Beyond the PPL: time for taildragging
- Credit: Archant
One way to improve your flying skills after gaining a PPL is to learn how to fly tailwheel aircraft — so what’s involved, and what makes them so difficult?
You would have to go back at least fifty years to find a time when most pilots were taught on taildraggers. Today nearly everyone learns in an aeroplane with a nosewheel, and for good reason. Having the third wheel at the front gives better stability on the ground and simplifies landings and takeoffs so that you master flying more quickly.
However, there are disadvantages. A noseleg adds drag and weight and is vulnerable to damage. It’s expensive to make one with a good shock absorber and an effective steering link, and they can be costly to maintain. Having a nosewheel can be a real problem on grass runways, particularly if they’re short and muddy. The nosewheel digs in, and when the straining engine and propeller finally get enough airflow over the elevator to lift the nosewheel out of the mud, the wing will be at a high angle of attack, adding drag. That can keep you grounded long after a taildragger will have lifted off and be climbing away. It may even keep you grounded all the way to the far hedge.
You can’t teach yourself to fly a twin, autogyro or turboprop, because ratings are mandatory for all three. Most people think a tailwheel rating is mandatory too, but actually you can teach yourself and I don’t think it would be entirely reckless if you were cautious and had the right kind of aeroplane, such as a two-seat Jodel, 90hp Super Cub or Evans VP-1. All of these are modestly powered with long fuselages and short propellers, allowing a shallow ground angle and a stubby nose you can see over, even with the tail down.
Some are easier than others
However, there are hazards to taildragging, even with these more easily tamed examples of the breed, let alone notoriously difficult taildraggers like the short-coupled Piper Pacer or wildly overpowered P-51 Mustang (a friend serving in Korea saw one of those groundloop on take off, flip over and burn). What are these hazards?
Guard that prop!
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A nosewheel keeps the propeller from contacting the ground, but in a taildragger you get no such protection. It’s usual at start up to have the stick held back, since some taildraggers (not many, actually) can go over on their nose if the stick’s centred when the engine’s running. You also have to think a little more when taxying, since an over-enthusiastic stamp on the toe brakes can put some taildraggers on their nose. Keep a good lookout, but above all, taxi slowly?there might be a hidden rabbit hole for one wheel to drop into. The other thing you need to think about when taxying is what might be happening in front of you, since with the tail down in many taildraggers, all you can see ahead is the engine cowling. The answer is not to taxi in a straight line, but in a series of gentle turns.
C of G working against you
One of the main in-built problems with taildraggers is their instability as ground vehicles. In a nosewheel aeroplane the centre of gravity is ahead of the main wheels (if it weren’t, the fuselage would fall back on its tail). This means that the aeroplane’s weight tends to correct any turning tendency. In a taildragger, the weight is behind the mainwheels and makes any tendency to swerve worse. The faster the turn, the more a taildragger’s configuration accelerates it. If the pilot doesn’t react in time, the momentum of the rear end reaches a point where even full opposite rudder and brake can’t stop it. This is the dreaded groundloop, a bit like a puppy chasing its tail, and just like the puppy, the taildragger generally ends up falling over sideways, comically if you don’t happen to be in the cockpit. The risk of groundlooping and dragging a wing is why so many Great War taildraggers had hoops under the wingtips.
A big change of attitude
Taildraggers have attitude problems. In a nosewheel aeroplane you learn to unload the nosewheel at the start of the takeoff run; that’s to say, you ease back on the yoke. In a taildragger you do the opposite, pushing the stick forwards to lift the back of the aeroplane. If the undercarriage is stalky, this can mean a substantial change of attitude. On the one hand, this comes as a considerable relief, because you can now see ahead. On the other, given the directional instability described earlier and the gyroscopic effect of raising the tail, you might shoot off to one side before you’re even aware of what’s happening. The answer is to be ready with your feet and correct any yaw the moment the tail’s up. In a Lycoming-engined aeroplane, you’ll need some right rudder. If it’s a Pitts Special, quite a lot of right rudder – maybe half. And if it’s a P-51 Mustang and some other over-powered types, even full pedal won’t be enough at maximum throttle, so you must advance the power lever by degrees until there’s enough airflow over the rudder.
When landing, the aeroplane’s attitude ought not to be a problem. After all, in both nosewheel aeroplane and taildragger the requirement is the same: to skim over the runway with the throttle closed, the nose coming up. The touch-down, when it comes eventually, should be with the fuselage tilted up. In a nosewheel aeroplane, you then gently lower the nosewheel as the speed falls. In a taildragger, assuming you’ve done everything right, the wheel at the back arrives with the mainwheels, so it ought to be even simpler: no nosewheel to lower.
Well, no. Firstly, you’ll be lucky to touch down on all three wheels at the same time. If the rear wheel touches first, the aircraft will pivot on it and come down heavily on the mains. If the rear wheel doesn’t touch, the aircraft will quite probably start bouncing. Secondly, you’re back with the problem you had at the start of the takeoff run, of not being able to see over the nose... only this time you’ll be going much faster. For most beginners, though, it’s the bouncing that causes the biggest problem, so we’ll tackle that next.
