Repaso Semana 3 ATA 26

What conditions do the fire protection systems monitor on the airplane?. Fire, smoke and cabin differential pressure only. Fire, smoke, engine overheat and pneumatic duct leaks. Nacelle temperature, oil pressure and bottle integrity. Engine vibration, hydraulic temperature and smoke.

Which statement correctly lists the fixed fire-extinguishing systems installed on the airplane?. Engines, APU, DLODS zones and lower cargo only. Cargo compartments, lavatories, MEC and APU only. Engines, lavatory waste, LLAR modules, APU, lower cargo and portables. Engines, APU, wheel wells and portable extinguishers only.

How many fire detection loops are installed on each engine?. Four discrete element loops linked in series. Three separate loops for core, fan and gearbox. One continuous loop covering all zones. Two independent loops designated loop 1 and loop 2.

Where are the engine fire detection cards physically located?. On the P5 overhead panel next to the test switch. On the P8 fire-control panel in the flight deck. In the MEC System Card File. Mounted inside each respective engine nacelle.

In normal dual-loop operation, when do fire or overheat indications appear on the flight deck?. Automatically every five minutes during continuous BIT. When one loop fails and the remaining loop is normal. Only when both loops simultaneously detect the condition. As soon as either loop detects the abnormal condition.

What occurs when a single fire-detection loop fails?. Only an advisory message appears; dual-loop logic continues. The associated fire bottle is automatically discharged. The entire detection system for that engine is inhibited. A status message is displayed and the system reverts to single-loop operation.

What is the basic construction of an engine fire-detector element?. A sealed photoelectric optical sensing chamber. A bimetallic thermal switch with fixed set-points. A pair of simple thermocouples wired in parallel. An Inconel tube filled with thermistor core material and two conductors.

As the temperature of the thermistor core increases, what happens to its electrical resistance?. Resistance increases in direct proportion to temperature. Resistance oscillates rapidly between two fixed values. Resistance remains essentially constant until the fire set-point. Resistance decreases as temperature rises.

What time delay is applied by the card before an overheat indication is generated?. No intentional delay is applied to overheat signals. A fixed delay of 15 seconds. A fixed delay of 7.2 seconds. A fixed delay of approximately 2 seconds.

How does the fire-detection card distinguish an electrical short from a genuine fire?. By comparing the final absolute resistance value reached. By measuring the rate of resistance change (a short falls much faster). By comparing the average nacelle temperature against a stored table. The card has no means of distinguishing the two conditions.

When a fire is detected, what does Alarm 1 from the fire-detection card supply?. An EICAS advisory message that appears on the primary displays. The fire-warning aural signal to the warning electronics unit. A ground path for the fire-switch unlocking solenoid and the fire-warning lights. A discrete signal sent only to the AIMS cabinets.

Which set of indications is presented for an engine overheat condition?. Engine fire-warning lights on the fuel-control switch only. A status message only, with no aural or master light. Master Caution lights, caution aural and an OVERHEAT ENG EICAS message. Master Warning lights together with the fire-warning aural.

13. Which set of indications is presented for an engine fire?. Caution aural together with a status message only. An advisory message with no master light or aural. Master Warning, fire aural, FIRE ENG message and both fire-warning lights. Master Caution lights and caution aural only.

What happens if both fire-detection loops on one engine fail?. The system continues to operate in single-loop mode using residual data. Advisory and status messages appear and detection for that engine becomes inoperative. Both fire bottles are discharged automatically as a precaution. No flight-deck message is generated until the next power cycle.

What is the primary purpose of the FIRE/OVHT TEST switch located on the P5 panel?. To clear and reset any latched EICAS warning or caution messages. To command a remote shutdown of the APU from the flight deck. To arm and discharge the engine and APU fire bottles. To initiate a test of the detection systems; results appear on the Primary Display.

When does the Built-In Test perform a complete functional check of the engine fire-detection system?. Once at the beginning of each flight hour during normal cruise. Only when an actual fire or overheat condition is already present. Only when the crew selects the test switch manually. At power-up, after any power interrupt, and every 5 minutes of continuous operation.

