Tail Assembly Balancing the Controls

From "Construction Notes" Falco Builders Letter, June 1993

We've had some questions on the technique used for balancing the controls. If you're like most homebuilders, you'll get a lot of free advice from people who don't know what they're talking about, and there's more bad advice floating around about balancing controls than almost anything else.

The balancing of the controls is something that's done as a flutter consideration. There are other factors as well, principally the control cable tension and the harmonic frequencies of the airplane. To be correctly 'balanced' according to the specifications, the center of gravity of the control surface is aft of the hinge line, thus the controls are all 'tail heavy' by the amount specified.

From "Construction Notes" Falco Builders Letter, September 1993

Garry Wilburn asks when is the right time to balance the controls and to make the measurement. He assumes the weights as specified are in the final finished form, but might it not be instructive to make a preliminary balance test to see how things are coming ou?. Typically builders weigh things before painting and then there is a final weighing before the first flight. The final weighing is mandatory, of course.

From "Construction Notes" Falco Builders Letter, March/June 2002

Tim Painter asks, "As I started so long ago, I have fabric-covered control surfaces. The ailerons and flaps come out at 14 oz, two oz. under, and the rudder at 26 oz, including the tail light. However, the elevator is way over-balanced. I have removed 6 oz from the mass balance to achieve minimum weight (33 oz). This includes the trim tab and operating cable coiled to cancel any bias. Have I missed something or is English lead heavier than American?"

I suspect it's just a matter of fabric covering and that type of construction being much lighter.