Abnormal Operation; Stuck Microphone; Com Tuning Failure; Audio Panel Fail-Safe Operation - Garmin G900X Pilot's Manual

AUDIO PANEL AND CNS

4.7 ABNORMAL OPERATION

Abnormal operation of the G900X includes equipment failures of the G900X components and failure of
associated equipment, including switches and external devices.

STUCK MICROPHONE

If the push-to-talk (PTT) Key becomes stuck, the COM transmitter stops transmitting after 35 seconds of
continuous operation. An alert appears on the PFD to advise the pilot of a stuck microphone.
The COM1 MIC or COM2 MIC Key Annunciator on the Audio Panel flashes as long as the PTT Key remains
stuck.

COM TUNING FAILURE

In case of a COM system tuning failure, the emergency frequency (121.500 MHz) is automatically tuned in
the radio in which the tuning failure occurred. Depending on the failure mode, a red X may appear on the
frequency display.

AUDIO PANEL FAIL-SAFE OPERATION

If there is a failure of the Audio Panel, a fail-safe circuit connects the pilot' s headset and microphone directly
to the COM1 transceiver. Audio will not be available on the speaker.

REVERSIONARY MODE

The red DISPLAY BACKUP Button selects Reversionary Mode for both displays. Reversionary Mode
operation displays flight and engine information on both the PFD and MFD, in case of display failure.
See the System Overview Section for more information.
4-36
Figure 4-45 Stuck Microphone Alert
Emergency Channel
Loaded Automatically
Figure 4-46 COM Tuning Failure
Figure 4-47 Reversionary Mode Button
Garmin G900X Pilot's Guide 190-00726-00 Rev. A