Float step placement
 

My question is the posistion of the float step in relation to the CG of the aircraft? Should the step be forward, on, or aft of the aircraft CG, and how far? Also at what angle to the aircraft center line?
Thanx for you'r help.

Jerry

Float step placement
 

The only time I ever saw the float placement stated by a recognized authority and in a numerical format, he said to put the step at 40% of the MAC, which would be slightly behind the balance point. Other sources say to put it at the balance point.

Essentially, the floats are like landing gear. Taildraggers have the wheels a bit in front of the balance point, nosedraggers (tricycle) have the wheels a bit behind the balance point.

My suggestion: Start with the balance point over the step. If you experience lateral instability on the takeoff run, cheat it back a bit. If the floats want to plow and the prop gets a lot of water, go forward a little. Just keep the floats the same.

The airplane should float with the nose up a bit, and even with the floats a bit nose-up. THe tail of the float should not be submerged.

Float step placement
 

Jim Casey

Thank you for the response, we will be trying this as soon as the weather improves.

Jerry

Float step placement
 

When setting the angle of the floats in relation to the fuselage... try to have the top level when the plane is flying straight and level at cruising speed. This is typically 2 to 7 deg down from level with the fuselage "datum" line. You are trying to minimize the drag of the floats while in flight. Look at side views of full sale floatplanes in flight. You'll see what I mean.