All aircraft bounce if you touch down too fast. The secret is to keep the aeroplane skimming over the runway with the throttle closed until it has lost all its energy and only then allow the wheels to touch. There are several reasons why taildraggers are more likely to suffer in this way. Firstly, the weight being centred behind the main wheels means that when they touch, the tail comes down, just as if you had pulled back on the stick. Secondly, many taildraggers have rather basic suspension without any damping. The impact force of the wheels hitting the ground is retained and pushes the aeroplane back up. Bungee loops, which are used in the J3 Cub and many Pitts Specials, stretch when the wheels hit, then compress with almost equal force. The cantilever undercarriage fitted to Champs and Citabrias can also spring back to launch you back into the air. The rubberin-compression arrangement employed in Jodels and Stampes tends to be more forgiving. Best of all is oleo suspension, which absorbs almost all the energy and gives a soft landing even if you do touch down prematurely.
If you do bounce, and it’s not too violent, it’s probably best to sit out the subsequent impacts with throttle closed, stick an inch back from centre and concentrate on keeping straight. If you’re in a Pitts Special, this kind of arrival is normal and you can take comfort that it feels a lot worse than it looks; any spectators probably won’t notice. However, if the second bounce is worse than the first, you must open the throttle and go around. The best response to a bad bounce is to hold off until the aeroplane has lost energy and only then allow the wheels to touch.
Some taildraggers have an additional problem: the tailwheel is too close to the mainwheels. Piper Pacers and Pitts Specials have this and it leads to ‘bucketing’?alternate bouncing off the mainwheels and tailwheel. The longer the fuselage, generally speaking, the easier the taildragger is to land, not least because it gives a flatter ground angle.
Wheeling it on
Instead of a three-point landing (one on all three wheels simultaneously) the taildragger pilot has the option of touching down in a level attitude on just the mainwheels. Some vintage types must, in fact, be landed this way because the rudder is blanked by the fuselage once the tail comes down. Even relatively tame taildraggers like the Tiger Moth and Stampe are easier to control in a crosswind if they are ‘wheeled on’. When you touch down on the mainwheels, the tendency for the tail to drop because of the C of G position must be checked with some forward stick. The timing is crucial because if you are slow to react, you will have bounced and be airborne when you give the forward stick, leading to a second, bigger bounce. It’s possible to set up a rhythm of being just too late every time the wheels touch. However, it’s worth persevering with learning to wheel your taildragger on, because it can be useful in crosswinds and when it’s absolutely vital to be able to see over the nose (e.g. if there are sheep in the field).
In a mainwheel landing or ‘wheeler’, once the wheels are on the ground you keep the tail up by gradually advancing the stick. By the time the stick hits the forward stop, the aeroplane will have slowed to walking pace. The tail will come down gently by itself. This stickprogressively-forwards technique is the opposite of what you do in a three-point landing. In a three-pointer, keep the stick back and the tailwheel firmly grounded, as it’s the most reliable way of steering and preventing a groundloop. And as a taildragger pilot, one thing you should definitely be aware of is how?and if?the tailwheel is steered, because some are just left free to castor.
Most taildraggers have a wheel at the back that’s linked to the rudder with springs and a short length of adjustable (you remove or add links) light chain. Usually the chain is left a little loose in order to have roughly the same gearing for rudder and tailwheel steering. A tight chain gives a smaller turning circle for taxying, but can make the aeroplane skittish on landing. Taildraggers that are ‘squirrely’ in this way can have the mainwheels mis-aligned; usually with toe-in. Toe-in can turn a usually mild-mannered taildragger like a Condor or Jodel into a groundlooping monster. The tailwheel is much smaller than a nosewheel so it’s less effective, which is another reason why taildragger handling is more difficult.
Most modern tailwheels have an internal spring and a cam that holds them centred. The spring can be overcome by braking on one side for turning. This self-centring arrangement helps avoid groundloops. Some high-performance taildraggers have a lever for locking the tailwheel which must be set before takeoff or landing. Another arrangement, found in the Stampe, is a fully-castoring tailwheel. The Stampe, Chipmunk and Turbulent?among others?have differential brakes on the mainwheels; in the Stampe the combination of differential brakes and a castoring tailwheel produces much the same effect as a steerable tailwheel. Instead of being worked independently by pedals or a lever?parking lever aside?the brakes in these taildraggers are applied progressively as you approach full rudder.
Starting on the right surface
When learning to fly taildraggers, begin on a grass runway and only move on to concrete or tarmac later. Grass gives better control and reduces the likelihood of a groundloop. It almost goes without saying that crosswinds and wet surfaces are also conditions to be avoided at first.
Lower crosswind limits
Taildragger techniques for coping with crosswinds are the same as with nosewheel aeroplanes: yaw or sideslip into wind during the approach, correcting before touchdown; begin the takeoff run with into-wind aileron; and beware the weathercocking effect. Most taildraggers, though, have a low crosswind limit because they don’t steer as well as nosewheel aeroplanes.
