moduel 11E +fire

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Questions and Answers

What triggers the activation of the warning system in the Lindberg fire detection system?

Cooling of the sensing element

Depletion of the inert gas

Decrease in pressure within the tube

Rise in ambient temperature (correct)

How does the titanium wire function within the Systron-Donner system?

By sealing the tube at one end

As a conduit for electrical switches

As the gas absorption material (correct)

By enhancing gas pressure stability

What is the relationship between pressure and temperature in the Lindberg fire detection system?

There is no relationship between pressure and temperature

Pressure increases with rising temperatures (correct)

Pressure increases with lower temperatures

Pressure decreases when temperature rises

What is a distinguishing feature of the Systron-Donner pneumatic system compared to the Lindberg system?

Utilization of helium gas Signup and view all the answers

In the inspection and maintenance of the Lindberg system, which component is primarily tested?

The control unit wiring Signup and view all the answers

What component of the Systron-Donner system is responsible for maintaining closed switch contacts?

Gas pressure in the tube Signup and view all the answers

What is the primary purpose of a smoke-detection system in aircraft?

To detect the presence of smoke indicating a fire Signup and view all the answers

What is the primary function of the change in electric current flow within a smoke detection system?

To trigger a warning indication Signup and view all the answers

Which type of smoke detector system uses light reflection to detect smoke?

Photoelectric type Signup and view all the answers

At what smoke concentration level does the photoelectric cell start reflecting light to indicate a warning?

10% Signup and view all the answers

How does the photoelectric smoke detector amplify the output signal?

With a built-in amplifier circuit Signup and view all the answers

Which type of fire condition does the smoke detection system primarily respond to?

Smoldering fires producing smoke Signup and view all the answers

What components are connected to the 'VENTURI EJECTOR' in the smoke detection system?

AFT and bulk cargo compartment smoke detectors Signup and view all the answers

What type of gases can smoke detection systems monitor that may indicate a fire condition?

Carbon monoxide and nitrous oxides Signup and view all the answers

Under what condition does the alarm switch close in the Systron-Donner system?

When the temperature exceeds a pre-set level Signup and view all the answers

What occurs after a fire has been extinguished in the fire detection system?

The titanium wire absorbs hydrogen gas and breaks responder contacts Signup and view all the answers

Which of the following describes the configuration of fire detection loops to enhance system reliability?

Dual-loop configuration is utilized Signup and view all the answers

What happens if one loop fails in the dual-loop configuration?

The control box isolates the defective loop and reconfigures to single-loop operation Signup and view all the answers

What is the role of the integrity switch in the fire detection system?

To break the supply from the test switch if gas leaks occur Signup and view all the answers

Which material is primarily responsible for the fire warning function in the system?

Titanium wire Signup and view all the answers

What is a critical requirement for fire detection systems in aircraft?

They must operate independently of other systems. Signup and view all the answers

Where are detector units installed in an aircraft?

In locations where there are greater risks of a fire. Signup and view all the answers

Which indicator would show a fault in the overheat detection system?

FAULT indicator Signup and view all the answers

What type of indicator indicates whether the fire extinguishing bottles are discharged?

DISCHARGED indicator Signup and view all the answers

What is the function of fire warning systems in aircraft?

To alert the flight crew of a fire or overheat condition. Signup and view all the answers

What consequence might occur if a fire detection system fails?

It is more likely to be inoperative. Signup and view all the answers

Which system provides rapid detection of localized fire or overheat conditions?

Overheat detection systems. Signup and view all the answers

What is a potential cause of aircraft fires mentioned?

Faulty electrical devices. Signup and view all the answers

What visual indication is present on the flight deck during a fire situation?

Red master warning light Signup and view all the answers

What is the primary purpose of overheat warning systems in aircraft?

To warn of high temperature areas that may risk fire Signup and view all the answers

Which type of fire detection system is commonly found in older model aircraft?

Thermal switch system Signup and view all the answers

What happens when the thermal switch in a fire detection system detects heat?

It closes the contact points to allow current flow Signup and view all the answers

In the context of a fire detection alert, what does pressing the bell cancel button do?

