ATA 27

Flight Control Balance And Installation
We have recently discovered several aircraft that have been repainted, and the flight control hinge bolts were painted at the same time. Makes one wonder how the facility balanced the flight controls with them installed on the aircraft.
Customers are advised to ask the selected paint shop how they balanced the flight controls. The procedures require that special tooling be used. It has been our experience that most paint shops do not have this available and just use the old "knife edge" procedure. Nothing could be more wrong, because it results in substantial weight being added to the control surfaces.
Look at the flight controls prior to accepting the aircraft after painting. We find that the floating bushings are bottomed out at the hinge fittings and the controls are not shimmed properly, allowing the control to be loose on the hinges. The elevators will fit the stab hinges either way; however, the correct way is to have the large, rectangular hinge cutout on the bottom and the tapered cutout on the top. Otherwise, interference can result between the hinge and flight control skin. Contrary to what we heard, one shop tell thier customers it is NOT the customer's choice how the elevators are installed.