Taildragger Basics
General
The fact that the Center of Gravity (COG) of tricycle gear airplanes is in front of the main gear and the COG of Taildraggers is behind the main gear makes the difference in how each airplane handles while on the ground.
Taxiing
To understand why the COG position makes such a difference, picture a piece of roll on luggage, 2 wheels on the bottom and an extended handle on top. The luggage is designed to be pulled by the handle and when pulled as designed it follows along obediently because the COG, between the handle and the wheels, is in front of the wheels. If you try to push the luggage by the handle it is necessary to continually make corrections to keep it going in a straight line because the COG, still located between
the wheels and the handle, is now behind the wheels.
The concept of the roll on luggage applies to the Taildragger in that with the COG behind the main gear the airplane does not want to go straight, the COG wants to come around and go in front. It requires constant attention and corrections to keep the airplane straight. The farther out of line the tail gets the harder it is to correct until it reaches a point where it cannot be corrected resulting in a rather abrupt change of direction, sometimes referred to as a Ground Loop. Ground Loops are at best embarrassing and at worst result in damage to the airplane and possible personal injury.
When taxiing a Taildragger a good technique is to keep your feet moving at all times. Think of it as being proactive instead of reactive. If you are constantly putting small alternate inputs to each rudder pedal you can feel what is happening as it happens.
If you sit quietly and wait for something to happen you will be much slower to feel the need for a correction and much slower to make the required correction, maybe too late.
Control position while taxiing is more important in a Taildragger. As a general rule the stick (or wheel) is held in its full aft position
at all times when taxiing. The only possible exception to this rule is if there is a strong tail wind. When the wind from behind is
strong enough to cause the tail to rise, position the elevator in a neutral position (stick amidship). This will cause the elevator to
be at the same angle as the stabilizer and cause the wind to help hold down the tail. The stick should never be held forward of
the neutral position when taxiing, it should be all the way back or neutral, never forward of neutral. Rule number 1: Always keep
the stick back.
While taxiing with a crosswind the ailerons should be positioned so that the wind when blowing across them will hold down the upwind wing. If the wind is behind and to the left, the left aileron should be down causing the wind when blowing across it to push the wing down (stick right). When the wind is from the left and ahead the left aileron should be up (stick left). When taxiing in a
cross wind look at the ailerons and picture the wind moving across them and position them accordingly.
When taxiing a Taildragger you must Pay Attention from start up to shut down.
Takeoff
When taking off in a tricycle gear airplane the airplane pretty much stays straight on its own. When you reach a predetermined speed you add back pressure to the wheel (or rotate) and it flies off. Things work differently in a Taildragger. First of all you are sitting on the ground in what is at or nearly at a stall attitude so you are starting out with a force called P factor affecting the airplane almost immediately. P (propeller) factor is caused by the difference in the effective angle of attack between the ascending and descending blade of the propeller. Because the top of the propeller arc is tilted aft the oncoming air does not
strike the prop arc straight on, but at an angle. This angle causes the descending blade to have a greater angle of attack and to take a bigger “bite” of the air than the ascending blade, the descending blade is on the right (on US built airplanes) and as a
result the airplane wants to turn left with the application of power. The second force encountered at power application is Torque. The prop is spinning to the right so airplane wants to roll to the left; this is perceived in the cockpit as a turning force trying to turn the airplane left. Making this worse is the swirling prop blast which ends up contacting the vertical stab on the left side which makes the airplane want to turn left. So there are two forces trying to turn the airplane left and one force trying to roll the airplane left (feeling like a turn).
To counter these left turning forces requires the application of right rudder at the same time as power application. How much
right rudder depends on several factors; the power of the engine, the speed of the power application and the conformation of
the airplane (width of gear, length of fuselage, etc.). Only experience will show how much right rudder to add at power application for any given takeoff.
On takeoff the Taildragger should be allowed to accelerate with the tailwheel firmly on the ground until the rudder is effective enough to control the direction of the airplane. Once the rudder is effective the tail is raised a small amount to put the airplane in
a climb attitude then allowed to fly itself off in this climb attitude.
