FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 11. Aircraft Electrical Systems | 17. Connectors | 11-240. Through Bolts
9/8/98
AC 43.13-1B
separate strain relief accessory. Strain relief
clamps should not impart tension on wires
between the clamp and contact.
f. Slack. Sufficient wire length must be
provided at connectors to ensure a proper drip
loop and that there is no strain on termination
after a complete replacement of the connector
and its contacts.
compound. Preparation and storage of potting
materials should receive special attention.
Careful inspection and handling during all
stages of the connector fabrication until the
potting compound has fully cured is recom-
mended. Potting compounds selected must not
revert to liquid or become gummy or sticky
due to high humidity or contact with chemical
fluids.
g. Identification. Each connector should
have a reference identification that is legible
throughout the expected life of the aircraft.
11-236. FEED-THROUGH BULKHEAD
WIRE PROTECTION. Feed-through bush-
ing protection should be given to wire bundles
which pass through bulkheads, frames, and
other similar structure. Feed-through bushings
of hard dielectric material are satisfactory. The
use of split plastic grommets (nylon) is rec-
ommended in lieu of rubber grommets in areas
subject to fluids, since they eliminate the un-
satisfactory features of rubber grommets and
are resistant to fluids usually encountered in
aircraft.
11-237. SPECIAL PURPOSE CONNEC-
TOR. Many special-purpose connectors have
been designed for use in aircraft applications,
such as: subminiature connector, rectangular
shell connector, connectors with short body
shells, or connector of split-shell construction
used in applications where potting is required.
Make every attempt to identify the connector
part number from the maintenance manual or
actual part, and the manufacturer’s instruction
used for servicing.
11-238. POTTING COMPOUNDS. Many
types of potting compounds, both commercial
and per military specifications, are available
and offer various characteristics for different
applications. Carefully consider the charac-
teristics desired to ensure the use of the proper
a. Potting compounds meeting Specifi-
cation MIL-S-8516 are prepared in ready-to-
use tube-type dispensers and in the unmixed
state, consisting of the base compound and an
accelerator packed in paired containers. To
obtain the proper results, it is important that
the manufacturer’s instructions be closely fol-
lowed.
b. Potting compounds normally cure at
temperatures of 70 °F to 76 °F. If the mixed
compound is not used at once, the working pot
life (normally 90 minutes) can be prolonged by
storing in a deep freeze at -20 °F for a maxi-
mum of 36 hours. The time factor starts from
the instant the accelerator is added to the base
compound and includes the time expended
during the mixing and application processes.
c. Mixed compounds that are not to be
used immediately should be cooled and thawed
quickly to avoid wasting the short working
life. Chilled compounds should be thawed by
blowing compressed air over the outside of the
container. Normally the compound will be
ready for use in 5 to 10 minutes.
CAUTION: Do not use heat or blow
compressed air into the container
when restoring the compound to the
working temperature.
11-239. POTTING CONNECTORS.
Connectors that have been potted primarily of-
fer protection against concentration of
Par 11-239
Page 11-99 (and 11-96)