Installation Instructions

GTN 6XX/7XX AML STC Installation Manual 190-01007-A3
Page 5-90 Rev. 4
5.7.2 Signal Acquisition Check
NOTE
All other avionics should be turned off at the start of this test, with the GTN powered
on.
Ensure the GTN is able to acquire sufficient satellites to compute a GPS position. From the Home page,
touch the System key and then touch the GPS Status key. Under ‘GPS Solution’, ensure that a ‘3D Fix’
or ‘3D Diff Fix’ is obtained. If the unit is unable to acquire satellites, move the aircraft away from
obstructions which might be shading GPS reception. If the GPS solution does not improve, check the
GPS antenna installation.
NOTE
After installation, the initial acquisition of position can take up to 20 minutes.
Subsequent acquisitions will not take as long.
Once GPS position information is available, perform the following steps:
1. On the GPS Status Page, verify that the LAT/LON agree with a known reference position.
2. While monitoring the GPS Status page, turn on other avionics one at a time and check the GPS
signal reception to make sure it is not affected (no significant signal degradation).
3. Before proceeding with the VHF COM interference check, ensure that any connected equipment
is transmitting and/or receiving data from the GTN and is functioning properly.