Honeywell KA 54 - Manual (Page 67)

N
KRA 405B RADAR ALTIMETER INSTALLATION MANUAL
Page 3-2
006-10536-0010 Rev. 10 Oct/2005
• DH Lamp:
This lamp lights when the Decision Height is reached. The lamp can be
turned off by pushing the lamp in. The lamp can be turned on again,
when below the decision height, by depressing the lamp a second time.
Once turned off, the DH lamp will be automatically armed upon climb out
as the aircraft passes through the DH altitude. Pressing the self-test
button will also turn on the DH lamp if the DH bug is set above 50 feet.
3.2 NORMAL OPERATION
A. PREFLIGHT
(1) Turn on primary aircraft power.
(2) Adjust the DH knob on the KNI 415/416 Radar Altimeter Indica-
tor to set the DH bug to 25 feet.
(3) Depress the TEST button. The indicated altitude should be 50
± 5 feet and the flag should come into view. The DH lamp
should be out.
(4) With the TEST button depressed, slowly increase the DH bug
until the DH lamp lights. The bug should be 50 ± 5 feet. The
lamp should be lit at all altitudes above 50 feet.
(5) Release the TEST switch. The warning flag should move out of
view and the indicated altitude should be 0 feet, nominal.
B. TAXI
When taxiing to and from the ramp, the DH light option may be turned
off by simply pressing the DH lamp. Once off, the lamp may be turned
on again by pressing the DH lamp or pressing the TEST button, if the
DH bug is set above 50 feet. Climbing past the decision height
(indicated by the DH bug) arms the DH lamp so during the approach
the lamp will light upon reaching the decision height.