Stops the warning bell from ringing Signup and view all the answers

Where are overheat warning systems typically installed in an aircraft?

In engine turbine areas and wheel wells Signup and view all the answers

What component completes the circuit for activating the warning light and bell in a thermal switch system?

Relay RL1 Signup and view all the answers

In modern aircraft, what is the primary advantage of using continuous-loop fire detection systems?

Greater coverage of fire hazards Signup and view all the answers

What happens to RL2 once the bell cancel button is released?

RL2 remains energized until the fire warning condition disappears. Signup and view all the answers

What is the purpose of the test switch in this system?

To complete a ground connection for continuity testing. Signup and view all the answers

What occurs when the temperature at the hot junction reaches a preset level?

A warning indication is activated. Signup and view all the answers

What is a potential consequence of installing a switch with a different operating temperature?

False warnings or no warnings during a fire. Signup and view all the answers

Which component in the thermocouple fire detection system is insulated from surrounding air?

Cold junction Signup and view all the answers

What relationship exists between temperature rise at the hot junction and current flow?

Current flow directly increases with the rate of temperature rise. Signup and view all the answers

How many active thermocouples are typically used in a thermocouple system around an engine?

Several, with a reference thermocouple. Signup and view all the answers

What key function does the 'BUS' serve in this system?

It provides power to all components. Signup and view all the answers

What is the role of the hot lead in the Kidde sensing system?

It provides a current signal based on temperature changes. Signup and view all the answers

What type of damage can potentially cause false alarms in a pneumatic continuous-loop system?

Mechanical damage to the sensor tube. Signup and view all the answers

What is the temperature range that activates the alarm switch for the averaging function in the pneumatic detector?

93 °C (200 °F) to 371 °C (700 °F) Signup and view all the answers

How is the discrete temperature sensing function activated in the pneumatic system?

By hydrogen gas outgassing from a heated section. Signup and view all the answers

What ensures the pneumatic system does not provide false alarms due to mechanical damage?

Design that causes a 'no test' indication for severe damage. Signup and view all the answers

What is the primary function of the helium gas in the pneumatic detector?

To activate the alarm switch based on average temperature. Signup and view all the answers

What happens when a section of the pneumatic detector tube heats up to the discrete temperature?

Hydrogen gas is released and pressure increases. Signup and view all the answers

What is a requirement for flight crew and maintenance crews regarding fire detection systems?

Perform an integrity test before each engine start. Signup and view all the answers

What principle underlies fire safety methods?

Separating fuel sources and ignition sources Signup and view all the answers

Which fire extinguishing agent is commonly used in aircraft fire suppression systems?

Halon 1301 Signup and view all the answers

What feature indicates that an extinguishing agent has been discharged normally from an HRD container?

A yellow indicator disc Signup and view all the answers

Which components do High-Rate-of-Discharge systems commonly utilize for fire extinguishing?

Halogenated hydrocarbons and perforated tubing Signup and view all the answers

How is pressure maintained within the HRD fire extinguisher containers?

By pressurizing with dry nitrogen Signup and view all the answers

Which area of an aircraft is typically equipped with fixed fire-extinguishing systems?

Cargo holds Signup and view all the answers

What action is triggered when a bottle in an HRD system is subjected to high temperatures?

The system vents the extinguishing agent Signup and view all the answers

What components typically comprise the operating mechanism of HRD fire-extinguishing systems?

Electrically ignited discharge cartridges and strainer assemblies Signup and view all the answers

What is the main purpose of the aircraft smoke-detection system?

To sample the cabin air for the presence of smoke Signup and view all the answers

Which component of the smoke detection system triggers a warning when smoke is detected?

The smoke detector's photocell Signup and view all the answers

What type of smoke detection system relies on light refraction to detect smoke?

Photoelectric system Signup and view all the answers

At what smoke concentration level does the photoelectric cell begin to indicate a warning?

10% Signup and view all the answers

Which gases can the smoke detection system monitor that indicate a potential fire condition?

Carbon monoxide and nitrous oxides Signup and view all the answers

What happens when smoke is detected by the smoke detection system?

An alert is sent to the flight crew Signup and view all the answers

In a refraction photoelectric system, what occurs when smoke enters the detection chamber?

