FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 12. Aircraft Avionics Systems | 4. Pitot/Static System | 12-63. Troubleshooting the Pitot/Static Pressure System
AC 43.13-1B CHG 1
9/27/01
a. Before any pitot/static system is
tested, determine that the design limits of in
struments attached to it will not be exceeded
during the test. To determine this, locate and
identify all instruments attached to the system.
b. Do not clamp lines at end fittings.
c. Maintain the slope of lines toward
drains to ensure proper drainage.
b. A system diagram will help to deter
mine the location of all instruments as well as
locate a leak while observing instrument indi
cations. If a diagram is not available, instru
ments can be located by tracing physical in
stallation.
c. Be certain that no leaks exist in the
test equipment.
d. Run full range tests only if you are
thoroughly familiar with the aircraft instru
ment system and test equipment.
d. Check the lines for leaks.
12-62. RELOCATON OF PITOT TUBE. If
pitot tube relocation is necessary, perform the
relocation in accordance with the manufac
turer’s recommendations and consider the fol
lowing:
a. Freedom of aerodynamic distur-
bances caused by the aircraft.
b. Location protected from accidental
damage.
e. Make certain the pressure in the pitot
system is always equal to, or greater than, that
in the static system. A negative differential
pressure across an airspeed indicator can dam
age the instrument.
c. Alignment with the longitudinal axis
of the aircraft when in cruising flight.
12-63. TROUBLESHOOTING THE PI-
TOT/STATIC PRESSURE SYSTEM.
f. The rate of change or the pressure
applied should not exceed the design limits of
any pitot or static instruments connected to the
systems.
g. When lines are attached to or re
moved from the bulkhead feed-through fitting
or at a union, ensure the line attached to the
opposite end is not loose, twisted, or damaged
by rotation of the fitting. Such fittings nor
mally are provided with a hex flange for hold
ing the fitting.
12-61. REPLACING LINES. If necessary
to replace lines, observe the following instal
lation:
a. Attach lines at regular intervals by
means of suitable clamps.
a. If instruments are inoperative or er
ratic operation occurs, take the following ac
tion:
Table 12-1. Color codes for pitot-static systems.
CODE
ABBR. DEFINITION
COLOR
PITOT
PP
PRESSURE NATURAL
STATIC
PRESSURE
SP
(PILOT)
RED
STATIC
PRESSURE
GREEN
(CO-PILOT)
STATIC
PRESSURE YELLOW
(CABIN)
STATIC
PRESSURE
(STANDBY)
BLUE
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