GENERAL Failure conditions are processed by an Integrated Alerting Unit (IAU) for visual and aural presentation to the pilots. Pre-stall warning and ground proximity warning are not integrated. The IAU classifies the alerts in three levels according to urgency and/or priority of the required action: Level 3 This alert level requires immediate corrective or compensatory action by the crew. The presentation comprises a repetitive triple chime, two flashing red Master Warning Lights (MWL), and the relevant red light at the Central Annunciator Panel (CAP). Any engine related level 3 alert is accompanied by an IAU produced white light in the relevant FUEL lever. Engine fire is additionally annunciated at the ENGINE FIRE panel. Level 2 This alert level requires immediate crew awareness and subsequent corrective or compensatory action. The presentation comprises a double chime, two flashing amber Master Caution Lights (MCL), and the relevant amber lights at the CAP and/or the relevant local panel. Level 1 This alert level requires crew awareness and may require action. The presentation comprises a single chime and the relevant amber lights at the overhead panel. Level 1 alerts are not annunciated by MWL or MCL. Next to the levels described above, the IAU produces three dedicated alerts, which are presented aurally only. The alerting system characteristics are based on the general concept that under routine operation, all annunciators lights are off. Aircraft system alerts are presented in the relevant section. Page 1
VISUAL ALERTS Master Warning and Master Caution Lights Neither MWL s nor MCL s can be dimmed. MWL s and MCL s are cancelled when the fault is corrected or when the relevant master light is depressed by either pilot. Two level 3 annunciations cannot be cancelled by depressing MWL: The landing gear not down with landing flap position alert. The take-off configuration warning. CAP and local lights The nature and/or location of a failure is presented by lights at the CAP and/or local panel. The lights are cancelled when the fault is corrected. Corrective action to a fault which is presented by a light integrated with a pushbutton is accomplished by depressing that pushbutton. Local lights are located at the overhead panel, except the landing gear lights, which are located at the center main instrument panel. The CAP is also located at the center main instrument panel. Dimming All visual alerts, except MWL and MCL, have two brightness levels: bright and dim. A brightness selector is located at the flight deck lighting panel. Any new level 3 or 2 alert is presented bright, irrespective of the position of the brightness selector. After depressing the relevant master light, the light reverts to the selected level. Level 1 lights illuminate bright or dim, as selected. When electrical power is applied to the system, annunciator lights illuminate bright, irrespective of the position of the brightness selector. Brightness control is now available after momentarily selecting the reset position. Page 2
AURAL ALERTS Identification All aural alerts are integrated in the aircraft audio system. Aural alerts for level 3, 2 and 1 are attention getting chimes; they identify the level of urgency. The repetitive triple chime, which annunciates a level 3 alert, is cancelled when the fault is corrected of when either MWL is depressed. The repetitive chime due to landing gear not down with landing flap position, or due to an unsafe take-off configuration cannot be cancelled by depressing either MWL. In addition to the chimes, the IAU provides the following dedicated aural alerts: Cavalry charge: Autopilot disengagement Clacker: Aircraft overspeed C chord: Altitude entry Buzzer: Pilot call For aircraft equipped with selcal Interrupted Buzzer