Storage Systems - Fuel Systems - Airframes & Aircraft Systems #65

Summary

This lesson explores the different fuel storage methods in aircraft, including integral, rigid, and flexible tanks. Integral tanks are part of the aircraft's structure, offering minimal added weight and are common in large passenger planes. Rigid tanks are separate metal containers found in smaller aircraft and can be externally mounted. Flexible tanks, or fuel bladders, are used in high-performance light aircraft and military planes for their self-sealing properties. All tanks incorporate baffles to reduce fuel movement during maneuvers, and some feature baffle check valves to control fuel flow. Additional components like vents, gauging systems, and filler caps are also discussed.

Takeaways

• 🛩️ Aircraft fuel is stored in tanks that can be integral, rigid, or flexible.
• 💧 Integral tanks are formed by sealing parts of the aircraft structure like wings and stabilizers during manufacturing.
• 🔩 Rigid tanks are separate, removable containers that do not contribute to the aircraft's structural integrity.
• 🔖 Flexible tanks, or fuel bladders, are reinforced rubberized bags that are secured within the aircraft structure.
• ✈️ Modern large passenger aircraft typically use integral tanks due to their structural efficiency.
• 🏞️ Smaller general aviation aircraft often use rigid tanks, which may be mounted externally on the wingtips.
• 🔒 Flexible tanks are popular in high-performance light aircraft and military aircraft for their self-sealing capabilities.
• 🚫 Integral tanks minimize extra weight as they utilize existing aircraft structure.
• 🔄 Baffles are installed in fuel tanks to restrict fuel movement and reduce inertial forces during maneuvers.
• 💧 Baffle check valves may be used to allow fuel flow inboard but restrict outboard flow towards wingtips.

Q & A

What are the different methods for storing fuel onboard an airplane?

There are three main methods for storing fuel onboard an airplane: integral tanks, rigid tanks, and flexible tanks.

How are integral tanks created and what is their advantage?

Integral tanks are created by sealing the insides of the wings, horizontal stabilizers, and the center section torsion box during manufacture. Their advantage is that they add little extra weight to the aircraft as they are formed from the structure already required.

In which types of aircraft are integral tanks commonly found?

Integral tanks are commonly found in all modern large passenger aircraft.

What are rigid tanks and where are they typically installed?

Rigid tanks are sealed containers mounted in or on the aircraft wing or fuselage. They are typically installed in a compartment designed to accommodate the tank and are commonly found in smaller general aviation aircraft.

What material are rigid tanks usually made of?

Rigid tanks are usually made of metal and may be removed for inspection, replacement, or repair.

What is a flexible tank and what are they sometimes called?

A flexible tank is a reinforced rubberized bag installed in a section of the aircraft structure. They are sometimes referred to as fuel bladders or bag tanks.

Why are flexible tanks often used in high-performance light aircraft and military aircraft?

Flexible tanks are often used in high-performance light aircraft and military aircraft because they are less likely to split on impact and can be effectively self-sealing in the event of minor battle damage.

What is the purpose of baffles fitted inside larger aircraft fuel tanks?

Baffles are fitted inside fuel tanks to restrict the movement of the fuel and minimize the large inertial forces generated when the fuel surges during aircraft maneuvers.

What are baffle check valves and how do they function?

Baffle check valves allow fuel to flow inboard but restrict its flow outboard towards the wingtips during maneuvers, helping to control fuel movement within the tank.

What additional components are found in aircraft fuel tanks, especially in larger aircraft?

In larger aircraft, fuel tanks also incorporate vents, a gauging system, water drains, filler caps, booster pumps, low-level float switches, and pressure refueling valves.

Why are vents and water drains important in aircraft fuel tanks?

Vents are important for allowing air to escape as fuel is added, preventing overpressurization, while water drains are used to remove any water that may accumulate at the bottom of the tank, which can contaminate the fuel.

