©1999 Navia Aviation AS 21833-3.4 Maintenance Procedures
OPERATING MANUALNORMARC 7013
INSTRUMENT LANDING SYSTEM
C-17
d. Detailed Procedure.
1. Simulate a continuous alarm, or from the RMM perform a station integrity check.
2. Allow a shutdown to occur.
3. Determine that the proper remote and local alarm indications occurred.
4. If remote restore capability is installed, restore the facility from the remote control point or
allow the auto-restart circuit to restore the facility.
5. Make an entry in the facility log that this check was completed.
5-42 thru 5-44 reserved.
5-45 CAPTURE-EFFECT MONITOR.
a. Object.
This procedure provides a method to determine whether the glide slope monitor alarm points
are within the reference values established during the reference flight inspection.
b. Discussion.
1. The glide slope monitor is used to ensure the integrity of the glide slope system by permit-
ting the glide slope to operate only if certain system parameters are within the limits estab-
lished during the reference flight inspection. This performance check is accomplished by
adjusting the transmitting equipment to cause a monitor alarm and then verifying that the
radiated parameters are within established reference values. If a radiated parameter is
found outside the established reference values, it must be determined if the condition is
due to monitor drift. If so, the monitor alarm points must be tightened to ensure that for
day-to-day monitor drift, the monitor will alarm whenever the radiated signal parameters
are at or beyond the established reference values.
2. The reference data must be measured carefully. Rf power measurements using the Bird
Wattmeter must always be accomplished with the same meter and elements. The ele-
ments shall be clearly marked. In addition to the rf wattmeter readings, it is recommended
that a digital voltmeter (dvm) be used to obtain reference readings for carrier and sideband
power in normal, wide, and narrow alarm. These reference readings can be made with
greater repeatability by using the dvm than by using the analog wattmeter. This is done by
connecting a dvm, set to measure dc voltage, to the detector element output in place of the
normal meter. Improved consistency in dvm readings will result if the dvm input is shunted
with a 1400-W ±1 percent resistor. This resistor presents the same load to the detector
elements as the normal analog meter. If the reference readings are made with the load
resistor in place, all future measurements must be made in this configuration.
3. Measurements taken with built in test equipment (BITE) (i.e., power, DDM, modulation,
etc.) must be verified for accuracy with external test equipment as outlined in this hand-
book. This is to ensure that repeatable results are obtained and maintained in the case of
internal equipment failure and/or replacement of modules that effect BITE measurements.
4. For equipment that uses a maintenance data terminal (MDT), when adjusting the phase of
a signal, the number of degrees adjusted may need to be determined from a reference
index number. This may be accomplished via a table or conversion chart, usually found in
the equipment TI. For this reason, the alternate methods described in the procedures (i.e.,
the addition and removal of line lengths, elbows, etc.) is recommended.
5. The monitor DDM values are the monitor input values as measured with a PIR or the digital
readout values of the monitor or as measured with BITE/MDT. No tolerance is established
for the DDM values. They are used to detect trends such as system or monitor drift.
6. This performance check requires a line entry on Navia Aviation Form “CEGS Monitor Ref-
erence Data”. The reference data line contains the reference data used to perform a mon-
To Next Page
Loading...