Some taildraggers have fore-and-aft seating, which at first sight seems to make things even more difficult. In a J3 Cub, Tiger Moth, Extra, Pitts S2 or Stampe you solo from the rear seat half-way down the fuselage with an awful lot of aeroplane between you and the view ahead. If you’re carrying a passenger, just about all you can see is their head and shoulders. However, most pilots get used to this quite quickly and learn to manage with a peripheral view off to both sides. They also discover a compensating factor: the further back you sit, the easier it is to sense an impending groundloop. Sitting half-way down the fuselage is also better for aerobatics, and helps you to judge attitude for wheeling the aircraft on and the right moment for checking forward with the stick. In short, if you fly ‘by the seat of your pants’?by feel rather than by numbers?the rear seat in a fore-and-aft cockpit will seem quite natural and you’ll hate reverting to sitting next to people just behind the propeller.
Side-by-side seating does have one disadvantage: being offset to the side makes it more difficult to land accurately. In theory, arriving yawed ought to cause problems in Jodels and other side-by-side taildraggers, but in practice it seems to make little difference.
Getting the heft of it
You might like to raise the tail by hand; something you can only do if there’s no nosewheel. Get a firm grip on the leafsprings supporting the tailwheel and lift. As you raise the back of the taildragger you will feel it get lighter until at some point, were you to let go, the aeroplane would fall on its nose. Some taildraggers? the Skybolt is one?have the mainwheels set well forwards. This means the tail has to be very high before the aeroplane goes on its nose. Others, such as the Turbulent, have the mainwheels set aft. The rearward setting enables you to raise the tail more quickly for taking off, giving a shorter takeoff run, and also puts less weight on the leafsprings supporting the tailwheel, so that they last longer. However, it also makes it much easier to put the aeroplane on its nose. Taxi a Turbulent with great care, because a gust can lift the tail... and be ready to snap down the mag switches if it does. Many a Turb prop has been saved by quick action. Most authorities advise taxying with the elevator at neutral when the wind is coming from behind.
That skid is a brake
The Tiger Moth has a tailskid that steers (it’s linked to the rudder). A few Turbulents have a tailskid, as do some Currie Wots and a few other aeroplanes. There’s usually a shoe on the end, which wears down and needs periodic replacement, frequently if you fly from concrete or tarmac. The main thing about tailskids is that they are terrific anchors on soft ground, but quite useless for slowing you down when the ground hardens, substantially lengthening the landing run. Another thing you need to know is that, aside from the Tiger Moth, once the ground is soft you should do as little steering as possible with the skid grounded. The mounting of a fixed skid will suffer a lot of strain if you make turns with the skid buried and dragging sideways. The proper technique is to give a blast of throttle with the stick fully forwards, using rudder to turn the instant the skid leaves the ground. This works surprisingly well, unless you’re going downhill and have no brakes. It’s important to plan ahead when taxying any taildragger, but particularly one with a fixed tailskid.
Getting some instruction
No club will hire you their taildragger?or any nosewheel aeroplane for that matter? without at least a check-out. Perhaps one in five clubs around the UK have, or have access to, a taildragger and at least one instructor able to teach tailwheel. It’s not unusual for clubs to lease a taildragger from a private owner. An alternative route into taildragging is to buy a share in one that’s group operated, in which case the other owners will certainly insist that you are checked out, probably by an instructor.
You can buy a taildragger and find an instructor willing to instruct you in it – there are plenty who will come to you. A lot of recently qualified PPLs get a tailwheel rating just to improve their flying skills and go on to fly nosewheel aeroplanes. Around a quarter of flying schools list tailwheel ratings as one of their courses, and there are some specialist schools like the one at Clacton, which instructs on Super Cubs, and Cambridge, which uses Tiger Moths. There is also tailwheel instruction on offer at the Tiger Club at Headcorn. See Pilot’s Where to Fly Guide to identify others.
If you don’t intend flying a highperformance aerobatic taildragger, you will be making things unnecessarily difficult learning tailwheel on one. The same is true for learning on a vintage aeroplane like the Tiger Moth. How quickly you master taildraggers depends on your existing skills. As a newly-qualified PPL, I had three dual circuits in a Condor, then bought an Evans VP-1, which was a lot easier to fly than the Condor. I then went on to a Turbulent and Jodel, neither of which gave me any trouble. However, I then joined the Tiger Club and had enormous difficulty mastering the Tiger Moth, only just succeeding in soloing it within the five-hour maximum then allowed. (If you didn’t solo within five hours you were out.) Subsequent taildraggers, including the Extra 300, Pitts S-2C, Laser and Miles Gemini twin I took in my stride, the lessons taught by the Tiger Moth having pretty much prepared me for anything. And there was one aerobatics contest when several Pitts Special pilots retired because of a strong crosswind. I carried on in my Stampe. It had to be helped onto the runway by wing walkers and I needed assistance to taxi after landing, but we coped.
Whichever route you take, have fun taildragging!