Engine and APU fire-detection cards are physically interchangeable. How does a card determine its required function?. The cards are colour-coded and are not in fact interchangeable. Program pins in the cardfile that interface with the channel/slot selection logic. Manual software loading performed by the technician on the MAT. A small physical selector switch mounted on the face of the card.

What special handling requirement applies to the fire-detection cards?. The cards must remain electrically powered while being removed. They are ESDS devices and must be handled according to AMM Standard Practices. Only ordinary rubber insulating gloves need be worn. No special electrostatic precautions are required during handling.

Which additional overheat-detection system is installed only on airplanes with the RR Trent 800 engine?. Dedicated nacelle smoke-detection sensors. Oil-leak temperature sensors mounted on the gearbox. Fan-blade tip-clearance and vibration sensors. Turbine overheat detection that uses thermocouples on the IP turbine.

How does the RR Trent 800 turbine-overheat system ultimately generate flight-deck warnings?. The thermocouples send temperature data directly to the AIMS cabinets. An overheat condition causes automatic discharge of the engine fire bottles. A single thermocouple drives the fire-detection card without EEC involvement. Front and rear thermocouples feed the EEC; if limits are exceeded the EEC signals the fire-detection card.

Where are the turbine-overheat thermocouples physically located on the RR Trent 800?. In the exhaust nozzle just upstream of the plug. Inside the accessory gearbox housing. On the left side of the intermediate-pressure turbine casing (front and rear positions). Attached to the outer surface of the fan case.

Does the flight-deck FIRE/OVHT TEST switch also test the turbine-overheat detection system?. Only the EEC software portion of the system is tested. Only the forward thermocouple channel is tested. No, the FIRE/OVHT TEST switch does not test the turbine-overheat system. Yes, the test fully exercises both the thermocouples and the EEC interface.

What temperature information does the fire-detection card transmit to AIMS?. No temperature data is transmitted; only discrete fire/overheat flags are sent. The average temperature of the detection loops for use by the ACMS/ACMF. Temperature data from loop 1 only; loop 2 is used solely for fire logic. Only the highest instantaneous temperature recorded on either loop.

If one loop reports FIRE while the other loop remains NORMAL, what action does the card take?. It immediately forces the system into single-loop mode and waits. It simply ignores the FIRE report until both loops agree. It starts a 15-second timer, then tests the normal loop before deciding whether to alarm or deselect. It immediately declares a fire alarm without further checking.

How are the electrical terminals of the detector elements arranged to prevent crossed wiring?. The conductors are permanently soldered to the airplane wiring harness. Identical screw terminals are used at both ends of every element. The #10 terminal and the mating wire terminal have a black stripe. A #10 terminal is used at one end and a #8 terminal at the othe.

What extinguishing agent is contained inside the engine fire bottles?. Aqueous film-forming foam concentrate. A water-based fire-suppressant solution. Halon that is pressurized with nitrogen. High-pressure carbon dioxide gas.

How many engine fire bottles are installed and where are they located?. One bottle is mounted inside the horizontal-stabilizer compartment. Two bottles are located behind the right sidewall of the forward cargo compartment. Three bottles are installed in the main equipment centre. One bottle is mounted inside each engine nacelle.

Are the engine fire bottles interchangeable with the APU fire bottle?. They are interchangeable only with the lower-cargo bottles. Only the left-engine bottle is interchangeable with the APU bottle. No, each bottle is unique to its installation location. Yes, the engine bottles and the APU bottle are fully interchangeable.

What is the function of the squib fitted to a fire bottle?. It initiates the continuous BIT sequence of the detection system. It closes the isolation valves that protect the opposite engine. When electrically fired it ruptures a diaphragm and releases the agent under nitrogen pressure. It continuously measures and reports bottle internal pressure.

At what calendar interval must the squib of an engine fire bottle be replaced?. Every 10 years from the date stamped on the squib. There is no scheduled replacement life for the squib. At each scheduled engine overhaul interval. Every 5 years from the date of manufacture.

