert you from the straight and narrow and take you for a ride off the side of the runway.

Do not touch the brakes unless all is otherwise lost, use your rudder. Try to anticipate any swing with brief dabs of rudder of small deflection at high speed and greater deflections as the speed reduces, holding the rudder in any one position will create a large deviation in that direction.

As the speed reduces greater amounts of rudder are required (unless you're an expert), anticipate the swings and aim to stop the return swing to the direction you want before you get there.

The use of power may help to stop a swing but you must consider the direction that the slipstream will swing you, and the fact that power tends to accelerate you into whatever you are trying to avoid hitting.

Brakes tend to dramatically alter the direction of the swing with a violent swing in the opposite direction and/or putting you on your nose. Good brakes on a tailwheel aeroplane are not an asset.

As the speed reduces the time between control input and response increases.
Ground loops occur at the slowest speeds.

The Dreaded Crosswind:

A crosswind can be an asset; at least you know which way the predominant swing is going to be.

Always use the crab method on the approach and kick the drift off before touchdown. The wing down method can be used in addition to crabbing in severe crosswinds but should not be used as primary crosswind control in low wing monoplanes, biplanes or aeroplanes with toed-in wheels. Use the ailerons to keep the wings level as you ‘kick’ the drift off.
In high wing aeroplanes the wing down sideslip crosswind technique works well.
Know and practice both methods, and use the one you are most comfortable with.

The 'wheeler':

Other than the three point landing technique there is the 'wheel' landing, this is practical on aeroplanes with long undercarriages and/or full stall type landing attitudes, and is very easy to do. This technique is also better for strong/cross-wind conditions because rudder control is maintained for longer in the landing roll. To do the wheeler landing you hold off only until the aeroplane is slightly nose up from the level flight attitude, as the wheels contact the ground it is necessary to plant them firmly on the ground with forward pressure on the stick, thereafter holding the tail up until the airspeed falls sufficiently to allow the tail to gently drop. Then the stick is held back.

On some aeroplanes a trickle of power will arrest the descent rate and enable greasy smooth contact between the wheels and the ground. The wheel landing works well when there is very little sink and the wheels contact the ground gently, otherwise there can be a huge bounce.

Of course it is still necessary to kick the drift off before touch down unless the wing down technique is used.

[Some pilots prefer the wheel landing most of the time, it is so easy. The problem being that the landing roll is always longer. In some heavier tailwheel aeroplanes such as Cessna 185s you can dare to apply brakes with the tail up, but in most aeroplanes this will lead to disaster!
If the aeroplane is fitted with a STOL kit, wheeling it on is a complete waste!].

The Bounce:

Like the rudder, the elevator loses its effectiveness as the speed decays, there is a pause between input and response which gets longer as the speed reduces hence the increasing deflection of the rudder as the landing roll progresses. On aeroplanes with training wheels (nose wheels) the elevator is there for the protection of the nose wheel, on tailwheel aeroplanes it is there for bounce avoidance. Generally a bounce is caused by the mainwheels hitting the ground prematurely (1), sometimes it is caused by excessive sink rate (2, too high on the roundout), and sometimes by the nature of the ground you are landing on, (3, you picked the wrong field).

The first case can be a severe relaunch into orbit (especially with bungee U/C) in which case freeze the stick, open the throttle, and sort yourself out while going around (better luck next time).

Freezing the stick means do not move the stick forward at all, the lag between input and response is such that you will accelerate the aeroplane (when it naturally will drop its own nose), into to the ground. Let the power take effect and then fly yourself out of the situation.

If however it is a low bounce, freeze, let the nose start to drop and then continue to hold off by bringing the stick progressively back until the aeroplane is in the landing attitude. This sort of bounce is usually due to you not being patient enough during the hold off and attaining the attitude you taxied out with.

Never move the stick forward during the flare, hold off, or landing roll (unless you are wheeling the aeroplane on, or doing a touch and go). For the go around apply power first, and then move the stick.

In a heavy landing the weight of the elevator will try to deflect it downwards and the stick forwards, take control of the aeroplane and don't allow this to happen.

If you rounded out too high, you are at the mercy of the engine. Open the throttle, keep the slip ball in the middle (use the rudder) and go around.

Another form of bounce occurs during the touch and go. As you open the throttle to commence the roll ensure that good contact is maintained between the mainwheels and the ground. In other words lift the tail as power is applied, and then fly when the aeroplane is ready. If the tail is not lifted early enough, the aeroplane may get airborne prematurely then settle and start a series of bounces down the runway. Don't fight it, keep the stick in the middle, maintain heading with the rudder and let the aeroplane sort itself out. The aeroplane finds flight the most natural thing to do and often does not require a pilots’ assistance out of trouble.

PIO, Pilot Induced Oscillation is the usual result.

Finals:

A good landing is usually facilitated by a good approach.
Set the aeroplane up by trimming for the correct speed.

Most light tailwheel aeroplanes need no power on the final approach, so don't use it unless it is recommended for the aeroplane in the pilots notes. Power on and off can cause oscillations in pitch, keep a sensible attitude.* Power against flaps is like driving with the hand brake on, very inefficient, so avoid putting flaps down and then having to use power to make the field.

