SCRAPTo discard, with proper authori-
zation, items, parts or materials that are obsolete
or no longer usable.
SDLMStandard depot-level maintenance.
Provides for a comprehensive inspection of
selected aircraft structures and materials, critical
defect correction, preventive maintenance as
required, modification and technical directive
compliance to ensure reliability and operational
availability of the aircraft at minimum cost for
the established operating service period, and to
provide intermediate support during the total
level rework concurrent with special rework, the
accomplishment of which alters the basic charac-
teristics of the aircraft to such an extent as to
effect a change in any part of the model
designation (i.e., F-4B to F-4D). NAVAIR
SDLM/CRASH DAMAGEIn addition to
accomplishing SDLM (standard depot-level main-
tenance), repair and restoration to a serviceable
condition that part of the aircraft that has
sustained damage resulting from an accident or
of standard depot-level rework concurrent with
a modification that causes major work effort
resulting from the installation of these technical
directives. NAVAIR approval required.
SEAMA series of stitches joining two or
more pieces of cloth. For government work, the
type of seam is indicated by a symbol that gives
the class of seam, the number of stitching, and
the number of rows of stitching. (Reference Fed.
SEAM, DIAGONALA French-fell seam of
the canopy that joins two sections of a gore.
Diagonal seams meet the centerline of the gore
at angles of 450 and 135.
SEAM, ENGLISH-FELLA seam in which
one piece of cloth is folded back upon itself, and
the other piece is a plain overlap.
SEAM, FOUR-NEEDLE FOUR-STITCH
A method of stitching that can be performed in
one operation by a four-needle sewing machine.
It is used in sewing the vent hem, skirt hem, and
radial seams of a canopy.
SEAM, FRENCH-FELLA seam in which
the cloth is folded back upon itself and stitched.
SEAM, OVERLAPA seam in which the
two pieces of cloth are joined by overlapping
enough to accommodate one or more rows of
SEAM, RADIALA seam, joining two
gores, that extends radially from the vent to the
SEAM, TWO-NEEDLE TWO-STITCHA
seam in one operation by a two-needle sewing
machine; for example, a diagonal seam.
SEARTo melt or seal with heat; for
example, to sear the end of nylon webbing, one
heats the end until the nylon melts and
fuses. This prevents raveling. Also, the catch
that holds the hammer of a firing mechanism
cocked. The sear in an automatic parachute
ripcord release is attached to the aneroid in the
SEAT PANA sponge-rubber-covered metal
seat that is contoured for comfort to the user. A
seat pan is used with seat-type parachutes and
back-type parachutes when a packaged life raft
assembly is used. A high-speed seat pan has
sections for support under the pilots thighs during
ejection. This reduces leg strain caused by high
SECTIONEach major part of a gore.
Sections are bordered by radial seams, diagonal
seams, or vent or skirt hems. In the 28-foot, flat
canopy, four sections are used in each gore
(previously known as panel).
SECURITYAn item firmly, positively,
and safely attached in the authorized manner.
SELVAGEAn edge of a woven fabric so
formed as to prevent raveling, as compared to a
cut edge, which will ravel.
SELVAGE, BROKENCut, broken, or tom
SELVAGE, STRINGY OR LOOPYIr-
regular stringy or loopy selvage edge.