Aircraft Fuel Quantity Systems Overview

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

How many MLIs are present in each INNER tank?

4 (correct)

What should be done to check the total fuel quantity on the aircraft?

Use the MLI in the CENTER tank only

Divide the readings from the INNER tanks

Add the quantities from the CENTER, INNER, and OUTER tanks (correct)

Only check the OUTER tank MLI reading

What is indicated by the G7508471 - G7UT0TU - FM28B1000000003 code?

Manufacturer's warranty information

MLI serial numbers (correct)

Aircraft maintenance record

Fuel quantity measurements

Which function must be used to access roll and pitch data from the ADIRU?

CALL UP PARAM ALPHA Signup and view all the answers

To determine the volume of fuel for odd-numbered MLIs, what method is used?

Calculate the difference and interpolate Signup and view all the answers

What type of correction may be applied to the INNER tank volume?

Correction based on collector cell time since pump shutdown Signup and view all the answers

What is the correct procedure to use the MLI for checking fuel levels?

Extend the indicator rod and read the UNITS mark Signup and view all the answers

What is the attitude reading for the RIGHT wing MLI number - 6?

-1,0 for P and 0,5 for R Signup and view all the answers

What action does the FCMC take when an inner tank low level sensor becomes dry?

It stops the jettison operation if selected. Signup and view all the answers

At what low level quantity does the inner tank trigger the FCMC action?

1600 kg Signup and view all the answers

From where do the FCMCs receive fuel data?

From different probes. Signup and view all the answers

What information do both FCMCs also receive besides fuel data?

THS position from Flight Control Data Concentrators. Signup and view all the answers

What environmental factors do the Air Data and Inertial Reference Units (ADIRUs) provide to the FCMC?

Aircraft attitude, acceleration, and pitch and roll angles. Signup and view all the answers

What is not directly monitored by the FCMCs?

Air pressure. Signup and view all the answers

Which aircraft models are mentioned in the context of FCMC operations?

A330-200/300 Signup and view all the answers

What is the primary purpose of the FCMC in relation to fuel management?

To control and monitor fuel tank levels. Signup and view all the answers

What is the main function of the COM and MON processors in each FCMC?

To provide reliable fuel quantity and temperature measurements Signup and view all the answers

How do the COM and MON processors determine the usable fuel quantity?

By using capacitance values from FQI probes and permittivity Signup and view all the answers

What role does the independent level sensing board in each FCMC play?

It collects level sensing data for command calculation and warnings Signup and view all the answers

What data is accessed through the FUEL QUANTITIES menu?

Fuel quantities from any fuel tank Signup and view all the answers

What is the significance of the FCMC's cross-wired discretes?

They enable one FCMC to receive the level sensing status from the other Signup and view all the answers

Which parameter is NOT included in the INPUT PARAMETERS menu?

Ambient temperature Signup and view all the answers

What additional functions does each FCMC provide apart from measuring fuel quantity?

Integrity checking through various computations Signup and view all the answers

In what way do COM and MON processors differ in function?

They operate under different software but perform identical calculations Signup and view all the answers

What action does the FCMC take when the center tank low level sensor is dry?

Stops the operation of the center tank transfer pumps Signup and view all the answers

What is the function of the overflow sensor in the fuel system?

To monitor filling levels during refueling Signup and view all the answers

Which of the following sensors is NOT explicitly mentioned in connection with the fuel level sensing?

Temperature sensors Signup and view all the answers

What happens when the trim tank low level sensor indicates a dry condition?

The FCMC closes the trim tank isolation valve Signup and view all the answers

When does the FCMC trigger an ECAM warning?

When an overflow sensor becomes wet Signup and view all the answers

Which of the following describes the purpose of the ETOPS sensors?

To provide optional fuel level data Signup and view all the answers

What does the FCMC do when the overflow sensor becomes wet during refueling?

Closes all inlet valves and triggers an ECAM warning Signup and view all the answers

Which component is responsible for managing the transfer of fuel from the center tank?

FCMC Signup and view all the answers

What systems are included in the fuel tank indicating systems?

Fuel Quantity Indicating, tank level sensing, and temperature measurement Signup and view all the answers

What do the Fuel Control and Monitoring Computers (FCMCs) do with the data they receive?

They transmit the data to the ECAM FUEL page and the refuel/defuel control panel Signup and view all the answers

Which aircraft models are referenced in the context of fuel tank venting?

A330-200 and A330-300 Signup and view all the answers

What is the purpose of the fuel tank venting systems?

To maintain atmospheric pressure in the tanks Signup and view all the answers

When was the fuel tank venting document last revised?

November 20, 2008 Signup and view all the answers

Which component does NOT play a role in the fuel tank indicating systems?

Fuel pressure regulator Signup and view all the answers

What function does the ECAM FUEL page serve in the context of fuel management?

