CESSNA®
MODEL 525B
MAINTENANCE MANUAL
3.
Safety Precautions and Preparations
CAUTION:
Apply maintenance warning tags and signs as appropriate. Set the PITOT
STATIC HEAT 1 and PITOT STATIC HEAT 2 switches to the OFF position
during the test. Damage to components and/or equipment can result.
CAUTION:
Do not let the static system pressure exceed the pitot system pressure,
as instrument damage can result. Do not apply pitot pressure to the static
system or vacuum to the pitot system. Do not use soap and water, or any
liquid, to do a leak test of the pitot and static system.
CAUTION:
Do not cross-connect the tester to the airplane system. For example, do not
cross-connect the pitot input to the pilot system and static input to the copilot
system or the pitot input to the copilot system and static input to the pilot
system. Do not disconnect any lines or equipment while test pressures are
applied. Damage to the system can result.
A.
Safety Procedures.
(1)
Make sure that the PITOT STATIC HEAT 1 and PITOT STATIC HEAT 2 switches found on the
right switch panel are in the OFF position.
(2)
Use a single pitot-static test unit, connected to the pitot and static tubes, to constantly monitor
the airspeed.
NOTE:
Each static tube stops at three static port outlets, which are on the left and right side
of the forward lower fuselage.
(3)
Do not cross-connect the tester to the airplane systems (for example, the pitot input to the pilot
system and the static input to the copilot system or opposite).
(4)
Do not apply pitot pressure to the static system. Use vacuum only.
(5)
Do not apply vacuum to the pitot system. Use pressure only.
(6)
Do not disconnect any tubes when the test pressures are applied.
(a)
Slowly bleed the input pressures to ambient before the tubes are disconnected.
1
Do not do more than the maximum recommended altitude rate of change of 6000 feet
per minute (1829 m/min).
2
Do not do more than the maximum recommended airspeed rate of change of 200
knots-per-minute (370 km/min).
(7)
Control the pitot system pressure or vacuum to keep the airspeed between 180 to 300 knots.
(a)
Do not let the airspeed go to more than 300 knots or fall below 180 knots.
(b)
Do not let the altimeter indication fall more than 100 feet (30.48 m) below sea level or higher
than 45,000 feet (13,716 m).
(8)
During the test of the static system, use static fittings or red vinyl tape to seal the opposite static
port surface.
NOTE:
If the opposite static port is vented to the atmosphere the test results will be invalid.
CAUTION:
Do not use soap and water, or any liquid, to do a leak test of the
pitot and static system. This can cause damage to the system.
(9)
Any time a pitot or static line is disconnected, you must do a leak check of the pitot and static
system.
34-11-00
Page 602
© TEXTRON AVIATION INC.
Feb 23/2022
ICA-525B-34-00004
Form 2261 Rev 1