INSTALLATION APPROVAL
TEST
PROCEDURE
NAT Part #:
NTX403
Description:
Remote Mount UHF FM Transceiver
Document #:
NTX403\634-0
Rev:
1.00
1.
Post Installation EMI Test
The purpose of this test is to identify any interference that the NTX403 may cause with
existing aircraft systems.
2. Test
Conditions
The NTX403 should be installed and function tested. The antenna VSWR should be
checked. A forward/reverse power check with an in-line wattmeter should show no
more than 10% reflected power. For the following tests, ensure that the transmit power
is set to HI.
3. Methodology
Most of the EMI tests can be accomplished on the ground. In some cases flight testing
is required or is easier. If the aircraft is approved for IFR operations, then it is mandatory
that interference between the NTX403 Airborne FM and the approach aids be checked
in flight.
The GPS should be operational and navigating with at least the minimum compliment of
satellites. The VHF comm should be set to the frequencies indicated with the squelch
open. VOR/DME receivers should be set to the frequencies indicated and selected for
display. If possible, set up a DME ramp test set on the frequencies indicated and adjust
the output until the flags are out of view. The transponder and encoder should be
monitored with ramp test equipment. Set the output of the transponder test set to 3 dB
above the output necessary to achieve 90% reply. If possible set the ADF to a nearby
navigation station.
Modulate the NTX403 transmitter on the indicated frequencies for at least 20 seconds.
Observe the GPS for any degradation in satellite status or availability or flags. Listen for
any noise or detected audio signals on the VHF comm(s). Listen for any noise or
detected audio signals on the VOR/LOC receiver audio; look for any movement of flags
or needles on the VOR/LOC/GS navigation display(s). Observe the transponder for any
loss of reply or spurious reply.
List the power plant, fuel and other electric instruments in the chart provided and note
any anomalies that occur while transmitting. Assess the results.
If the aircraft is equipped with an autopilot or a stability augmentation system, then test
fly the aircraft and verify that operation of the NTX403 transceiver does not have
adverse effects on these systems. After checking for gross effects at a safe altitude, fly
Rev. 1.00
Apr 28, 2005
Page 1 of 5
ENG-FORM: 634-0101.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