What happens when the engine fire switch is pulled to the OUT position?. No systems are affected until the switch is rotated to a DISCH position. The engine is shut down and isolated from airplane systems (fuel, hydraulics, generators, etc.). Only the fire-warning lights on the switch itself illuminate. Only the selected bottle is armed for subsequent discharge.

How is an engine fire bottle actually discharged after the switch has been pulled?. The discharge command is sent from the P40 ground-service panel. A push-button on the bottle itself is depressed by maintenance personnel. The switch is rotated to DISCH 1 or DISCH 2 and held for approximately one second. The bottle discharges automatically after a fixed time delay.

From which electrical bus does the engine-bottle discharge circuit obtain its power?. External ground-power only. The hot battery bus, which remains powered even with the battery switch OFF. The APU generator bus exclusively. The main DC bus that is powered only when generators are on-line.

What flight-deck indication is produced when the bottle pressure switch detects low pressure?. No flight-deck indication is generated for low bottle pressure. A precise numerical display of remaining agent quantity. A temperature-related caution message. Illumination of the associated discharge light plus advisory and status messages.

How often must the fire bottles undergo a hydrostatic pressure test?. At every annual inspection. Every 5 years from the date of the previous test. Every 10 years from the date of manufacture. Only after the bottle has been discharged in service.

What important precaution must be observed when handling fire-bottle squibs?. No special electrostatic or protective measures are required. Treat them as ESDS devices, fit protective covers, and never use a shunt plug. Ordinary insulating gloves are the only required protection. The circuit must be energized before the connector is disconnected.

What is the primary purpose of the APU fire-detection system?. To discharge the APU bottle on every fire indication without crew action. To measure and record APU-compartment temperature for the ACMS. To provide a visual alert to the flight crew only. To warn the crew or ground personnel and automatically shut down the APU if fire is detected.

How many distinct operating modes does the APU fire-detection system possess?. Four logic modes that change with flight phase. Three discrete modes selected by the ELMS. A single continuous mode that is always active. Two modes designated attended and unattended.

Under what airplane conditions does the APU fire-detection system operate in unattended mode?. Only when the APU itself has already been shut down by the crew. Continuously, irrespective of whether the airplane is on ground or in flight. On the ground with both engines not operating, as signalled by the ELMS. Whenever the airplane is airborne, regardless of engine status.

What detection logic is applied while the system is in attended mode?. Majority-vote logic that requires agreement of three sensors. Single-loop logic that ignores the second loop entirely. AND logic – both loops must detect fire before an alarm is generated. OR logic – either loop alone can generate an alarm.

What detection logic is applied while the system is in unattended mode?. No automatic logic is applied; only manual crew action is possible. AND logic identical to the attended mode. Strict dual-loop logic with no automatic discharge capability. OR logic (any single loop can cause an alarm) together with automatic bottle discharge.

How many fire detectors are installed in the APU compartment and what are their locations?. One detector mounted on the upper surface of the compartment. Two detectors mounted on the aft bulkhead of the compartment. Four detectors spaced equally around the APU casing. Three detectors located upper-forward, upper-aft and lower in the compartment.

Where is the APU fire-detection card installed?. On the P5 overhead panel beside the fire switch. In the P84 Right System Card File. In the P85 Left System Card File, slot A9. Inside the APU nacelle next to the detectors.

Which combination of indications appears in the flight deck when an APU fire is detected?. The ground-service horn only, with no flight-deck indication. A status message on EICAS with no master light or aural. A single red warning light on the APU control panel only. Master Warning, fire aural, EICAS FIRE APU message and the APU fire-switch light.

What indications are provided at the P40 nose-landing-gear service panel when an APU fire occurs on the ground?. A text message displayed on a small local screen. A steady red light with no audible warning. No indications are provided at the P40 panel. An intermittent horn together with an APU fire-warning light.

