(SRM) provides the approved repair procedures for all
levels of maintenance. Information contained in the
SRM includes damage classifications, inspection
procedures, typical repair procedures, and tool and
material lists. Damage exceeding any of these
classifications require engineering disposition. The
examples listed below may vary somewhat, depending
upon the type of aircraft and the specific location of the
damage on the aircraft.
Cuts, scratches, pits, erosion or abra-
sions not exceeding 0.005 inch in depth
and 5 inches in length.
Damage with dents in the skin up to 3
inches in diameter and 0.01 inch in
depth, with no delamination between
skin plies, no cracks or graphite fiber
breakage, or skin to honeycomb core
Delaminations between plies, including
Figure 5-25.--Example of negligible damage on composite
the skin land area, opened up to external
edge and up to 1 1/2 inches in diameter.
the degree of urgency, and any other circumstances
Skin damage including delaminations,
impacting the situation.
cracks, cuts, scratches or skin erosion
exceeding 0.015 inch in depth, but less
than full penetration, with no damage to
Negligible damage is damage that can be permitted
to exist "as is," or corrected by a single cosmetic
refinishing procedure with no restrictions on flight
operations. This damage may also include some
delaminations, disbonds, and voids. See figure 5-25.
Nonrepairable damage exceeds published criteria
or limits. Nonrepairable damage may be reclassified as
repairable, if cognizant engineering authority
prescribes a repair on an individual basis. Normally,
nonrepairable damage requires the changing of
Repairable damage is any damage to the skin,
bond, or core that cannot be allowed to exist "as is"
without placing performance restrictions on the
aircraft. All permanent repairs must be structural,
restore load-carrying capabilities, meet aerodynamic
smoothness requirements, and meet the environmental
durability requirements of the aircraft. See figure 5-26.
Repairable damage is divided into several
classifications. The aircraft's structural repair manual
Figure 5-26.--Example of repairable damage on composite