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Machinbird · 22 March 2009, 10:10 AM

Flysafe has made a very strong case that directional control is more positive and pleasant with a lockable tail wheel than with a steerable tail wheel and his observations should not be discounted.
I am still not sure I want to go that route. Why? Because I have had a brake (cable) failure in a taildragger while taxiing in close confines and what saved the day was my steerable tail wheel. With a lockable tail wheel, you are dependent on brakes for directional control at low speeds. With a steerable tail wheel, you still have options.
I have flown Cessna 170s which have steerable tail wheels and are heavier than my proposed build, a Fokker D.VII and have had no problems. Some of the problems people have had with steerable tail wheels are maintenance issues. If you look at the design of the Maule tail wheel, you will see that a properly functioning Maule tail wheel will not disconnect until it reaches 40 degrees of deflection from straight ahead. This article has information on overhaul and Rigging of the Maule tail wheel. http://www.bowersflybaby.com/tech/Maule_Tailwheel.pdf and also has important installation geometry information on tailwheels in general. If your properly rigged and maintained Maule tailwheel disconnects because of side loads, you are already in a ground loop.
The Scott tail wheel is similar in operation, but is perhaps less supportable and more complex to maintain. For such a simple looking systems, many of the interrelationships of the components are complex so it pays to fully understand them before blithely installing a tail wheel on your aircraft.
Perhaps the best solution to directional control problems on narrow (and highly crowned) paved runways is to avoid them unless everything is in your favor.
With a steerable tail wheel, if you touch the tail down with a strongly deflected rudder, you will probably get a kick from the tail wheel so you may want to ease the tail down on landing to lessen the severity of that kick. Not a big deal if you are anticipating it.

Flysafe has made a few other significant observations and we’ll see if we can add positively to them in some later discussions.
Sid

22 March 2009, 10:10 AM	#164 (permalink)
Machinbird Forum Ace Join Date: Dec 2004 Location: Chicago Area Posts: 548	Flysafe has made a very strong case that directional control is more positive and pleasant with a lockable tail wheel than with a steerable tail wheel and his observations should not be discounted. I am still not sure I want to go that route. Why? Because I have had a brake (cable) failure in a taildragger while taxiing in close confines and what saved the day was my steerable tail wheel. With a lockable tail wheel, you are dependent on brakes for directional control at low speeds. With a steerable tail wheel, you still have options. I have flown Cessna 170s which have steerable tail wheels and are heavier than my proposed build, a Fokker D.VII and have had no problems. Some of the problems people have had with steerable tail wheels are maintenance issues. If you look at the design of the Maule tail wheel, you will see that a properly functioning Maule tail wheel will not disconnect until it reaches 40 degrees of deflection from straight ahead. This article has information on overhaul and Rigging of the Maule tail wheel. http://www.bowersflybaby.com/tech/Maule_Tailwheel.pdf and also has important installation geometry information on tailwheels in general. If your properly rigged and maintained Maule tailwheel disconnects because of side loads, you are already in a ground loop. The Scott tail wheel is similar in operation, but is perhaps less supportable and more complex to maintain. For such a simple looking systems, many of the interrelationships of the components are complex so it pays to fully understand them before blithely installing a tail wheel on your aircraft. Perhaps the best solution to directional control problems on narrow (and highly crowned) paved runways is to avoid them unless everything is in your favor. With a steerable tail wheel, if you touch the tail down with a strongly deflected rudder, you will probably get a kick from the tail wheel so you may want to ease the tail down on landing to lessen the severity of that kick. Not a big deal if you are anticipating it. Flysafe has made a few other significant observations and we’ll see if we can add positively to them in some later discussions. Sid __________________ “If you want to go up, pull back on the stick, if you want to go down, pull back a little bit more.”