2.10.1 NAV Preflight Tests
For this series of in-aircraft tests, the aircraft's engine(s), rotating beacon, electrical
and avionics equipments should be operating. Note any abnormal interaction of
interference (ignition or rotating beacon noise, abnormal meter deflection, compass
deviation, etc.) observed during these tests.
The following procedure requires a ramp type piece of test equipment such as that offered by
Tel-Instrument Corp. or Instrument Flight Research, Inc.
A. Keep-Alive and Transfer checks.
1.
Turn the MK-12DR ON. The Active display shall show a valid NAV
frequency and the Standby 110.50.
2.
Press the NAV transfer button and observe that the Active and
Standby frequencies exchange position.
3.
Reset the Active display to 114.15.
4.
Turn the MK-12DR OFF and wait a minimum of 10 seconds. Turn
the MK-12DR ON and observe that the Active display reads 114.15
and the Standby 110.50.
B. General
1.
Set NAV Active channel to a VOR frequency.
2.
Rotate the VOL-IDENT control clockwise until NAV Receiver noise
is heard in the speaker and headphones. (Note: IDENT knob must be
pulled out). Note presence of NAV and GS warning flags and
centered Left-Right and Up-Down needles.
3.
Modulate test equipment 30% with 1020 Hz.
4.
Note presence of adequate Audio level. Depress VOL-IDENT knob
and note decrease in volume level.
C. VOR
1.
Set NAV Active display to a desired VOR frequency.
2.
Set test equipment to desired VOR frequency. Modulation should be a
composite VOR signal. TO/FROM switch set to the TO position.
3.
Set test equipment and Indicator OBS to a Zero degree course. The
Left-Right needle should center within ±2.0 degrees ( ±1.5 degrees for
TSO'd indicator) with a TO flag.
4.
Turn indicator OBS knob first to 10 degrees, then to 350 degrees. The
Left-Right needle should deflect to the left and right of center.
JUNE 1996
REV. C
15
