Taildragger handling

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Taildragger handling

Post by Greg Russell-Brown on Mon Nov 21, 2016 8:27 am

Aircraft fitted with what is known as a (tricycle) undercarriage are much easier to handle when taxiing and during the takeoff roll.

Tail draggers however, (aircraft with no nose wheel but a small tail wheel instead) can prove to be much more difficult to handle especially in a crosswind.

There are various factors to take into consideration when using this kind of undercarriage system.

The three main considerations are:
1: The effect of crosswind on the aircraft
2: The torque of the engine and propeller
3: The main undercarriage location with respect to the aircrafts centre of gravity (C of G) If the C of G is very close to the main undercarriage this means less of the aircraft's weight is on the tail wheel and results in minimal traction, this of course reduces the authority of the tail wheel.

When taxiing it is beneficial to use at least 15 degrees of up elevator as the effect of prop wash (airflow over the aircraft produced by the propeller) over the tailplane with up elevator applied deflects the tail downwards thus applying more pressure on the tail wheel and therefore more traction.

When beginning the takeoff roll the primary consideration is the crosswind component (if present) as once the aircraft starts its roll the tailplane will lift and weathercock into the crosswind.

The way to negate this effect is to apply a moderate amount of rudder input opposite to the crosswind as the takeoff roll is commenced and then gradually release this rudder input as the aircrafts' airspeed increases.

The aircrafts' tracking on the runway once it has passed a critical speed before which the crosswind would more easily weathercock it into wind is then held in check by carefull and quick response with the rudder input as appropriate to maintain a straight track down the runway.

(the critical speed referred to is a result of more forward speed which vastly increases airflow over the aircraft thus increasing rudder authority and almost completely overcomes the effect of a crosswind).

Like all things this takes practice to perfect and the amount of rudder used is of course dependant on its authority and this varies with factors such as:
1: The size (surface area) of the rudder
2: The type of airfoil cross section of the vertical stabilizer including the rudder
3: Propwash effect and quantity
4: Engine torque
5: Moment arm (how far the rudder is placed physically away from the centre of gravity of the aircraft)
6: Crosswind component speed
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Greg Russell-Brown
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