Bendix/King KFC 400 - Diagnostics

Diagnostics
Should an autopilot “Dump” occur,
the maintenance facility will be assis-
ted
if the crew can provide information
from the KFC
400 built in diagnostics.
The steps
to follow are:
1. Record whether AP FAIL, TRIM
FAIL or both annunciators are
illuminated. Also note whether any
of
the axis failure LED’s on the KMC 440
are illuminated.
2. Prior to removing power to the
system
or starting self test enter the
diagnostic mode.
a. Press and hold the AP discon-
nect switch
on the control wheel.
b. Simultaneously push AP
& YD
buttons for approximately
3
seconds until all annunciators
illuminate.
buttons.
c. Release AP Disc, AP
& YD
3. At this point the Roll LED should be
illuminated. Any other annunciators
illuminated on the KMS
446 and
KMC
440 should be recorded under
the heading
“Roll”.
4. Click the vertical trim switch once in
the nose up direction. The Pitch LED
should illuminate. Record any other
annunciators which are illuminated on
the KMS
446 and KMC 440 under the
heading “PITCH”.
5. Click the vertical trim switch once
more in the nose up direction. The
Yaw
LED should illuminate. Record
any other annunciators which are illu-
minated on the KMS
446 and
KMC
440 under the heading “Yaw”.
6. Exit diagnostics by repeating steps
2. a. b. & c. waiting until all annuncia-
tors extinguish.
The autopilot is now returned to
its
normal operational state.
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