When the tail is raised, the angle of propeller arc is changed. The top of the arc goes forward reducing the angle. When the top
of the arc is forced forward by raising the tail the airplane wants to turn left. This happens because the propeller is spinning and is acting as a gyroscope, that is it is rigid in space because of its spinning speed. Gyros do not like to be disturbed when they are busy spinning, they will not turn in the direction that they are pushed. The force applied to turn a gyro will take effect 90 degrees later in the direction of rotation. The prop is turning to the right so if you push on the top of the arc by raising the tail the forward force will take effect on the right side of the arc and the airplane will want to turn left. So when you raise the tail you will need to
add more right rudder. Again how much and how quickly will depend on your forward speed and how abruptly you raise the tail. For a more controllable takeoff the tail should be raised only a small amount, smoothly and as quickly in the takeoff roll (at the slowest forward speed) allowable for positive rudder and elevator control.
Each event in the takeoff roll, power application and the raising of the tail should be anticipated by applying right rudder just as
the event takes place, do not wait until the correction is needed (be proactive, not reactive). By anticipating what correction is needed, then following up with further corrections as needed the airplane can be made to track down the runway perfectly straight. Rule Number 2: Keep it straight.
Takeoff Overview
After clearing the area for traffic taxi out and line up straight down the runway on the centerline. Let the airplane roll straight forward enough to ensure that the tailwheel is straight. Rule Number 3: Keep the stick back.
Smoothly add power in one continuous motion (a good rule of thumb is to go from idle to max power in one smooth, continuous motion that takes about 3 seconds). Lead with your right foot on the rudder pedal as you add power then make proactive rudder corrections to keep the airplane tracking straight down the runway. Rule Number 4: Keep it straight.
As the airplane gains speed the rudder gains effectiveness and your corrections will become shorter and quicker. At the slowest possible airspeed for positive rudder and elevator effectiveness begin to move the stick out of the full aft position while at the same time leading with your right foot. Raise the tail just enough to obtain a climb attitude and hold that attitude by small corrections to the stick and maintain directional control with the rudder. Look straight ahead down the runway. On some Taildraggers the forward visibility is limited or nonexistent. In that case you must use your peripheral vision while looking ahead to maintain your straight track. Looking out one side will cause you to go in that direction. Quick eye movements from side to side while keeping your main focus straight ahead will sometimes work, but you will be amazed at how quickly you will get used to using your peripheral vision while looking ahead.
A common mistake is raising the tail too high then “rotating” at a certain speed. What should happen is the airplane is put into a climb attitude and allowed to fly itself off when it is ready. You shouldn’t be looking at the airspeed indicator during the takeoff roll; it is irrelevant, your full attention should be on keeping the airplane straight. Rule Number 5: Keep it straight.
As the airplane flies off the runway you should allow it to gain airspeed as needed in ground effect. If you had the proper attitude at lift off this should be minimal. At this time, you can check your airspeed indicator and make pitch adjustments as needed. Do not chase the airspeed. These airplanes are attitude airplanes, that is you put it in the attitude for the desired phase of flight
(climb, cruise, glide, etc) then cross check your airspeed to see how close you are. After a few hours in the airplane the attitudes required will become second nature to you and you will not need the airspeed indicator.
LANDING
The normal landing in a Taildragger is a Full Stall or Three Point landing. These terms are nearly interchangeable and are descriptive of the attitude of the airplane as it touches the runway. It is fully stalled and both main tires and the tailwheel touch at the same time (sometimes the tailwheel touches first). We will discuss the other type of landing (wheel landing) later, but for now
we will stick with the normal landings. There are two primary rules when landing a Taildragger, Rule Number 6: Keep the stick
back and Rule Number 7: Keep it straight. When a Taildragger touches down it must be perfectly straight with no side drift. It must be going straight down the runway with its longitudinal axis aligned with the runway (no drift or crab). If the airplane is not aligned with the runway or not going straight when the wheels touch the sideward force will be multiplied by the moment arm that is the distance between the main gear and the COG. This could result in the COG whipping out toward the direction the airplane was drifting or crabbing and may be unrecoverable, possibly resulting in a ground loop. Rule number 8: Keep it straight.