It provides real-time fuel status and alerts Signup and view all the answers

Which of the following statements regarding the refuel/defuel control panel is true?

It displays data from the FCMC and ECAM FUEL page Signup and view all the answers

What activates the APU pump in the event of low pressure in the trim transfer line?

The aft APU pump Signup and view all the answers

Which component closes in response to an APU fire detection?

APU LP valve Signup and view all the answers

What is the function of the fuel/air separator in the fuel transfer line?

To ensure sufficient fuel for APU operation Signup and view all the answers

What does the main transfer system primarily control?

Fuel flow from outer tanks to inner tanks Signup and view all the answers

What power sources can automatic refueling utilize?

Normal electrical power or battery power Signup and view all the answers

How does the APU fuel isolation valve operate?

It isolates fuel flow to the trim transfer line Signup and view all the answers

What is a significant role of the FCMC in managing fuel?

Collecting data on fuel quantity and transfer Signup and view all the answers

What does the fuel isolation valve primarily do?

Isolates fuel feeding to the APU Signup and view all the answers

Which function is NOT performed by the fuel system?

Pressure regulation in outer tanks Signup and view all the answers

What is the minimum tank content required for gravity purging in the trim tank?

1,000 kg Signup and view all the answers

Which tool is specifically mentioned for operating the drain valves?

PURGER tool Signup and view all the answers

How many drain valves are located in each wing tank?

7 Signup and view all the answers

What should you verify after draining the water from the drain valves?

Check for leakage at the drain valve Signup and view all the answers

What is the recommended procedure if the drain valve leaks?

Push up and release the drain valve again Signup and view all the answers

What is the reason for waiting one hour after refueling before draining water from the tanks?

To let the fuel stabilize Signup and view all the answers

What is one of the environmental precautions mentioned regarding waste fluids?

Sort waste fluids properly Signup and view all the answers

What is the purpose of the THS adjustment to 0° trim during drain procedures?

To facilitate gravity purging Signup and view all the answers

What action can be taken if the refuel isolation valve solenoid fails during refueling?

The valve can be manually plunger operated. Signup and view all the answers

In the event of a crossfeed valve failure, what is the protocol according to the MEL/deactivation procedures?

Use the manual override for controlling fuel flow. Signup and view all the answers

What is the main consequence of a failure in the electrical control of the refuel isolation valve solenoid?

Fuel pressure will not be able to open the valve. Signup and view all the answers

What type of valve is specifically mentioned in relation to the fuel line maintenance briefing?

Refuel isolation valve Signup and view all the answers

Which component failure requires manual intervention during the refueling process?

Refuel isolation valve Signup and view all the answers

What energizes the refuel isolation valve solenoid during the refueling process?

Fuel pressure from the tanker/pump unit Signup and view all the answers

Which of the following statements accurately describes an action taken during refueling if a valve failure occurs?

Refueling can continue if manual plunger operation is viable. Signup and view all the answers

What is the function of the solenoid in the refuel isolation valve system?

To open the valve automatically when energized. Signup and view all the answers

What is the appropriate action when there is a crossfeed valve failure during normal operations?

Refer to the MEL and dispatch the aircraft with the valve CLOSED. Signup and view all the answers

During routine checks, what is essential for daily maintenance of the fuel system?

Drain water content and implement environmental precautions. Signup and view all the answers

What is the purpose of the MEL in the context of a valve failure?

To provide guidelines for dispatching with inoperative systems. Signup and view all the answers

What is indicated by the presence of water in the fuel system?

Fuel contamination requiring immediate action. Signup and view all the answers

What procedure must be followed if the aircraft is in Extended Range operations and experiences a crossfeed valve failure?

Refer to the MEL and assess operational limits. Signup and view all the answers

What could potentially happen if regular checks for water content in the fuel are overlooked?

Risk of fuel system failure and safety hazards. Signup and view all the answers

Which of the following statements is true regarding the closed position of a crossfeed valve?

Prevents any fuel transfer between tanks. Signup and view all the answers

Why is environmental precaution important during daily fuel checks?

To prevent possible environmental pollution and hazards. Signup and view all the answers

What is the primary function of the FQI probes in the fuel tanks?

Determine the quantity of fuel based on capacitance Signup and view all the answers

Which statement about the compensators in the fuel system is correct?

They require full immersion in fuel for operation Signup and view all the answers

What is the role of the densitometers in the fuel management system?

To determine the density of the fuel Signup and view all the answers

How do FCMCs utilize the capacitance values from the FQI probes?

To determine the quantity of fuel in the tank Signup and view all the answers

What distinguishes the A330-200 configuration of the fuel system?

It includes an additional compensator in the center tank Signup and view all the answers

What is the electrical property measured by the FQI probes?

Capacitance Signup and view all the answers

In what condition do the fuel compensators provide accurate readings?

When they are fully immersed in fuel Signup and view all the answers

What does the FCMCs use the data from the densitometers for?

