Technical data

13773-001
34-10
Page 4 30 Nov 2000
(c) Blow clean, low-pressure air from the disconnected line at the airspeed indicator to the
pitot tube.
(d) Connect line at airspeed indicator.
(e) Perform pitot system leakage test. (Refer to 34-10)
(f) Install glareshield. (Refer to 25-10)
(4) Inspection/Check - Pitot System Leak Test
The following procedure outlines inspection and testing of the pitot system. Perform this test any
time an instrument, fitting, line, or pitot head is disconnected.
(a) Acquire necessary tools, equipment, and supplies.
(b) Fasten surgical hose and sphygmomanometer bulb over pitot tube.
(c) Pump bulb until airspeed indicator registers 115 KIAS.
(d) Close check valve
(e) Wait 15 seconds for airspeed indicator to stabilize.
(f) Observe airspeed indicator for one minute. If leak is present, indicated airspeed will
decrease.
(g) Slowly release check valve so pressure is reduced gradually to prevent instrument dam-
age.
(h) If test reveals a leak in system, check all connections for tightness and repair faulty com-
ponents.
B. Alternate Static Source Valve (See Figure 34-101)
(1) Removal - Alternate Static Source Valve
(a) Open circuit breaker panel to gain access to alternate static source valve.
(b) Identify, disconnect, and cap off line from alternate static source valve.
(c) Remove set screw attaching knob to alternate static source valve.
(d) Pull knob off alternate static source valve.
(e) Remove screw securing alternate static source valve to console and remove valve.
(2) Installation - Alternate Static Source Valve
(a) Position alternate static source valve to console and install mounting screw.
(b) Connect static line to alternate static source valve.
(c) Push knob onto alternate static source valve and install set screw.
(d) Perform static system leakage test. (Refer to 34-10)
(e) Close and secure circuit breaker panel.
(3) Inspection/Check - Purging the Static System
Static air pressure lines must be kept clear and connections tight. A water trap and plug, located
at the low point of the static system directly behind the center console and underneath the cabin
floor, is used to trap and then drain water from the system. However, moisture may collect at
other points of the system. To purge the static system, proceed as follows:
Description P/N or Spec. Supplier Purpose
Sphygmomanometer Pres-
sure Bulb with Check Valve
21-140 Omron Health Care
Inc.
Simulate ram air
pressure.
Surgical Hose 21-321 Omron Health Care
Inc.
Bulb attachment to
hose.