SUPPLEMENT 2 GARMIN AUDIO PANEL (GMA 340) GENERAL DESCRIPTION: Modification PAC/XL/0014 Modification PAC/XL/0014 installs a Garmin GMA audio panel in the airplane. SECTION 1 GENERAL The Garmin GMA 340 is a panel mounted audio panel. KEY FUNCTIONALITY The GMA 340 has a number of keys which control the following functions: PILOT Rotation of the smaller inner knob turns the unit ON/OFF and adjusts the pilot s Intercom System (ICS) volume. The unit is turned off by rotating the knob fully counter clockwise into the detent. To turn the unit on, rotate the knob clockwise past the click. To increase the volume rotate the knob clockwise and to decrease the volume rotate the knob counter clockwise. A fail-safe circuit 9-2-2 DATE ISSUED: 1 December 2003
connects the pilot s headset and microphone directly to COM 1in case power is interrupted or the unit is turned off. The larger outer knob controls the pilot s Voice Activated Intercom Squelch level. Rotating the knob clockwise increases the amount of microphone Voice Activated (VOX) required to break squelch. Full counter clockwise rotation of the knob is the HOT MIC position (no squelch). COPILOT Rotation of the small inner knob controls the copilot and passenger ICS. To adjust the volume on the copilot s ICS ensure the knob is pushed in. To increase the volume rotate the knob clockwise and to decrease the volume rotate the knob counter clockwise. To adjust the passenger ICS volume pull the knob out. To increase the volume rotate the knob clockwise and to decrease the volume rotate the knob counter clockwise. The larger outer knob controls the copilot s and passenger s VOX squelch level. Rotating the knob clockwise increases the amount of microphone Voice Activated (VOX) required to break squelch. Full counter clockwise rotation of the knob is the HOT MIC position (no squelch). MKR MUTE SENS The marker beacon audio is initially selected by pressing the MKR/MUTE button. If no marker beacon signal is received, then a second button press will deselect the marker audio. If the second button press occurs while a marker beacon signal is received, then the marker audio is muted but not deselected. The button s LED will remain lit to indicate that the source is still selected. When the current marker is no longer received, the audio is automatically un-muted. While in the muted state, pressing the MKR/MUTE button deselects the marker audio. The button s LED will extinguish to indicate that the marker audio is no longer selected. This button selects either high or low sensitivity as indicated by the HI or LO LED being lit. Low sensitivity is used on ILS approaches while high sensitivity allows operation over airway markers or to get earlier indication of nearing the outer marker during an approach. NOTE The marker beacon audio level is aligned at the factory to produce its rated audio output. DATE ISSUED: 1 December 2003 9-2-3
AOM The Airways (A), Outer (O) and Middle (M) marker beacon lamps operate independently of any audio selection and cannot be turned off. NOTE The lamp and audio keying for ILS approach operation are summarized below. Audio Audio Keying Lamp Actuated Frequency 400 - - - - - - - - Blue (Outer) 1300 - - - - Amber (Middle) 3000 White (Airway/Inner) COM 1/2/3 MIC Selection of COM 1, COM 2 or COM 3 for both MIC and audio source is accomplished by pressing either COM 1 MIC, COM 2 MIC or COM 3 MIC transmitter (Audio/Mic) selection buttons. The active COM audio is always heard on the headphones. When a microphone is keyed, the active transceiver s MIC button LED blinks approximately once per second to indicate that the radio is transmitting. Audio level is controlled by the volume control on the selected radio unit volume control. COM 1/2/3 COM1/2 Pressing the COM 1, COM 2 and COM 3 button allows the audio on the associated radio to be heard. When selected this way, they remain active as audio sources regardless of which transceiver has been selected for microphone use. Pressing the COM1/2 button activates the split COM function, if fitted. When this mode is active, COM 1 is dedicated solely to the pilot for MIC/audio while COM 2 is dedicated to the copilot for MIC/audio. The pilot and copilot can simultaneously transmit in this mode over separate radios. Both pilots can still listen to COM 3, NAV1, NAV2, DME, ADF and MKR as selected. The split COM mode is cancelled by pressing the COM ½ button a second time. When in the split COM mode the copilot may make PA announcements while the pilot continues using COM1 independently. When the PA button is pressed after the split com mode is activated, the copilots mic is output over 9-2-4 DATE ISSUED: 1 December 2003
