(e)
Message slot 6 - Ground clutter suppression message located at bottom left of the indicator displays IDNT when the ground clutter suppression is selected. Normally the message slot is blank.
(f)
Message slot 7 - Stabilization status message located at bottom right center. For stabilized operation, if the INS provides proper inputs, this slot will be blank. A flashing ATT message will be displayed when an attitude input failure is detected (INS OFF or providing invalid pitch or roll signals). A SAT message will be displayed when system stabilization limits are exceeded due to unusual attitude maneuvers. All messages are a blue color.
EFFECTIVITY
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(g)
Message slot 8 - Antenna tilt located in bottom right corner of the indicators. Message displays the antenna tilt angle in 0.25-degree increments in blue (cyan), from 15.00(X) to 15.00(X) where (X) represents an arrow pointing upward or downwards depending on the direction of antenna tilt selected. If the antenna tilt position is different than the position annunciated, a flashing FAIL message is displayed in slot 2 and an ANT message in slot 4).
(h)
Message slot 9 - System message located below message slot 3 (range) this message displays which system is selected. This slot will be blank when system 1 is selected and will display S2 when system 2 is selected.
(18) Weather Radar Mode Displays (Fig. 5)
(a) The weather radar mode displays are described as follows:
1) WX (weather)- the indicators show area of heaviest rainfall in red, the next lower level of rainfall in yellow, and the least rainfall in green.
2) AF 160, 162-171; WX+T (weather plus turbulence) - the indicators display weather the same as in the WX mode. In addition any turbulence return which indicate area of rainfall and winds within 50 miles of the airplane are displayed in magenta.
3) MAP - the indicators display terrain mapping returns in yellow and green. The most reflective returns are displayed in yellow and the least reflective returns are displayed in green.
4) AF 183,184; SCH (weather with adjustable gain) - the indicators show areas of heaviest rainfall in red, the next lower level of rainfall in yellow, and the least rainfall in green. The gain control provides an increase in receiver sensitivity. Turbulence is shown in magenta with range selections of 20 to 40 miles.
(19) Weather Radar Status and Fault Message Displays (Fig. 6)
(a) The weather radar indicator status and fault message displays are described below: 1) AF 160, 162-171;
A yellow WEAK message in slot 2 indicates an out of calibration condition in the receiver/transmitter. A flashing yellow FAIL message will be present when the system performance monitoring circuits detect a fault. The detected fault will be displayed in message slots 6, 7, 8, or 9 on the left side of the indicator.
2) AF 183, 184; A yellow WEAK message in slot 2 indicates an out of calibration condition in the receiver/transmitter. A flashing yellow FAIL message will be present when the system performance monitoring circuits detect a fault. The detected LRU faults will be displayed in message slot 4, on the left side of the indicator.
D. Self-Test (Fig. 6)
EFFECTIVITY
AF 160, 162-171, 183, 184 CONFIG 4 01 Page 37 Sep 25/9434-43-00
(1)
Selecting the TEST mode on the weather radar control panel results in a system check of circuits not continually monitored by the performance monitor.
(2)
Self-test is designed to compliment the continuously monitored functions by exercising the system for LRU isolation and operator confidence. The self-test also checks the data buses between the R/Ts and the indicators. Self-test of the weather radar system components is described below. R/T -The transmitter transmits for less than 1 second to
check proper generation and then is muted for the remainder of the self-test. A proper test pattern verifies correct operation of the weather radar system.
Antenna - The R/T unit automatically exercises the antenna unit to confirm proper operation. It commands a full left sweep followed by a full right sweep to the azimuth limits. Simultaneously, it commands a full up-tilt followed by a full down-tilt to the tilt limits. Upon successful completion of the antenna testing sequence, the R/T unit commands the antenna unit to drive to a dead-ahead azimuth position and to drive to a zero-tilt position, where it stops at the electrical zero positions for the remainder of the test. The antenna test sequence requires less than 8 seconds. Proper antenna tilt operation is verified by observing the tilt readout on the indicator. The tilt readout stops at +15 degrees up, slews to 15 degrees down, and then slews up to zero degrees and stops.
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本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航3(113)