To determine fuel density for operational parameters Signup and view all the answers

Study Notes

Fuel Quantity Indicating (FQI) System

FQI probes are used to measure fuel quantity
The FQI system uses an indicator rod to determine wing volume during fuel quantity checks.
The most outboard MLI indicates fuel in the tank.

Fuel Level Sensors

Fuel level sensors in each wing tank are used to indicate fuel quantity.
Each FCMC has a maximum of 14 level-sensing channels that are connected to the FCMCs, with one connected to FCMC 1 and the other to FCMC 2.
The FCMC uses level-sensing data from these channels, along with other factors, for fuel quantity calculation.

Attitude

The aircraft attitude determines which fuel table is used for calculating fuel quantity.
The ADIRU determines aircraft attitude, which is derived from Air Data Inertial Reference Units (ADIRU) using the ALPHA call-up function in the ACMS.

Fuel Control and Monitoring Computers (FCMCs)

FCMCs receive fuel level sensing data from FQI probes.
FCMCs receive flight data on THS position from Flight Control Data Concentrators (FCDCs) and roll and pitch data from Air Data and Inertial Reference Units (ADIRUs).
They compute fuel quantity and temperature and transmit the information to the ECAM FUEL page and refuel panel indicator.

Fuel Quantity Calculation

FCMC uses fuel level data from fuel probes, fuel permittivity, and density to calculate fuel mass.
FQI measurements are used to monitor usable fuel in the tank.
The FCMC monitors fuel level data and activates warnings based on the data.
Fuel quantity data from opposite FCMCs is received by cross-wired discretes.

Fuel Tank Venting

Center and wing tank venting is controlled by an FCMC.
The FCMC closes the trim tank isolation valve when detecting low levels.
The FCMC closes all inlet valves, the refuel isolation valve, and triggers an ECAM warning when an overflow sensor becomes wet.
When any inner tank low level sensor is dry, the FCMC stops the jettison operation.
When the center tank low level sensor is dry, the FCMC stops the center tank transfer pumps.

Fuel Volume Measurement

Fuel volume is measured in liters and is calculated for odd numbers by interpolation between even numbers.

Fuel Weight Calculation

Fuel weight is based on volume and specific gravity.
Fuel weight is measured in kilograms (Kg).

Fuel Temperature Measurement

Each FCMC contains a number of temperature sensors that measure fuel temperature.
Temperature sensors send data to the FCMC.
The FCMC displays temperature information on the ECAM FUEL page.

MEL/Deactivation - Refuel Isolation Valve Failure

If the refuel isolation valve solenoid fails, the valve can be manually operated.

MEL/Deactivation - Crossfeed Valve Failure

If the crossfeed valve fails, in normal operations the aircraft can be dispatched with the valve inoperative (CLOSED) position.

Daily Checks - Drain Water Content

Two drains are in the center tank, seven in each wing, and three in the trim tank.
Water should be drained before refueling, or one hour after refueling.
The center tank drain valves are found in an access panel on either side of the fuselage.
The wing drain valves are accessible from the underside of the wing.
For gravity purging, the center and wing tanks need > 10% tank content, while the trim tank needs at least 1000 kg (2200lb).
The THS (Trim Hydraulic System) should also be moved to 0° trim.
Use the PURGER tool to operate the drain valves, ensuring at least one liter of fuel is drained.
If the drain valve leaks, push up and release the drain valve again.

Daily Checks - Environmental Precautions

Do not discharge oil, fuel, solvent, or lubricant into trash bins, soil, or the water network.
Use specific waste disposal containers for each product.
Store each product in a fire-resistant and sealed cupboard.

System Overview - A330-300 Overview

The aft APU pump starts if a low pressure is detected in the trim transfer line.
The APU fuel isolation valve controls fuel flow from the FWD inner tank to the trim transfer line.
The APU LP valve closes if an APU fire is detected.
The fuel/air separator, installed in the trim tank fuel transfer line, maintains sufficient fuel for APU operation if air enters the line.
The main transfer system controls fuel flow from the outer tanks to the two inner tanks for engine feeding.

Servicing

Automatic refueling can be done with normal electrical power or with battery power only.

Indicating - FQI Probes

Capacitive probes in each fuel tank measure fuel level.
The FCMCs (Fuel Content Measuring Computers) measure capacitance values to determine fuel volume.

Indicating - Compensators

Compensator probes measure fuel permittivity and are fully immersed in fuel.

Indicating - Densitometers

One densitometer is installed near the lowest point of each inner tank.
Densitometers measure fuel density.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the mechanisms and components involved in the aircraft Fuel Quantity Indicating (FQI) System. Gain insights into fuel level sensors, aircraft attitude impact on fuel calculations, and the role of Fuel Control and Monitoring Computers (FCMCs). Perfect for students learning about aviation systems and fuel management.