HOLE TO BE
Figure 3. Template Placed on Helmet.
When the helmet shell is drilled in step (k), the drill bit may penetrate the
shell very quickly. To avoid injury, keep hands away from the inside of the
When performing step (k), hold the drill perpendicular to the helmet shell
to prevent damage to the shell and the energy-absorbing liner. Ensure that
the earcup, the wires, and the retention assembly inside the helmet shell
are away from the area where the hole is to be drilled to prevent damage.
If the helmet shell is not drilled in the following manner, delamination of
the shell layers could occur, making the helmet shell unserviceable.
(I) Drill a 1/8-inch hole into the marked location.
(m) Drill a 1/4-inch hole into the 1/8-inch hole.
(n) Drill a 3/8-inch hole into the 1/4-inch hole.
a razor knife
to remove any frayed helmet fibers resulting from drilling.