Light is refracted to a photocell Signup and view all the answers

What is the effect of smoke presence on the electric current flow in the smoke detection system?

It causes the current to change, triggering a warning Signup and view all the answers

What is the primary function of a Ram Air Turbine (RAT) in large aircraft?

To supply hydraulic power for flight controls when both engines fail Signup and view all the answers

Which type of generator is commonly used in emergency situations on aircraft?

Permanent magnet alternators Signup and view all the answers

In a hydraulic electrical generating system (HEGS), what is the role of the Generator Control Unit?

To control the AC generator Signup and view all the answers

What type of electrical output does the AC generator produce in the emergency AC generation system?

Three-phase 115-V AC at 400 Hz Signup and view all the answers

What happens when both engine-driven generators fail in an aircraft's emergency system?

The hydraulic motor-driven generator operates automatically Signup and view all the answers

What supplies hydraulic power to the hydraulic constant speed motor in the emergency power system?

Main hydraulic system or RAT pump Signup and view all the answers

How does the Hydraulic Constant Speed Motor (CSM) contribute to the emergency generation system?

It drives the AC generator when main power is lost Signup and view all the answers

What voltage and frequency is supplied by the emergency power system to the essential buses?

115 V at 400 Hz Signup and view all the answers

What is the primary purpose of the voltage regulator in aircraft generators?

To maintain a fixed output voltage under varying load conditions Signup and view all the answers

How does a rheostat control the voltage output of a generator?

By altering the strength of the magnetic field through field current adjustment Signup and view all the answers

What occurs when the AC ESS bus shed network is isolated in battery-only configuration?

The DC essential bus remains operational Signup and view all the answers

What role do the essential shed bus contactors play in electrical systems during emergencies?

They isolate essential buses from power loss Signup and view all the answers

What determines the voltage output of an aircraft generator besides the field current?

The load conditions on the generator Signup and view all the answers

In an emergency hydraulic pump scenario, what role does the RAT pump play?

It provides hydraulic pressure to essential bus supply contactors Signup and view all the answers

What typical output voltage is regulated for aircraft DC generators?

28-V DC for most aircraft and 14-V DC for light aircraft Signup and view all the answers

What is a consequence of setting the rheostat to increase resistance in the field coil circuit?

Less magnetism is induced in the armature Signup and view all the answers

What is the primary purpose of the DC power generation system in an aircraft?

To provide electrical power for the aircraft's critical systems. Signup and view all the answers

How does an aircraft's emergency power generation system function during a power failure?

It provides a secondary power source to maintain essential systems. Signup and view all the answers

What is the role of voltage regulation in an aircraft's electrical system?

To maintain constant voltage levels regardless of load changes. Signup and view all the answers

What is the primary function of inverters in an aircraft electrical system?

To convert DC to AC power. Signup and view all the answers

What happens to the aircraft's metallic structure in a negative-ground electrical system?

It becomes negatively charged, creating a potential difference. Signup and view all the answers

Which component is essential for protecting an aeroplane's electrical circuits from overload?

Circuit breakers Signup and view all the answers

What role does the surge quench diode play in an alternator's regulator?

It prevents damage to the transistor by shorting induced current. Signup and view all the answers

What is the significance of the aircraft maintenance manual concerning electrical systems?

It outlines the standard practices for electrical repairs and troubleshooting. Signup and view all the answers

What is the purpose of an aircraft's external power supply connection?

To supply power for operations when the main systems are offline. Signup and view all the answers

Which component is responsible for converting the alternating current from the exciter into direct current?

The rotating rectifier. Signup and view all the answers

What happens when transistor T1 switches off the field current in an alternator?

A magnetic field is induced in the field coil. Signup and view all the answers

In what situation might a light twin engine aircraft require an alternate regulator?

If the first regulator fails. Signup and view all the answers

What is the purpose of the exciter field in a brushless alternator?

To induce alternating current into the exciter armature. Signup and view all the answers

How does the main generator armature produce voltage?

Through the induction of AC voltage from the main field. Signup and view all the answers

What condition leads to the diode in the regulator conducting?

