(2)
Repeat step 3.B.(1) with self-test switch set to SLEW, HOLD, and FAIL WARN.
C. Remove electrical power if no longer required.
5C8
Aug 01/95 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 34-12-11 Page 401
AIR DATA PRESSURE INDICATORS - REMOVAL/INSTALLATION
1. Remove Indicator
A. Open applicable indicator circuit breakers on panel P6 or P18.
NOTE: If servoed or servo-pneumatic indicator, also open applicable air data computer circuit breakers.
B. Loosen instrument mounting clamp and slide indicator out of instrument panel.
CAUTION: DRAW INDICATOR OUT OF INSTRUMENT PANEL WITH CARE TO AVOID STRESS AND/OR DAMAGE TO CABLE AND PNEUMATIC HOSES (IF ATTACHED) AT BACK OF CASE.
C. Disconnect electrical connector on rear of indicator case.
CAUTION: TO AVOID DAMAGE TO PNEUMATIC OR SERVO-PNEUMATIC INSTRUMENTS, PITOT AND STATIC SYSTEM PRESSURES MUST BE AT AMBIENT BEFORE PROCEEDING.
D. Disconnect pitot static system hoses from rear of indicator case (if applicable).
2. Install Indicator
A. Connect electrical cable to connector on rear of indicator case.
CAUTION: TO AVOID DAMAGE TO PNEUMATIC OR SERVO-PNEUMATIC INSTRUMENTS, PITOT AND STATIC SYSTEM PRESSURES MUST BE AT AMBIENT BEFORE PROCEEDING.
B. Connect pitot static system hoses to rear of indicator case (if applicable).
C. Slide indicator into position in instrument panel and secure with instrument mounting clamp.
CAUTION: INSERT INDICATOR INTO PANEL WITH CARE TO AVOID STRESS AND/OR DAMAGE TO CABLE AND PNEUMATIC HOSES (IF ATTACHED).
D. Close applicable circuit breakers opened in step 1.A.
E. If any connection in the pitot static system (other than a quick disconnect) has been broken, perform a low range leak test of the applicable pitot static system, (Ref 34-11-0, A/T).
NOTE: Place mode switch on STBY (BARO) or OFF position on servo-pneumatic indicators.
501
Aug 01/96 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 34-12-21 Page 401
3. Test Indicator
A. Provide electrical power.
B. Check that panel light circuit breakers on panel P6 are closed.
C. Check that indicator illumination lights are on.
NOTE: For servoed or servo-pneumatic indicators, air data computer should be known to be functioning properly before this test.
D. Check that indicator failure warning flags are out of view.
NOTE: Place mode switch on servo-pneumatic indicator in CADC or ON position.
E. Remove electrical power if no longer required.
501
34-12-21 Page 402 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. May 01/01
AIR DATA TEMPERATURE INDICATING SYSTEM - DESCRIPTION AND OPERATION
1. General
A. The temperature of the outside air is used to calculate air density, which is required for correct adjustment of the airplane engines.
2. Total Air Temperature Probe
A. The outside air temperature probe contains a noninductive resistive transducer sensing elements and an anti-icing heater. Temperature variations of the slipstream airflow through the probe and sensor causes the element resistance to vary, thus providing air temperature data to the total air temperature indicator (Fig. 1 and 2).
B. In flight, heating of the probe assembly is controlled by a switch on the pilots' overhead panel. Refer to Pitot Tubes and Temperature Probe Anti-Icing System, Chapter 30.
3. Total Air Temperature Indicator (GJ ALL EXCEPT B2509-B2510)
A. The total air temperature sensor resistance is electrically included as one leg of a dc bridge circuit across which the electro-mechanical movement of the total air temperature TAT indicator is connected. A change in air temperature will cause a consequent change in resistance of the sensor, and thus proportionately unbalance the bridge. This unbalance produces a corresponding current flow through the indicator movement, rotating the pointer, and displaying total air temperature on the peripheral scale between -70 and +50 degrees centigrade.
4. Total Air Temperature Indicator (GJ B2509-B2510)
A. The total air temperature TAT indicator provides a visual indication of total air temperature as sensed by a total air temperature probe. Total air temperature is read on a three-drum numerical counter from -60 to +60 degrees centigrade in 0.1-degree increments.
B. Indicator input is a resistance from the total air temperature probe that varies as a function of total air temperature.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：737 AMM 飞机维护手册 导航 NAVIGATION 1(33)
