190-01134-11
GMA 350/350c/350H/350Hc Installation Manual
Rev. J
Page 3-7
3.8.6
Verify Telephone and Music Operation (if installed)
1. Deselect or turn off other audio sources (MKR, transceivers, receivers, alerts). Some
configurations may mute telephone and/or music audio when aircraft audio is present.
2. From the pilot’s headset position, initiate a phone call and verify that two-way communication
over the telephone can be heard when selected (refer to the applicable pilot’s guide for
information on how telephone and music audio can be distributed and insure that it is configured to
be heard by the pilot).
3. Verify that all installed music sources can be heard when selected (refer to the applicable pilot’s
guide for information on how telephone and music audio can be distributed and insure that it is
configured to be heard by the pilot).
3.8.7
Marker Beacon Operation (if installed)
1. With a marker signal generator/transmitter test set, generate Marker Tones.
2. From the pilot headset position, verify that marker audio can be heard when selected.
3. If the system includes integrated lamp annunciation and/or if external lamps are installed,
verify that each marker tone illuminates the proper lamp.
NOTE
The Marker Lamps will operate even if the marker audio is not selected.
Outer Marker – Blue Lamp – 400 Hz (AM or received audio tone)
Middle Marker – Amber Lamp – 1300 Hz (AM or received audio tone)
Inner Marker – White Lamp – 3000 Hz (AM or received audio tone)
4. If the system is configured and/or wired to allow both HI and LO sensitivity operation, verify that
during HI SENS operation, the RF threshold is more sensitive (marker audio/indication occurs as a
lower RF power).
3.8.8
Other Optionally Installed or Configured Inputs/Outputs
Verify any other installed/configured inputs and outputs operate as described in the applicable pilot’s
guide. Possible examples include PTC (voice command “Push to Command”) keys, ICS keys, Passenger
ISO (isolation) toggle key, clearance recorder Play key, PA Mute output, PA Mode Selected output, Com
Active output, and Middle Marker Sense output.
3.9 Continued Airworthiness
Other than for regulatory periodic functional checks, maintenance of the GMA 350/350H is “on condition”
only.
