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ETLB Squawk Forums  /  Flying Stories  /  First paved runway landing
Posted by: BlueMax, October 3, 2008, 4:03am
I acomplished another first tonight, I made my first landing on a paved runway! My plane handled the touchdown and rollout quite well, But at 10mph+ the tail wheel seemed to "chatter" and rotate from side to side stretching the springs and making 90deg turns at random. I had no problem maintaining direction control when this was occuring it just shook the pland in a most unpleasant way! On the takeoff roll I held the stik full foward in order to raise the tail as soon as possable. Any idea what would cause this?

Here are some pics of the nights flying.
Chris

Grain elevator


taking off from cook field

Posted by: Charlie Harris, October 3, 2008, 6:16pm; Reply: 1
Criss the pics. are great, what camara are you useing, also if You just came off that paved runway, whyat kind of climb rate would you think?  Charlie
Posted by: CFBTB, October 3, 2008, 10:45pm; Reply: 2
Your tail wheeel is very out of balance and the initial vibration brought on a dynamic condition much like fluttter. Static balance the tail wheel.
Posted by: 706 (Guest), October 3, 2008, 11:28pm; Reply: 3
Chris,
In the legal Eagle plans set Mr. Mulholland says to set a 2 degree positive caster in the wheel to help avoid shimmy. Also something that has helped me over the years with Maule tailwheels, which will shimmy mightly at low speeds, are the anti-shimmy springs. They are two different sizes ,the lighter spring goes on the left size. The wheel and spring has a natural frequency and begins to viabrate when this frequency is reached, usually at slow speeds as the plane is slowing down. If you have the new Spruce catalog they are on page 250, and page 385 in the new Wicks catalog. Also tightning the bearings a bit more can change the frequency of the viabration.
Tom Mathes
Posted by: 706 (Guest), October 3, 2008, 11:43pm; Reply: 4
Chris, forgot to mention this in the last post. The paved runways have a crown in the center so it will drain. Sometimes my Champ would start the shimmy if i landed and rolled out on the CL. The wheel would ride first one side of the crown and then the other and that started movement. The center of the runway is supposed to very round on the transition but some are not and are sharp there. I started landing with the tailwheel on one side of the crown and as long as i didnt go over and start turning at low speeds i didnt have much problem then. Doing what you did by lessning the down force by backing off the up elevator some if it starts will help.
Tom
Posted by: BlueMax, October 6, 2008, 9:15pm; Reply: 5
Thanks for the comments guys, I will ballance the TW and go from there.
Charlie,
My climb rate is a quite impressive 1100ft a minute af max power 3750rpm. I normaly throttle back to around 3k after getting above the trees giving me a climb rate of about 700fpm. To take that photo I got the plane off the ground in about 40ft and throttled back to about 2650, giving me a shallow climb and ensuring that I would not be too high for a pic as I crossed the end of the runway.
I am using a 8 megapixel Olympus stylus 850SW, It does a good job but I still have to take a boat load of pics to get a good one.

Happy Flying
Chris
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