When the field current is switched off and the magnetic field collapses. Signup and view all the answers

What type of voltage does the main generator's armature windings produce across one phase?

115 volts. Signup and view all the answers

What happens when one of the generators becomes inoperative?

Power is supplied via the auxiliary contacts of the tripped GCB to the BTB. Signup and view all the answers

What occurs when both generators become inoperative?

The essential bus switches to battery backup through the BTB. Signup and view all the answers

What is the role of the changeover relay under normal conditions?

To connect the essential bus to the no. 1 generator bus. Signup and view all the answers

Why are the normal, essential, and emergency buses separated from each other?

To ensure redundancy and flight safety during power malfunctions. Signup and view all the answers

What happens to the battery relay if the system operates under emergency conditions for too long?

It isolates the aircraft’s AC and DC essential loads from power. Signup and view all the answers

In what scenario would the essential AC loads be supplied by a static inverter?

When both GCBs trip due to generator failure. Signup and view all the answers

What is one key difference between relays and contactors?

Relays are typically used for low-current switching applications. Signup and view all the answers

What is a consequence of operating the system with both generators offline?

Essential loads receive power only from the battery. Signup and view all the answers

What is the primary purpose of a transformer in an AC electrical system?

To change voltage and current values using mutual inductance Signup and view all the answers

What happens to the current in the secondary coil of a transformer if the voltage is increased by a 1:10 ratio?

The current decreases by a 10:1 ratio Signup and view all the answers

What is the turns ratio of a transformer with 100 turns in the primary coil and 1000 turns in the secondary coil?

1:10 Signup and view all the answers

Which scenario illustrates how a transformer can block line voltage when the secondary coil is open-circuited?

The back voltage in the primary coil opposes the source voltage Signup and view all the answers

Which statement about transformers is correct regarding their construction?

Transformers consist of two coils wound around a common core Signup and view all the answers

What is a consequence of increasing voltage in a transformer?

Current must decrease correspondingly Signup and view all the answers

What distinguishes transformers with multiple secondaries or tappings?

They allow for either higher or lower voltage outputs Signup and view all the answers

How do transformers handle power in the secondary coil when there is an increase in primary voltage?

Power in the secondary is the same as in the primary, minus losses Signup and view all the answers

Study Notes

Fire Detection Systems

Lindberg System:
- Utilizes a stainless-steel tube filled with inert gas and a gas-absorbing material.
- When heat is detected, the material releases gas, increasing tube pressure and activating a warning system.
- Tested using a low-voltage AC current to release gas and activate the warning system.
- The test confirms the integrity of the control unit, wiring, and detector element.
Systron-Donner System:
- Employs a stainless-steel tube filled with helium gas and a titanium wire acting as the gas-absorbing material.
- An increase in tube temperature releases hydrogen from the wire, triggering the alarm system.
- The system uses a dual-loop configuration for increased reliability, both loops need to sense a fire before the alarm sounds.
- If one loop fails, the system isolates the defective loop and continues with single-loop operation.

Overheat Detection System

Uses a variety of detector switches for different temperature ranges.
For example, "HP AIR DUCT O/HEAT DETECTOR SWITCH" is set to 350° ±15°C.

Smoke Detection Systems

Functionality:
- Samples cabin air for smoke, indicating a potential fire condition.
- Used in cargo compartments, equipment bays, and lavatories.
- Detects the presence of carbon monoxide (CO) and nitrous oxides as early warning signs.
- Smoke detection system triggers a warning indication when a change in electrical current flow is detected.
Types of Smoke Detectors:
- Photoelectric (comparison and refraction types)
- Ionisation type.
Refraction Photoelectric Systems:
- Air passes through a chamber.
- A pilot lamp illuminates the photocell, decreasing circuit resistance and activating the warning system.
- Smoke entering the chamber at a concentration of about 10% reflects light onto the photo diode and the photoelectric cell.
- The photoelectric cell output is amplified to trigger a warning device.
- A small test light illuminates the photoelectric cell to activate the system for testing.

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Description

This quiz covers various fire detection systems, including the Lindberg and Systron-Donner systems. Explore their mechanisms, testing methods, and reliability features. Understand the technology behind these crucial safety systems in fire management.