b. Main Rotor Tape Installation.
(1) Cleaning. Clean area shown in figure 3-11 with cheesecloth or machinery towel dampened with MEK,
isopropyl alcohol, or denatured alcohol.
Some rotor blades may be painted with acrylic lacquer, and MEK can adversely
affect this paint and the subsequent quality of the erosion protection. In this case,
MEK should not be used as a cleaning agent.
(2) Layout and Mask. Layout and mask off main rotor blades for polyurethane tape application as shown in figure
(3) Cut Tape. Cut tape to the dimensions in table 3-8.
Surface preparation and cleaning are the most important steps to insure proper
(4) Surface Preparation. Remove dark green paint down to light green primer in the area shown in figure 3-11
with MEK or sandpaper. Scuff the masked off area with 120 grit sandpaper. Only sand in a spanwise direction as shown
in figure 3-1, sheet 1. Use of a power polishing sander is permitted for this procedure.
Do not sand the bare metal skin of helicopter rotor blades. Sanding bare metal
skin of helicopter rotor blades reduces the structural integrity and fatigue life of
(5) Cleaning. Wipe the masked area several times with cheesecloth or machinery towel dampened with
isopropyl alcohol or denatured alcohol, then wipe with a clean, dry cloth.
Perform Steps (6) through (8) for one blade at a time.