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 crew 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.

PFD FAILURE, DUAL SYSTEM

If PFD1 fails, COM1 and NAV1 display a red X on both remaining displays. NAV1 will be unavailable.
COM1 automatically tunes 121.500 MHz, but the frequency is not shown. The COM1 emergency frequency is
available to both the copilot and pilot.
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Figure 4-55 Stuck Microphone Alert
Emergency Channel
Loaded Automatically
Figure 4-56 COM Tuning Failure
Figure 4-57 Frequency Section of MFD Display after PFD1 Failure
Garmin G900X Pilot's Guide
Emergency Channel
Loaded Automatically
190-00726-00 Rev. J