On some aeroplanes with poor forward visibility a stage of flap might provide a better forward view in the circuit with power on, and some mountain strips or airstrips with steep inclines may necessitate the use of power against flaps these are exceptions to the general rule.

[*In the air set the aeroplane up for a glide and note the attitudes for different flap settings. Ensure the attitude looks ‘correct-sensible’ on the approach. The airspeed indicator may be unreliable.]

The Slip:

The final thing to learn is the side slip, this involves banking the aeroplane in one direction while yawing it in the other direction causing a large increase in drag. The slip is very useful for steepening the approach, and also provides good approach visibility in aeroplanes with poor forward view (like a Pitts). It is better to learn the slip at altitude first. It is a manoeuvre which requires feel because the airspeed indicator will not be reading correctly. If the speed is too fast then the reduction of drag due to higher airspeed can nullify the desired effect. If the airspeed is too slow the resulting arrival will be dramatic, so be careful.

Flying a tailwheel aeroplane will improve your piloting ability and when you fly an aeroplane with a training wheel it will improve your landings there as well.

Typical Errors

Takeoff

Opening the throttle too quickly.

Open the throttle smoothly, look as far ahead as possible, pick an aiming point.
Like all controls, smooth application, as much as is necessary, will enable you to maintain control of your aeroplane.

The short field takeoff may require establishing full power before brake release, but then you should be ready for the swing.

Distraction.

A door opening, a pen dropped, forgetting the tailwheel lock (if fitted), are all distractions.
First and foremost maintain control of the aeroplane, ignore the distraction and either continue the takeoff or reject it.

Not lifting the tail…

The mainwheels give you traction against the sideways drift of a crosswind.
A couple of Tiger Moth accidents were when the aeroplane left the ground, slow, tail low, and drifted off the runway. The pilots tried to climb and lost control.
Make sure the aeroplane leaves the ground with enough energy for you to control its direction after lift off.

Go-NoGo Decision

Pick a point along a runway that you should reach a comfortable speed, at least 75% of your take off speed on a short strip. Be strict with this; prepared to close the throttle and stop.
If there are obstacles to climb over, “See them”, in other words lower the nose to be able to see the tops of the trees during your initial climb. In this way you should have the energy to fly over them. It is too easy to raise the nose in anxiety, not see the obstacle, and mush into it.
If you are going to crash, be in control!

A takeoff safety brief is and important way of presetting your automatic reactions:

Takeoff Safety Briefing

As you complete this takeoff safety briefing you should simulate the actions such as closing the throttle, moving the stick forward, and indicate where you will go by pointing through the windscreen.
The objective is to preset your mind and body to complete the actions automatically; this is “auto suggestion”.

• This will be a normal/short field/crosswind takeoff.

• If the engine fails on the runway I will close the throttle and stop straight ahead.
  
• If the engine fails after takeoff with sufficient runway remaining ahead I will lower the nose, close the throttle, and land straight ahead.
  
• If the engine fails after takeoff with insufficient runway remaining I will lower the nose [sixty] knots, and pick a place within [30/45] degrees of the nose.

If you know that there’s a good place to go: “In this case there’s a field just off to the right”.

The go/no go point is [pick a position] and if I do not have [75%/100%] my takeoff seed I will reject the takeoff.

After lift off, and climbing: “Power, Pressure. Temperature”

Landing

Set the glide attitude and observe the point of zero movement. This is the aiming point on the ground that is not moving ahead of you.
Adjust the point of zero movement to suit where you want to land.
Once you establish this point it will enable you to maintain your approach speed by controlling the attitude as you do with the horizon in level flight.

Be aware of windshear

If there’s significant wind, i.e. 15 knots of greater, be aware that there will be windshear, and you may need to lower the nose a little through the last 200 feet, moving the point of zero movement closer to you.
In the glide the aeroplane will lose speed quicker than it may gain speed.

Ensure the aeroplane is straight on touch down

If you learned to crab and straighten in a crosswind, this is very ‘straight forward’ so to speak!
Straighten with the rudder, keep the wings level with the ailerons, and land straight.

Try not to over control

Patience. No aeroplane will land before it is ready unless you push it on in a wheeler.
Hold off, and maintain the three point attitude. Keep straight using the rudder and ailerons.
On a warm summer’s day the aeroplane may float for longer than you are used to, stay with it, keep flying the aeroplane, and be prepared to go around if you are landing too far along the runway.

Every action requires an opposite reaction.
If the aeroplane swings, application of opposite rudder will require another correction as soon as this takes effect.
Brakes make a dramatic difference so avoid using them.

Wheel landings in low wind conditions are not recommended.

As the tail lowers you enter a no man’s land where rudder effectiveness is reducing without the replacement aid of the tailwheel/tailskid.
In a strong wind the groundspeed will be low as this happens, but in low wind conditions you have more energy for a swing to develop while you have less control authority to combat it.

Do it your way

Suggestions, such as “using peripheral vision”, are ideas that take a lot of experience.
The results are important and the way you see a landing may be different to what an expert may suggest. So observe, and land the aeroplane the way you see it.
Develop your own expertise.

The landing finishes with the aeroplane tied down, or parked in the hangar.

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