Another consequence of the COG being behind the main gear is what happens if the mains touch before the tailwheel with more than just a very slight rate of descent. If there is a rate of descent and the mains touch the ground before the tailwheel the COG
will be accelerated downward and since the main wheels are already on the runway this results in the tail of the aircraft being accelerated downward which increases the wing angle of attack. This increase in angle of attack along with any spring in the
gear will result in the aircraft being propelled back into the air due to the increase in lift caused by the increase in angle of attack. The result will be that the aircraft bounces back into the air (the amount of altitude gained will depend on your rate of descent
and your speed at the moment of touchdown) resulting in arriving at some distance above the runway with no flying speed left. At this point a quick application of power and a go around would be prudent. The best way to prevent the above described bounce
is to have the aircraft fully stalled so that all three wheels touch at the same time. The best way to insure that all three wheels touch at the same time is to have the stick fully aft at or slightly before touchdown. Rule number 9: Keep the stick back. It is much preferable to have the airplane fully stalled and dropped onto the runway than to touch the mains first and bounce. If you must misjudge your landing height do so on the high side. Remember that when your rudder is no longer effective your only steering capability comes from the tailwheel being firmly on the ground. Rule number 10: Keep the stick back.
A good technique to help with any landing is to get the mindset that “I am not going to land”. That means that you must hold the aircraft off the ground until it stops flying and is fully stalled. If you tell yourself throughout the flare “I am going to keep this sucker from landing” you have a better chance of holding it off until it stalls. Once the airplane has settled onto the runway in a full stall attitude perfectly straight with no drift then you must continue to keep looking straight down the runway and Keep the stick back and be proactive on the rudders to Keep it straight. The landing is not over yet. You must pay attention throughout the taxi until
you have come to a full stop.
WHEEL LANDING
Wheel Landings are not a normal landing in a Taildragger but are a requirement for the tailwheel endorsement. They are fun and challenging and it is very rewarding to do one well. There are 2 types of wheel landings, the Power on Wheel Landing and the Power Off or tail low Wheel Landing.
The Power on Wheel Landing is somewhat easier to learn initially and is useful when the wind is gusty. With a gusty wind your touchdown speed should be enough above stall speed that if a gust catches you just before touchdown you will have enough speed to keep from stalling prematurely. If the wind is gusting 10 knots above the steady wind your touchdown speed should be
at least 10 knots above the stall speed. If the airplane stalls at 40 kts and the gusts are reported at 10 kts you should stabilize in slow flight just above the runway with at least 50 kts indicated airspeed.
A Power on Wheel Landing starts by establishing slow flight down the runway at a very low altitude (1 to 2 feet). Once the slow flight is stabilized start descending 1 to 2 inches at a time until the main wheels touch the runway. As the wheels touch, apply forward pressure on the stick to ensure the airplane stays on the ground and reduce the throttle to idle. The first few times this is attempted you will use up a lot of runway, that is ok and should be expected. In fact, you may not land in your first couple of attempts and a go around may be in order.
To set up for a Power on Wheel Landing, use a shallower than normal approach and feed in power a little at a time to arrive over the runway at a slow flight speed that is at least the stall speed of the airplane plus the wind gusts.
Patience, this is a maneuver that requires patience. The most common mistake is to try to land before the slow flight is stabilized. Remember, you have the entire length of the runway to land; this is not a short field maneuver. If you near the end of the runway
go around and try it again.
Once you have stabilized in slow flight just above the runway at a speed that allows for the gusts then and only then should you attempt to touch your wheels to the runway. The preferred method for touching the main wheels on the runway is; once the slow flight is stabilized, move the stick forward about an inch and move it back to its original position. This will cause the airplane to descend about an inch or two. When you are stabilized again, move the stick forward then back again. Keep doing this until the mains kiss the runway. When done properly the mains will touch with no or almost no rate of descent. As the mains touch add forward pressure on the stick to insure the wheels stay in contact with the runway, reduce the power to idle and be proactive with your left foot.
