Abnormal Operation; Stuck Microphone; Com Tuning Failure; Audio Panel Fail-Safe Operation - Garmin G1000H Pilot's Manual

4.7 ABNORMAL OPERATION

Abnormal operation of the system includes equipment failures of the system 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 MIC1, MIC2 or MIC3 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 (left ear only if stereo) and
microphone directly to the COM1 transceiver. Audio is not available on the speaker during Fail-safe operation.
190-01255-00 Rev. A
Figure 4-47 Stuck Microphone Alert
Emergency Channel
Loaded Automatically
Figure 4-48 COM Tuning Failure
Garmin G1000H Pilot's Guide for the Bell 407GX
™
AUDIO PANEL AND CNS
133