Does the APU shut down automatically when a fire is detected?. Only when the system is operating in attended mode. Only when the system is operating in unattended mode. Yes – the shutdown is commanded through the ELMS and the APU controller. No – the flight crew must always initiate the shutdown manually.

Where is the APU fire-extinguishing bottle physically installed?. Mounted inside the APU nacelle itself. Inside the main equipment centre. In the forward cargo compartment next to the engine bottles. On the left side of the horizontal-stabilizer compartment.

Under what conditions does the APU fire bottle discharge automatically?. The bottle never discharges automatically; crew action is always required. Only while the airplane is in flight and the APU is running. In unattended mode after a fire is detected, following a short time delay. On every fire indication, regardless of airplane status.

What sequence of events occurs when the APU fire switch is pulled to the OUT position?. The APU is started to provide additional fire-fighting airflow. No airplane systems are affected until the switch is rotated. The APU is shut down, the fuel shut-off valve closes and the bottle is armed. Only the bottle is armed; the APU continues to run.

What does the APU fire-shutdown switch on the external service panel accomplish?. It silences the ground horn without affecting the APU. It causes immediate discharge of the APU fire bottle. It shuts down the APU and closes the APU fuel shut-off valve. It only sounds the ground-service horn to alert personnel.

From which electrical source does the APU bottle squib receive its firing power?. External ground-power only. The APU generator bus exclusively. The 28 V DC hot battery bus. The main DC bus that is powered only when generators are on-line.

How many smoke detectors are installed in the lower cargo compartments?. No dedicated smoke detectors are fitted in the lower cargo holds. Three detectors distributed inside each compartment. A single detector that serves both forward and aft compartments. One detector in the forward compartment and one in the aft compartment.

What additional function is performed by the forward cargo smoke detector? A) C) D). It continuously performs BIT of the APU fire-detection system. It automatically discharges the cargo fire bottles when smoke is detected. It controls and supplies electrical power to the E/E-cooling smoke detector. It has no function beyond monitoring its own compartment.

What flight-deck indications accompany a lower-cargo smoke detection?. An advisory message that can be cancelled by the crew. A status message on EICAS with no master light or aural. EICAS cargo-fire warning, fire aural, master warning and the FWD or AFT cargo-fire light on P5. A single red light on the cargo-fire panel only.

Why are water separators and heaters installed in the cargo smoke-detection sampling lines?. They are installed for structural reasons and have no detection function. To increase the pressure of the sample airflow through the detector. To cool the sampled air before it reaches the optical chamber. To remove condensation and thereby reduce the likelihood of moisture-induced false alarms.

What types of extinguishing bottles are used in the lower-cargo fire-protection system?. Portable extinguishers that must be manually activated by the crew. Metered bottles that provide only a slow continuous discharge. Dump bottles that provide only a single rapid discharge. Dump bottles for rapid initial discharge plus metered bottles for controlled slow discharge.

What is the operational purpose of the dump bottles?. To measure and display the remaining quantity of extinguishing agent. They have no operational function and serve only as pressure reservoirs. To deliver a rapid discharge that knocks down the fire when the DISCH switch is selected. To provide a slow, continuous discharge that lasts for several hours.

What is the operational purpose of the metered bottles?. They serve solely as a backup pressure source for the dump bottles. They operate only while the airplane is on the ground. After a time delay they discharge slowly to maintain agent concentration for an extended period. To provide the initial rapid discharge that extinguishes the fire.

How does the flight crew select which lower-cargo compartment will receive the extinguishing agent?. By a maintenance page selection on the MAT only. By a command sent from the P40 ground-service panel. By arming either the FWD or the AFT switch on the cargo-fire panel. Selection is performed automatically by the smoke-detection logic.

What extinguishing agent is used in the lower-cargo fire bottles?. A dry-chemical powder formulation. A fine water-mist spray. High-pressure carbon dioxide. Halon 1301 that is pressurized with nitrogen.

