FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 11. Aircraft Electrical Systems | 15. Grounding and Bonding | 11-195. Static-Discharge Devices
9/8/98
AC 43.13-1B
across each hinge. In any case, not less than
two 6500 circular mil jumpers should be used
on each control surface. The installation loca
tion of these jumpers should be carefully cho
sen to provide a low-impedance shunt for
lightning current across the hinge to the struc
ture. When jumpers may be subjected to arc
ing, substantially larger wire sizes of
40,000 circular mils or a larger cross section
are required to provide protection against mul
tiple strikes. Sharp bends and loops in such
jumpers can create susceptibility to breakage
when subjected to the inductive forces created
by lightning current, and should be avoided.
b. Control Cable Lightning Protection
Bonding. To prevent damage to the control
system or injury to flight personnel due to
lightning strike, cables and levers coming from
each control surface should be protected by
one or more bonding jumpers located as close
to the control surface as possible. Metal pul
leys are considered a satisfactory ground for
control cables.
11-194. LIGHTNING PROTECTION
FOR ANTENNAS AND AIR DATA
PROBES. Antenna and air data probes that
are mounted on exterior surfaces within light
ning strike zones should be provided with a
means to safely transfer lightning currents to
the airframe, and to prevent hazardous surges
from being conducted into the airframe via
antenna cables or wire harnesses. Usually, the
antenna mounting bolts provide adequate
lightning current paths. Surge protectors built
into antennas or installed in coaxial antenna
cables or probe wire harnesses will fulfill these
requirements. Candidate designs should be
verified by simulated lightning tests in accor
dance with RTCA DO-160C, Section 23.
11-195. STATIC-DISCHARGE DEVICE.
Means should be provided to bleed accumu
lated static charges from aircraft prior to
ground personnel coming in contact with an
aircraft after landing. Normally, there is ade
quate conductivity in the tires for this, but if
not, a static ground should be applied before
personnel come into contact with the aircraft.
Fuel nozzle grounding receptacles should be
installed in accordance with the manufac
turer’s specifications. Grounding receptacles
should provide a means to eliminate the static-
induced voltage that might otherwise cause a
spark between a fuel nozzle and fuel tank ac
cess covers and inlets. In addition, static dis
charging wicks are installed on wings and tail
surfaces to discharge static changes while in
flight.
11-196. CLEANING. In order to ensure
proper ground connection conductivity, all
paint, primer, anodize coating, grease, and
other foreign material must be carefully re
moved from areas that conduct electricity. On
aluminum surfaces, apply chemical surface
treatment to the cleaned bare metal surface in
accordance with the manufacturer’s instruc
tions within 4-8 hours, depending on ambient
moisture/contaminate content.
11-197. HARDWARE ASSEMBLY. De
tails of bonding connections must be de
scribed in maintenance manuals and adhered to
carefully when connections are removed or re
placed during maintenance operations. In or
der to avoid corrosion problems and ensure
long-term integrity of the electrical connection,
hardware used for this purpose must be as de
fined in these documents or at least be
equivalent in material and surface. Installation
of fasteners used in bonded or grounded con
nections should be made in accordance with
SAE ARP-1870. Threaded fasteners must be
torqued to the level required by SAE
ARP-1928.
11-198.11-204. [RESERVED.]
Par 11-193
Page 11-81 (and 11-82)