Outlines

00:00

🛩️ Aircraft Fuel Storage Methods

This paragraph discusses the different methods for storing fuel on an aircraft. It explains the use of integral, rigid, and flexible tanks. Integral tanks are formed by sealing parts of the aircraft structure like wings and stabilizers, offering large storage volumes with minimal added weight. Rigid tanks are separate, removable containers typically found in smaller aircraft, not contributing to the aircraft's structural integrity. Flexible tanks, or 'bladders,' are used in high-performance light aircraft and military planes for their self-sealing properties. All tanks include baffles to reduce fuel movement during maneuvers, and some may have baffle check valves to control fuel flow. The paragraph also mentions additional tank components like vents, gauging systems, and filler caps, with larger aircraft having more complex systems.

Keywords

💡Integral Tanks

Integral tanks are a type of fuel storage system in aircraft where the fuel tanks are created by sealing the insides of the wings, horizontal stabilizers, and sometimes the center section of the aircraft during manufacturing. These tanks are an integral part of the aircraft's structure, meaning they contribute to the overall strength and rigidity of the aircraft. The advantage of integral tanks, as mentioned in the script, is that they add minimal extra weight since they utilize the existing structure. This type is commonly used in modern large passenger aircraft.

💡Rigid Tanks

Rigid tanks are sealed containers that are mounted within or on the aircraft's wings or fuselage. Unlike integral tanks, these do not contribute to the aircraft's structural integrity and can be removed for inspection, replacement, or repair. They are typically made of metal and are found in smaller general aviation aircraft. The script mentions that rigid tanks may also be externally fitted, such as on wingtips, and can be made of metal or composite materials.

💡Flexible Tanks

Flexible tanks, also known as fuel bladders or bag tanks, are reinforced rubberized bags that are installed within a compartment of the aircraft designed to handle their weight. These tanks are secured by metal buttons or snaps and are used in high-performance light aircraft and some smaller turboprops. As highlighted in the script, flexible tanks are preferred in military aircraft because they are less likely to split on impact and can self-seal in case of minor battle damage.

💡Baffles

Baffles are internal structures fitted within fuel tanks to restrict the movement of fuel and minimize the inertial forces generated during aircraft maneuvers. They play a crucial role in preventing fuel from sloshing around, which could affect the aircraft's balance and control. The script explains that all larger aircraft fuel tanks have baffles, which are essential for safe and stable flight operations.

💡Fuel Surge

Fuel surge refers to the movement of fuel within the tanks during aircraft maneuvers, which can create large inertial forces that affect the aircraft's balance. The script emphasizes the importance of baffles in minimizing fuel surges, ensuring that the aircraft remains stable and manageable during various flight conditions.

💡Baffle Check Valves

Baffle check valves are a specific type of valve that allows fuel to flow in one direction (inboard) but restricts its flow in the opposite direction (outboard towards the wingtips) during maneuvers. As mentioned in the script, these valves help control fuel movement within the tanks, further enhancing the aircraft's stability during flight.

💡Vents

Vents are openings in the fuel tanks that allow air to escape or be drawn in as the fuel level changes. They are crucial for maintaining a balanced pressure within the tank and preventing over-pressurization or vacuum conditions. The script includes vents as part of the fuel tank system, indicating their importance in aircraft fuel management.

💡Gauging System

A gauging system is a set of instruments and sensors used to measure the quantity of fuel in the tanks. This system is vital for monitoring fuel levels and ensuring that the aircraft has enough fuel for the intended flight. The script implies that larger aircraft have more complex gauging systems to manage their fuel more accurately.

💡Water Drains

Water drains are components of the fuel tank system designed to remove any water that may have accumulated at the bottom of the tank. Water can contaminate the fuel and cause damage to the engine, so these drains are essential for maintaining fuel quality. The script lists water drains as part of the fuel tank's features, indicating their role in aircraft maintenance.