What does the Duct Leak and Overheat Detection System (DLODS) monitor?. Temperature inside the APU compartment only. Temperature inside the main and nose wheel wells only. Pneumatic ducts and engine anti-ice ducts for leaks or overheat conditions. Smoke concentration inside the cargo compartments.

Which detectors form part of the complete DLODS installation?. Body-duct detectors only. Fan-case overheat detectors only. Wing leading-edge detectors only. Fan-case overheat, strut overheat, wing-duct-leak and body-duct-leak detectors.

What automatic actions occur when DLODS detects an overheat or duct-leak condition?. A status message only, with no master light or valve action. Immediate discharge of the nearest engine fire bottle. Master caution lights, an EICAS caution message and automatic closure of the related pneumatic isolation valves. No automatic action is taken; only a status message is displayed.

How many DLODS control cards are installed in the airplane?. Four cards, one for each major duct zone. Two cards, one left and one right. Three identical cards designated left, centre and right. A single central control card.

How are the main-wheel-well fire detectors electrically arranged?. No dedicated fire detectors are fitted in the main wheel wells. Three detectors are installed in each well and wired in a voting arrangement. Two adjacent detectors are fitted in each well; left and right detectors are paired to form two independent loops. One independent detector is installed in each main wheel well.

Which cards are responsible for monitoring the wheel-well fire detectors?. The AIMS cabinets receive the signals directly. The APU fire-detection card. The left and right DLODS control cards. The left and right engine fire-detection cards.

What flight-deck indication is generated when a fire is detected in a main wheel well?. An advisory message that can be cancelled by the crew. A status message with no aural or master light. A caution message with master-caution lights only. An EICAS warning message, the fire bell and the master-warning lights.

Where are the indications of a lavatory smoke condition presented?. Only on the flight-deck EICAS displays. Inside the affected lavatory, at the attendant stations (CMS/CSS) and on the flight-deck EICAS. Only on the P40 ground-service panel. Only on the AIMS maintenance pages accessible via the MAT.

Which cabin system is responsible for generating the lavatory-smoke indications (depending on airplane configuration)?. The Proximity Sensor Electronics Unit (PSEU) only. The Overhead Panel ARINC System (OPAS) only. The Cabin Management System (pre-SB) or Cabin Services System (post-SB), which drives the CSCP/CACP message, master-call light and chime. The Airplane Information Management System (AIMS) only.

Which airplane system automatically tests all of the fire-extinguishing squibs?. The Overhead Panel ARINC System (OPAS). The Electrical Load Management System (ELMS) at power-up and at engine shutdown on the ground. The Airplane Information Management System (AIMS). The Warning Electronics Unit (WEU).

What important electrical characteristic is shared by the engine and APU fire switches?. They are functional only while the airplane is in flight. They require external ground power to be connected before they can operate. They are connected to the hot battery bus, allowing bottle discharge even with the battery switch OFF and no external power. They are powered exclusively from the main DC bus that is available only when generators are on-line.

Are the left-engine, right-engine and APU fire switches interchangeable with one another?. Only the APU switch is unique; the two engine switches are identical. Only the two engine switches are interchangeable; the APU switch is unique. No – they differ in faceplate labels, electrical connectors and the orientation of the locating hole/peg. Yes, all three switches are fully interchangeable.

What is the purpose of the fire-override switch that is part of each fire-switch assembly?. To reset any latched warning or caution messages on the EICAS displays. To initiate a full system test of the detection and extinguishing circuits. To allow the fire switch to be pulled even when the unlocking solenoid is not energized. To command immediate discharge of the associated fire bottle.

After maintenance has been performed on a fire-detection system, what action is recommended before the airplane is released?. The system should be checked only on the Maintenance Access Terminal. The related fire bottles should be discharged and then recharged. No further functional check is required once the hardware is reinstalled. A FIRE/OVHT TEST should be performed to confirm that the system operates correctly.

What extinguishing agent is used in the majority of the fixed fire-protection systems (engines, APU and cargo)?. A dry-chemical powder formulation. A fine water-mist spray system. High-pressure carbon dioxide. Halon that is pressurized with nitrogen.