Selcal The dedicated aural alerts cannot be cancelled by depressing either master light. Priority Aural alerts are presented in the following order of descending priority: 1. Cavalry charge 2. Clacker 3. Repetitive triple chime (+MWL) 4. C -chord 5. Double chime (+MCL) 6. Buzzer 7. Interrupted buzzer (only for selcal equipped aircraft) 8. Single chime An aural alert in progress is interrupted when an alert of a higher priority is to be generated. When the overruling alert is cancelled, the interrupted alert is presented again. Local lights and CAP lights are not subject to priority. Warning audio inhibition All aural alerts can be inhibited by depressing the WARN AUDIO pushbutton at the general switching panel. The pushbutton, which should be operated only to prevent aural nuisance during emergency landings, is guarded. Page 3
INHIBIT MODES General Alerts that are not desired during take-off and in an engine-out condition are inhibited. The INHIB/CANC pushbutton at the CAP annunciates INHIBIT when the IAU is in either of these inhibit modes. The inhibit function can be cancelled by depressing this pushbutton. The system inhibits also consequential alerts, e.g. alerts following an intentional action such as engine shut down. Take-off inhibit mode During take-off, engine fire alerts, engine failure alerts and engine oil low pressure alerts are not inhibited. All other alerts are inhibited. The take-off inhibit mode is valid above 80 knots. The take-off inhibit mode ends approximately 40 seconds after lift-off, except for an attitude disagreement between LH and RH EFIS which can be presented immediately after lift-off. In case the take-off is rejected, the take-off inhibit mode is cancelled when the POWER levers are retarded. Engine out inhibit mode Engine related failure conditions, such as a low bleed-air pressure or generator failure, are not presented when the propeller speed of the engine is below ground idle. Engine fire and engine failure alerts are not inhibited. An engine failure alert is presented when the HP-spool speed or the torque is below a preset limit. SYSTEM OPERATION The integrated alerting system can operate normally with battery power only. Failures The IAU has two separate processing channels. A failure of one channel, annunciated by an ALERT SYS CHAN FAIL light at the AVIONICS panel, will not affect system operation. When the system fails completely, a FAULT light in the ALERT SYST pushbutton, located at the CAP, illuminates bright and the system reverts to the backup mode automatically. Backup mode The backup mode is obtained either automatically (FAULT) or manually (BACKUP). Manual selection of BACKUP is possible by depressing the ALERT SYST pushbutton. In case of a complete IAU failure, only CAP lights and two dedicated aural alerts are available. These aural alerts are: Cavalry charge in case of an automatic autopilot disengagement Clacker in case of an aircraft overspeed Local lights, MWL, MCL, buzzer, and chimes are not available. Page 4
SYSTEM TEST Test sequence A system test is initiated by depressing the ALERT SYS TEST pushbutton at the test panel. A light, integrated in the pushbutton, indicates TEST in progress. The test, which is controlled by the IAU, comprises an automatic backup test and an alert-light filament test. Completion of the test, with or without faults, is annunciated by a chime. When a fault is detected the TEST light remains illuminated. When no failures are detected, a green CMPL (completed) light illuminates and the TEST light goes out. Normal system operation is resumed automatically 30 seconds after the chime, or manually when the ALERT SYS TEST pushbutton is reset. Automatic backup failure If during the first few seconds of the test, the FAULT light in the ALERT SYST pushbutton at the CAP does not illuminate, automatic backup fails. When the light does illuminate, indicating that the system is in the backup mode, several other lights at the CAP may illuminate additionally. Filament failure All IAU related red and amber lights in the flight deck, plus 2 white fuel lever lights are tested. Each light has two filaments. After completion of the test, a single filament failure is indicated by flashing of the other filament. When both filaments in one light fail, all other IAU controlled lights illuminate. Page 5