the cabin speaker when keyed. A second press of the PA button returns the copilot to normal split COM operation. NAV1/2, ADF, DME Pressing NAV, NAV2, ADF and DME selects the audio source for the associated navigation unit. A second press deselects the audio. Audio level is controlled by the volume control on the selected navigation radio unit volume control. SPKR PA TEST Pressing SPKR selects the aircraft radios over the cabin speaker, if fitted. The speaker output is muted when a COM microphone is keyed. Adjustment of the GMA 340 speaker output level is completed by the installing agency. The PA mode is activated by pressing the PA button. Then, when either the pilot s or copilot s microphone is keyed, the corresponding mic audio is heard over the cabin speaker, if fitted. If the SPKR button is also active, then any selected audio is muted while the microphone is keyed. The SPKR button does not have to be previously active in order to use the PA function. Pilot and copilot microphone speaker levels are adjustable by the installing agency. Pressing the TEST button allows the function of the enunciator lights to be checked. All lights should illuminate when the TEST button is pressed. NOTE Technical assistance should be sought if an enunciator light fails to illuminate. ICS ISOLATION The GMA 340 provides three intercom modes: PILOT, CREW and ALL. Mode selections accomplished using the PILOT and/or CREW buttons. Pressing a mode button activates the corresponding ICS mode. Pressing again deactivates the mode. The ALL mode is active when neither PILOT nor CREW LEDs are lit. To switch from PILOT to CREW mode press the CREW button; from CREW to PILOT press the PILOT button. An LED ON indicates the isolation is active. Pushing the PILOT button isolates the pilot from everyone else and dedicates the aircraft radios to the pilot exclusively. The copilot and passengers share communications between themselves but cannot communicate with the pilot or hear the aircraft radios. DATE ISSUED: 1 December 2003 9-2-5
Pushing the CREW button places the pilot and copilot on a common ICS communication channel with the aircraft radios. The passengers are on their own intercom channel and can communicate with each other, but cannot communicate with the crew or hear the aircraft radios. With neither the PILOT or CREW button selected the pilot, copilot and passengers are able to communicate with one another on the ICS and listen to all radios. MUSIC1 and MUSIC2 stereo entertainment inputs are affected by the intercom mode selection. MODE PILOT (LED LIT) CREW (LED LIT) ALL (LEDS OFF) PILOT HEARS MUSIC1 Passengers MUSIC1 COPILOT HEARS Passengers. MUSIC1. MUSIC1. Passengers MUSIC1 PASSENGER HEARS Passengers. MUSIC1. Passengers. MUSIC2. Passengers MUSIC1 MUSIC 1 MUTING TRIGGERED BY Copilot or passenger intercom activity. Aircraft radio activity. MKR activity. Pilot or copilot activity. Aircraft radio activity. MKR activity. Intercom activity LIGHTING LED button enunciator and marker beacon lamp intensity are controlled automatically by built-in photocell on the front panel. Nomenclature backlighting is controlled by the aircraft dimmer bus. AUXILLARY ENTERTAINMENT INPUTS The GMA 340 provides two stereo entertainment inputs: MUSIC1 and MUSIC2. MUSIC1 is soft muted during all aircraft radio activity and normally during ICS activity. MUSIC2 is a non muted input. These inputs are compatible with popular portable equipment devices such as cassette tape or CD players. The headphone outputs of these devices are used and plugged into MUSIC1or MUSIC2. Two 3.5mm stereo phone 9-2-6 DATE ISSUED: 1 December 2003
jacks should be installed in a convenient location for this purpose. MUSIC1 and MUSIC2 have characteristics that are affected by the active intercom mode. SECTION 2 LIMITATIONS There is no change to the airplane limitations when the Garmin GMA 340 Audio Panel is installed. SECTION 3 EMERGENCY PROCEDURES There is no change to the airplane emergency procedures when the Garmin GMA 340 Audio Panel is fitted. AUDIO PANEL OPERATIONS SECTION 4 NORMAL PROCEDURES 1. PILOT Selector Knob ROTATE smaller knob to turn unit on 2. TEST Button PRESS to verify all lights operational 3. COM/MIC Button PUSH required transceiver button (COM 1 MIC, COM 2 MIC OR COM 3 MIC) 4. COM Button PRESS required audio selector buttons. 5. PILOT Selector Knob Rotate smaller knob to adjust Intercom System volume 6. COPILOT Selector Knob Rotate smaller knob to adjust Intercom System volume 7 PILOT Selector Knob ROTATE larger knob to adjust Voice Activated Intercom Squelch level. DATE ISSUED: 1 December 2003 9-2-7
8. COPILOT Selector Knob ROTATE larger knob to adjust Voice Activated Intercom Squelch level. NOTE When the microphone is keyed the active transceiver s MIC button LED blinks approximately once per second to indicate that the radio is transmitting. MARKER BEACON OPERATIONS 1. PILOT Selector Knob ROTATE smaller knob to turn unit on 2. TEST Button PRESS to verify all lights operational 3. SENS Button PRESS to select HI or LO sensitivity. 4. MKR/Mute Button PRESS to select required marker audio. SECTION 5 PERFORMANCE There is no change to the airplane performance when the Garmin GMA 340 audio panel is fitted in the instrument panel. 9-2-8 DATE ISSUED: 1 December 2003