FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 9. Aircraft Systems and Components | 1. Inspection and Maintenance of Landing Gear | 9-9. Inspection and Repair of Floats and Skis
9/27/01
AC 43.13-1B CHG 1
9-9. INSPECTION AND REPAIR OF
FLOATS AND SKIS. Inspection of floats
and skis involves examination for damage due
to corrosion, collision with other objects, hard
landings, and other conditions that may lead to
failure. Tubular structures for such gear may
be repaired as described in the section cover-
ing welded repairs of tubular structures.
a. Floats. To maintain the float in an air-
worthy condition, periodic and frequent in-
spections should be made because of the ra-
pidity of corrosion on metal parts, particularly
when the aircraft is operated in salt water. Ex-
amine metal floats and all metal parts on
wooden or fiberglass floats for corrosion, and
take corrective action in accordance with the
procedures described in Chapter 6, Corrosion,
Inspection & Protection. Chapter 4, Metal
Structure, Welding, and Brazing, outlines
methods for repairing damage to metal floats
of aluminum and aluminum alloy structures.
Note: Blind rivets should not be used on
floats or amphibian hulls below the water
line.
In the case of wooden floats, make repairs in
accordance with general procedures outlined in
Chapter 1, Wood Structure. Repair fiberglass
floats in accordance with the manufacturer’s
instructions.
(1) If small blisters are noticed on the
paint, either inside or outside the float, the
paint should be removed and the area exam-
ined. If corrosion is found, the area should be
cleaned thoroughly, and a coat of corrosion-
inhibiting material applied. If the corrosion
penetrates the metal to an appreciable depth,
replace the metal. Special attention should be
given to brace wire fittings and water rudder-
control systems.
(2) If the hull or floats have retractable
landing gear, a retraction check should be per-
formed along with the other recommendations
mentioned for retractable landing-gear sys-
tems. Sheet-metal floats should be repaired
using approved practices; however, the seams
between sections of sheet metal should be wa-
terproofed with suitable fabric and sealing
compound. A float that has undergone hull re-
pairs should be tested by filling it with water
and allowing it to stand for at least 24 hours to
see if any leaks develop.
b. Skis and Ski Installation. Skis should
be inspected for general condition of the skis,
cables, bungees, and fuselage attachments. If
retractable skis are used, checks in accordance
with the general practices for retractable gear
should be followed. Ski manufacturers usually
furnish acceptable repair procedures. It is ad-
visable to examine ski installations frequently
to keep them maintained in airworthy condi-
tion. If shock cord is used to keep the ski run-
ner in proper trim, periodically examine to en-
sure that the cord has enough elasticity to keep
the runner in its required attitude and the cord
is not becoming loose or badly frayed. Re-
place old or weak shock cords. When other
means of restraint are provided, examine for
excessive wear and binding, and replace or re-
pair as required. Examine the points of cable
attachment, both on the ski and the aircraft
structure, for bent lugs due to excessive loads
that have been imposed while taxiing over
rugged terrain or by trying to break loose fro-
zen skis. If skis that permit attachment to the
wheels and tires are used, maintain proper tire
pressure as under-inflated tires may push off
the wheels if appreciable side loads are devel-
oped in landing or taxiing.
c. Repair of Ski Runners. Repair limits
are found in the applicable manufacturer’s
manual. Fractured wooden ski runners usually
require replacement. If a split at the rear end
of the runner does not exceed 10 percent of the
ski length, it may be repaired by attaching one
or more wooden crosspieces across the top of
Par 9-9
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