FUNCTIONAL DIAGRAM Page 6
CONTROLS AND INDICATORS Page 7
A Central annunciator panel - Type I L ENG OUT TO CONF R ENG OUT L ENG FIRE APU FIRE R ENG FIRE L ENG ITT L ENG OIL PR L BAT OVHT SMK FWD CARGO SMK AFT CARGO LG R ENG ITT R ENG OIL PR R BAT OVHT CABIN ALT AC SUPPLY SMK TOILET CAP LIGHTS (RED) Annunciate distinctive level 3 alerts COMPARE ATT ERP L ENG EC FLAP ASYM R ENG EC L PROP EC FLAP R PROP EC L ENG A-ICE ALT ALERT SKID CTL PITOT HEAT HYDR SYST R ENG A-ICE DOORS PAX DOOR AFT DOORS FWD DOOR ALERT SYST FAULT BACKUP INHIB CANC INHIBIT CANCEL CAP LIGHTS (WHITE) These lights are not part of the integrated alerting system. INHIBIT/CANCEL PUSHBUTTON Normal (blank) Inhibit function armed. INHIBIT (blue) System in inhibit mode. CANCEL (white) Inhibit function cancelled. ALERT SYSTEM PUSHBUTTON Normal (blank) All alerts controlled by the IAU. FAULT (amber) Complete IAU failure. System in backup mode. BACKUP (white) Backup mode selected. IAU bypassed. Page 8
A Central annunciator panel - Type II L ENG OUT TO CONF R ENG OUT L ENG FIRE R ENG FIRE L ENG ITT SMK FWD CARGO R ENG ITT L ENG OIL PR SMK AFT CARGO R ENG OIL PR L BAT R BAT OVHT LG OVHT CABIN ALT AC SUPPLY SMK TOILET CAP LIGHTS (RED) Annunciate distinctive level 3 alerts ERP COMPARE ATT L ENG EC FLAP ASYM R ENG EC L PROP EC FLAP R PROP EC L ENG A-ICE SKID CTL PITOT HEAT R ENG A-ICE ALT ALERT HYDR SYST DOORS PAX DOOR AFT DOORS FWD CARGO ALERT SYST FAULT BACKUP INHIB CANC INHIBIT CANCEL CAP LIGHTS (AMBER) Annunciate distinctive level 2 alerts CAP LIGHTS (WHITE) These lights are not part of the integrated alerting system. INHIBIT/CANCEL PUSHBUTTON Normal (blank) Inhibit function armed. INHIBIT (blue) System in inhibit mode. CANCEL (white) Inhibit function cancelled. ALERT SYSTEM PUSHBUTTON Normal (blank) All alerts controlled by the IAU. FAULT (amber) Complete IAU failure. System in backup mode. BACKUP (white) Backup mode selected. IAU bypassed. Page 9
A Central annunciator panel - Type III L ENG OUT TO CONF R ENG OUT L ENG FIRE APU FIRE R ENG FIRE L ENG ITT SMK FWD CARGO R ENG ITT L ENG OIL PR SMK AFT CARGO R ENG OIL PR L BAT R BAT LG OVHT OVHT CABIN ALT AC SUPPLY SMK TOILET DOORS ASC COMPARE ATT ERP L ENG EC FLAP ASYM R ENG EC L PROP EC FLAP R PROP EC L ENG A-ICE SKID CTL R ENG A-ICE L ENG TRQ PITOT HEAT R ENG TRQ ALT ALERT HYDR SYST DOORS PAX DOOR AFT DOORS FWD CARGO ALERT SYST FAULT BACKUP INHIB CANC INHIBIT CANCEL CAP LIGHTS (RED) Annunciate distinctive level 3 alerts CAP LIGHTS (AMBER) Annunciate distinctive level 2 alerts DOORS light is NOT connected. CAP LIGHTS (WHITE) ASC is NOT connected These lights are not part of the integrated alerting system. INHIBIT/CANCEL PUSHBUTTON Normal (blank) Inhibit function armed. INHIBIT (blue) System in inhibit mode. CANCEL (white) Inhibit function cancelled. ALERT SYSTEM PUSHBUTTON Normal (blank) All alerts controlled by the IAU. FAULT (amber) Complete IAU failure. System in backup mode. BACKUP (white) Backup mode selected. IAU bypassed. Page 10
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ALERTS CONDITION(S) / LEVEL AURAL MWL/MCL CAP LOCAL SINGLE IAU CHANNEL FAILURE 1 ALERT SYS CHAN FAIL CONDITION(S) / LEVEL AURAL MWL/MCL CAP LOCAL COMPLETE IAU FAILURE - FAULT ALERT SYST Page 14