Honeywell KA 54 - Manual (Page 68)

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KRA 405B RADAR ALTIMETER INSTALLATION MANUAL
Page 3-3
006-10536-0010 Rev. 10 Oct/2005
C. IN FLIGHT OPERATION
At normal cruise altitudes above 2000 feet, the indicator pointer
is behind the mask and the warning flag is hidden from view above
2,500 feet. A Flight Control System (FCS) warn is a failure warning
signal to systems requiring accurate above ground level (AGL)
altitude information. The FCS warn presents a red flag during
operation above 2000 feet, during self test, loss of power, and loss
of signal strength to alert the pilot to possible failures.
D. APPROACH
During the actual approach, the Radar Altimeter System provides
altitude and altitude trip information to the Flight Control System.
When the approach plans are reviewed prior to beginning the actual
approach, the pilot should set the DH bug to the decision height
altitude, and check altimeter operation. When decision height is
reached, the DH Lamp lights to alert the pilot that a decision should
be made. The DH Lamp may then be turned off by pressing the lamp in.
E. PUSH-TO-TEST MODE
(1) To check altimeter operation, depress the TEST button. The
following should be noted on the altimeter:
a. 50 ± 5 feet should be indicated.
b. The flag should come into view.
c. The DH lamp should light (if the DH setting is above 50
feet).
d. Verify that the pointer comes on scale at 2000 feet AGL
by using the baro corrected barometric altitude as a
reference. (This reference is for self test only and
should not be used as an absolute altitude).
(2) If altimeter does not operate as specified above, refer to
Self-Test Diagnostics, paragraph 3.3 SELF-TEST DIAGNOSTICS .