Welding and brazing should not be
considered critical. However, welds
should be reasonable smooth and free
of craters and other irregularities
which would indicate an unskilled or
f. Flanges and Closure Fastener Surfaces. Straighten steel flanges which are bent or otherwise deformed, by heat-
forming and hammering. Straighten closure fastener mounting surfaces on main rotor blade box by cold-forming.
Visually check for cracks in repaired areas. No cracks allowed.
g. Sanding. Prior to leak test, clean and sand all areas which were burned during heating or welding. in lieu of
sanding, corrosion removing compound may be applied as indicated in paragraphs 3-2a(1) through 3-2a(3).
h. Leak Test. Before refinishing, test container for leakage as indicated in paragraph 2-3k. Eliminate leaks which are
disclosed, by welding. Areas that reveal leaks which are inaccessible to weld repair may be repaired with sealing
compound conforming to MIL-S-8802, Class B-1/2. Apply compound to interior of defective area in container by using an
extrusion gun, spatula, putty knife or other suitable means. Compound should be approximately one-sixteenth of an inch
thick after application. After sealing compound has cured, repeat test.
i. Distortion. Correct distortion of main rotor blade box to insure proper installation of rotor blade and ease in closure
and stacking of box. Top, sides, ends and bottom must present an overall true plane.
j. Rips and Tears. Replace ripped or torn panels in main rotor blade box which cannot be repaired by welding or
patching. Use aluminum sheet of like alloy and thickness.
k. Bumpers. Install bumpers on main rotor blade box that has been