💡Filler Caps

Filler caps are the covers for the openings through which fuel is added to the tanks. They are important for sealing the tank and preventing the escape of fuel vapors or the entry of contaminants. The script mentions filler caps as part of the fuel tank's components, highlighting their role in safe fuel handling.

💡Booster Pumps

Booster pumps are used in larger aircraft to assist in moving fuel from the tanks to the engines. They ensure that fuel is delivered at the necessary pressure and flow rate, especially in aircraft with long distances between the tanks and engines. The script includes booster pumps as part of the fuel tank system in larger aircraft, indicating their importance in fuel management.

Highlights

Various methods used for storing fuel onboard an aeroplane

Fuel is carried in tanks within the aircraft, which can be integral, rigid, or flexible

Integral tanks are formed by sealing parts of the aircraft structure during manufacture

Integral tanks offer the advantage of adding little extra weight to the aircraft

All modern large passenger aircraft utilize integral type tanks

Rigid tanks are sealed containers mounted in or on the aircraft wing or fuselage

Rigid tanks are commonly found in smaller general aviation aircraft

Flexible tanks, or fuel bladders, are reinforced rubberized bags

Bladder tanks are used in high-performance light aircraft and some smaller turboprops

Flexible tanks are less likely to split on impact and can self-seal in case of minor battle damage

Baffles are fitted inside larger aircraft fuel tanks to restrict fuel movement

Baffles minimize the inertial forces generated during aircraft maneuvers

Some aircraft have baffle check valves to control fuel flow during maneuvers

Fuel tanks incorporate vents, a gauging system, water drains, and filler caps

Larger aircraft tanks feature booster pumps, low-level float switches, and pressure refueling valves

The lesson emphasizes the types of fuel tanks and their functions in aircraft

Transcripts

in this short lesson we will examine the

various methods used for storing fuel

onboard an aeroplane

the view is carried in or on the

aircraft within tanks

which can be integral rigid or flexible

integral tanks are made by sealing

during manufacture the insides of the

wings

and depending on type the horizontal

stabiliser

and the center section torsion box

between the wings to provide large

volume for storage

the advantage of the integral type tank

is that there is little extra weight

added to the aircraft as the tank is

formed from the structure already

required

all modern large passenger aircraft will

have this type of tank

a rigid tank is a sealed container

mounted in or on the aircraft wing or

fuselage

rigea tanks are installed in a

compartment designed to accommodate the

tank they are typically of metal

construction and may be removed for

inspection replacement or repair

the aircraft does not rely on the tank

for structural integrity

these tanks are commonly found in

smaller general aviation aircraft

rigid tanks may be fitted externally on

the wingtip for example

they may be made of metal or other

composite construction

flexible tanks are reinforced rubberized

bags installed in a section of the

aircraft structure designed to

accommodate the weight of the fuel

they are sometimes referred to as fuel

bladders or bag tanks

the bladder is secured by means of metal

buttons or snaps inside the compartment

many high-performance light aircraft and

some smaller turbo props use bladder

tanks

they are also often fitted in military

aircraft as they are less likely than

the other two types to split on impact

and they can be effectively self-sealing

in the event of minor battle damage

occurring

all the larger aircraft fuel tanks have

baffles fitted inside them

baffles are fitted within the tank to

restrict the movement of the fuel and

minimize the large inertial forces

generated when the fuel surges during

aircraft maneuvers

some aircraft may be fitted with baffle

check valves which allow the fuel to

flow in board but restricts its flow

outboard towards the wingtips during

maneuvers

fuel tanks also incorporate vents

a gauging system

water drains and filler caps

in larger aircraft the tanks will also

have booster pumps

low level float switches

and pressure refueling valves these

components will all be explained in

detail in later lessons

the main points to be taken from this

lesson are that aircraft fuel tanks can

be integral rigid or flexible

and the baffles are fitted in the tanks

to minimize fuel surges during aircraft

maneuvers

remember that some aircraft may be

fitted with baffle check valves which

allow the fuel to flow in board but

restrict its flow outboard towards the

wingtips during maneuvers