manufacturer by code markings which are repeatedly
stenciled along the full length of the hose.
(1) Markings. The identification markings will
either be manufacturers code number or manufacturers
symbol, also date of manufacture in quarter year and
year, size of hose, and specification of hose in numerals
(figures 4-34 through 4-38).
(2) Stripe. The indicator stripe or code symbol
along length of hose shall, in all cases, identify hose
(2) Store hose or hose assemblies on racks
which support and protect hose and hose assemblies.
(3) Store hose or hose assemblies so that older
items are used first.
Replacement of Flexible Hose. Inspection and
replacement of hose or hose assemblies will be accom-
plished at inspection periods perscribed in applicable
aircraft maintenance manual or whenever defects listed
below are evident.
(3) Temperature range. The indicator stripe indi-
cates that hose is suitable for use through a temperature
range of -65 to 160°F (-54 to 71 ºC).
(4) Hose. MIL-H-8788. This hose will appear in
(a) Markings. Hose in each assembly will be
marked with quarter year and year of manufacture of
hose, hose size, specification number, and an indicator
stripe in the form of a yellow dot and dash code, showing
direction of natural lay of hose. Markings are repeated at
intervals of not more than 9 inches along length of hose.
(b) Identification tag. This hose is also iden-
tified by a removable metal tag or band, installed at the
factory when hose is assembled, showing part number
of hose assembly, date of assembly, and name or trade-
mark of manufacturer.
Storage of Hose and Hose Assemblies. Hose or
hose assemblies shall be stored as follows:
Do not store hose or hose assemblies in piles.
(c) Inspection. Rubber products should be
To do so will result in decreased strength and
carefully inspected prior to installation and during use for
(1) Seal both ends of bulk hose. Cap or plug
each hose or hose assembly as outlined in paragraph
(d) Replacement. Replace hose or hose as-
semblies with weather checking that is deep or wide
enough to expose fabric.
(7) Deterioration. Replace all hose and hose
assemblies showing signs of deterioration indicated by
separation of rubber cover or braid from inner tube,
cracks, hardening and lack of flexibility.
(2) Cold Flow. Replace hose or hose assem-
blies showing signs of excessive cold flow indicated by
deep permanent impressions and cracks in hose or cov-
er produced by pressure of hose clamps and head of
(3) Weather checking. Weather checking of rub-
ber is caused by sunlight and atmospheric oxidization.
(a) Early stages. Rubber hoses, tubing or
rubber outer coated surfaces will show fine line cracks or
crazing but will be pliable when squeezed between the
fingers or rolled between the hands. This is a sign of the
early stages of deterioration.
(b) Advanced deterioration. As deteriora-
tion continues, the cracks and crazing become more
prominent, and when the rubber hose or tubing is
squeezed or rolled, the item will break, shatter, or turn to
powder, thus becoming useless.