Installation Instructions

190-01007-A3 GTN 6XX/7XX AML STC Installation Manual
Rev. 4 Page 5-107
5.8 Flight Checks
All GTN functions that cannot be adequately tested on the ground will require a flight check. Even if all
functions can be verified on the ground, a flight check is required as final installation verification. Verify
system operation as described in the following sections.
The analog deviation (LEFT/RIGHT and UP/DOWN), TO/FROM, and FLAG (lateral and vertical)
outputs to a CDI or HSI should be verified in flight with potential sources of electrical noise such as
autopilot, flaps, gear, heater blowers, etc. operating. Lateral deviation and flags may be checked with
either GPS or VOR/ILS, and vertical deviation and flags must be checked with glideslope. Verify that the
flags are hidden at the correct times, and that the flag is in view at the correct times. Also verify during
flight that any placards and labels added as part of the GTN installation are readable in all anticipated
cockpit lighting conditions.
5.8.1 GPS Flight Check
1. Verify that GPS position is not lost during normal aircraft maneuvering (e.g. bank angles up to 30
degrees and pitch angles associated with take-off, departures, approaches, landings, and missed
approaches as applicable). If GPS position is lost, a “Loss of GPS Navigation” message will be
displayed.
2. Enter and activate a flight plan on the GTN by touching the Direct-To key and entering a
waypoint. Fly the flight plan and verify that the display of flight plan data is consistent with the
CDI indication (deviation, TO/FROM…) in the pilot’s primary field of view.
5.8.2 VHF COM Flight Check (GTN 635/650/750)
After the installation is complete, a flight check is required to ensure satisfactory performance. To check
the communications transceiver, maintain an appropriate altitude and contact a ground station facility at a
range of at least 50 nautical miles. Contact a ground station in close proximity. Press the COM volume
knob to select manual squelch and listen for any unusual electrical noise, which would increase the
squelch threshold. If possible, verify the communications capability on both the high, low, and mid bands
of the VHF COM band. It may be required by the governing regulatory agency to verify operation of the
COM transmitter and receiver at the extents of a ground facility’s service volume (e.g., FAA AC 23-8A).
5.8.3 VOR Flight Check (GTN 650/750)
1. Tune a local VOR station within 50 miles.
2. Verify the audio IDENT and voice quality and verify that no objectionable electrical interference
such as magneto noise is present.
3. Verify the Morse code decoder IDs the station (95% probability).
4. Fly to and from the station.
5. Verify NAV flag, TO/FROM flag, and CDI are operational.
It may be required by the governing regulatory agency to verify operation of the VOR receiver at the
extents of a ground facility’s service volume (e.g., FAA AC 23-8A).
5.8.4 ILS Flight Check (GTN 650/750)
1. Tune an ILS at a local airport.
2. Verify the audio IDENT and audio quality and verify that no objectionable electrical interference
such as magneto noise is present.
3. Verify the Morse code decoder IDs the station (95% probability).
4. Fly the approach.
5. Verify NAV flag, GS flag, and CDI and VDI are operational.