011-01257-20

Cockpit audio selection and crew controls

The front panel provides separate transmitter selection for COM1, COM2 and COM3 and corresponding receiver-audio selection. Dedicated controls are provided for NAV1, NAV2, DME, ADF, auxiliary audio, music, speaker, telephone and passenger address when those sources are installed and enabled. The knob arrangement supports master audio and intercom volume or squelch adjustment.

The exact 011-01257-20 Cabin version includes cabin and intercom functionality appropriate to its approved configuration. Garmin documentation lists up to five intercom positions for the GMA 1347D, with separate pilot and passenger volume control paths. It also provides manual squelch, cabin intercom and playback controls. Actual passenger stations and jacks are external installation items and are not included merely because the panel supports them.

Marker beacon, recording and fail-safe functions

The GMA 1347D incorporates marker beacon controls, including marker mute and sensitivity selection. A compliant installation requires the appropriate marker beacon antenna, coupler, coaxial cable and approved routing. Garmin lists the antenna kit separately, and the antenna is mounted outside the aircraft in accordance with the installation requirements rather than inside the cabin.

The panel supports digital recording playback and includes fail-safe audio behavior for essential communication paths. The red DISPLAY BACKUP control is used for the applicable reversionary display function in an integrated cockpit. These controls must be interpreted according to the aircraft flight manual supplement and system documentation; a visible button does not prove that every optional mode is enabled in a particular aircraft.

Electrical, interface and installation data

The GMA 1347D requires a 28 V DC supply and draws no more than 1.75 A at 27.5 V. Garmin specifies an operating temperature range from −45 °C to +70 °C and an altitude qualification of 55,000 ft. The audio architecture provides three transceiver inputs, five receiver inputs and four unswitched inputs, with 500-ohm input impedance and at least 60 dB input isolation.

The panel uses two 78-pin rear connectors, identified as J3471 and J3472. Its bezel measures 7.70 in (196 mm) high and 1.30 in (33 mm) wide; the rack is 6.30 in (160 mm) high and 1.325 in (34 mm) wide. Depth behind the aircraft panel, including connector backshells, is 7.79 in (198 mm). Unit mass is 1.7 lb (0.8 kg), increasing to 2.4 lb (1.1 kg) with rack and connectors.

Condition and ordering of 011-01257-20

This 011-01257-20 GMA 1347D Cabin position is offered in Serviceable condition from partner stock with a six-month warranty. Price follows the matching public comparison and agreed minimum multiplier. The exact serial number, traceability, software or modification level, supplied release documentation and included installation hardware are reconfirmed before order acceptance.

For a quotation, specify MPN 011-01257-20, model GMA 1347D Cabin, quantity, destination and certification requirements. Confirm the required rack, connector kit, backplate, marker antenna equipment and aircraft approval. The installation should also be checked for panel space, rear support, cooling airflow, electrical bonding and the approved relationship between the audio panel and both integrated avionics units. Other identified units appear in the Garmin / BendixKing / Honeywell / Collins category. They are related catalog positions and must not be treated as interchangeable without approved data.