Some points to remember:
Get the mind set that you are NOT going to land. You are going to establish slow
flight just above the runway. You must have the patience to stabilize before trying
to touch down.
The first few times that you try this you will use a lot of runway. The runway use will
become less and less with practice.
If you have a rate of descent when you touch down the tail will be whipped down and a bounce will occur. It is important to descend an inch or two at a time to keep this from happening.
Add forward pressure the instant the wheels touch but do not anticipate their
touching. If you add forward pressure before the wheels touch you will bounce.
Wait; have patience, and just as the wheels touch add forward pressure.
When you reduce power to idle the nose will go right. As you reduce power lead
with your left foot (just the opposite of adding power).
Once you are on the ground you are in a most precarious position; you are rolling down the runway with your tailwheel in the air.
All you have for directional control is the rudder (and the brakes but the brakes must be used with extreme caution if at all to keep from over controlling the directional control and to keep from going over on the nose). At this point, rolling down the runway with the tail in the air your second most important consideration (the first is Rule number 11: Keep it straight) is to get the tailwheel on the ground as soon as practicable to assist in steering. You want to lower the tail as soon as possible without flying again and before it falls on its own. If the tail comes down on its own it is because the elevator becomes ineffective and will not keep the tail up and if the elevator is ineffective then chances are the rudder is also ineffective and will not provide steering. The most critical point in wheel landings is the transition from tail up to tail down. Also, when the tail comes down the nose is going to want to go right so lead with your left foot. If you control when the tail comes down you can be proactive with the left rudder. Once the tail is
on the ground the stick should be all the way back and held there, Rule number 12: Keep the stick back and pay attention until
you are tied down.
The Power Off Wheel Landing is a controversial maneuver. Some say it has no practical use, some say it will allow you to use less runway and have better forward visibility on a narrow runway while purists say that a 3 point landing is the shortest landing possible. The only thing that is undisputed is that it takes a lot of practice to master but when it is mastered provides a sense of accomplishment. The Power Off Wheel Landing starts out the same as the three point landing in that the same approach is used. The difference comes when you start to raise the nose to touch down (or flare). When doing a power off wheel landing you must delay the flare until you are closer to the runway than for a 3 point. If you start your flare for a 3 point landing at 15 feet wait until 5 feet to flare for a power off wheel landing and do not raise the nose as much. This is a feel maneuver in that you are trying to touch down with no rate of descent but before you stall. With a power off wheel landing you want to touch down with no rate of descent but still at some speed above stall and with the tailwheel still a couple of inches above the runway (almost a 3 point, but not quite).
The flare is the difference; when aiming for a power off wheel landing wait until closer to the ground to flare and don’t flare as much, that is reduce your rate of descent without losing all your airspeed. Play the flare very carefully to raise the nose just
enough to arrive at the runway with zero rate of descent and still enough airspeed to be flying. As your main wheels touch the runway add forward pressure on the stick to keep the wheels on the ground and as the airplane decelerates allow the tail wheel
to come down as soon as possible with out flying again. As in the power on wheel landing this is the critical part and should be done as soon as possible to gain the steering power of the tailwheel.
If you anticipate the wheels touching and add forward pressure to the stick before the wheels actually touch you will bounce. You must have patience and let the wheels touch before adding forward pressure.
Some points to remember:
Use a reduced flare starting closer to the ground than a 3 point.
Touch down with zero rate of descent with a speed above a stall.
Wait until the wheels touch before adding forward pressure to the stick.
When adding forward pressure you will need some right rudder.
Bring the tail down as soon as practicable.
When the tail comes down you will need some left rudder.
Conclusion
A tail dragger is different from a nose dragger only on the ground, if you can fly a nose wheel airplane you can fly a Taildragger. The difference comes on the ground and the transition from air to ground or ground to air. The differences are mainly in paying attention. You can not let your attention wander when piloting a Taildragger on the ground.
With the proper training and practice flying a Taildragger can add a sense of accomplishment and a lot of fun to your flying, and after all, if it isn’t fun why do it?