This is a problem with all tail dragger type aircraft. (especially full scale) When the tail wheel leaves the ground, the nose of the airplane goes down. This causes gyroscopic precession on the propeller, thus causing the airplane th yaw to the left since the force applied to a gyroscope is realized exactly 90 degrees clockwise to the force. Ex. The top of the prop is pushed foreward, so 90 degrees clockwise puts that force right at the 3 o' clock position. This causes the airplane to yaw to the left. When the bottom of the prop is pushed back, exactly 90 degrees clockwise puts the force at the 9 o' clock position, pushing backwards on the prop causing the airplane to yaw to the left.

Here's a pic so you can better understand this concept:
http://www.free-online-private-pilot...ising-tail.gif

Another force in action here is called p-factor. This is when the rotation of the plane momentarily causes the descending propeller blade to produce more thrust than the ascending blade, causing the airplane to roll to the left. This force is less apparent on small r/c craft than it is on full scale craft. You can experiment with p-factor by flying straight and level, and throwing the stick forward very hard. Don't let go. (mind you, you must have enough altitude to recover from a steep dive before performing this procedure) A well designed craft with a small prop will barely be affected, while a light weight craft with a large, slow flyer prop will be adversely affected.

My advise is to move the throttle stick to about half throttle, and let the plane gain some speed. Push the right stick forward and bring the tail up. Then add full power while releasing the right stick. Once your plane has gained enough airspeed, it will lift off the deck on it's own.

Do not fly like this in bumpy grass, as you are likely to bring the tail up, and the prop will smack the ground since the plane is bumping all over the place. Only fly like this on a smooth flat runway.



It IS Rocket Science!