Fuel / Hydraulics / Ice and Rain Flashcards
What subsystems does the fuel system usually consist of?
Storage and Fuel Ventilation Fuel feed Refueling / Defueling FQIS Fuel Jettison Longitudinal Trim
Where are fuel tanks located?
Wings, Fuselage and Horizontal Stabilizer
Where in a tank would you find fuel sumps and drains?
At the lowest point
What are tanks fitted with to prevent fuel surges due to altitude change and turns?
Baffles
What is the most commonly used type of fuel tank on large transport aircraft?
Integral
What are the most common methods of sealing fuel tank panels?
O-Rings and Gaskets
Why are fuel tanks ventilated?
To prevent structural damage
How large must the expansion space of a fuel tank be?
Not less than 2% of the tank capacity
Why is tank draining carried out?
To remove sediment and fuel residue from the tank. Also to remove water from the tanks to prevent freezing.
Why is it sometimes necessary to use vacuum apparatus in tank draining?
When the drain valve is not located at the tanks lowest point.
Why are drain valves fitted with a check valve?
It means the assembly can be replaced if leaking without the need of draining the fuel tanks.
What is a rule to properly drain any existing water from a fuel tank?
The tanks must be left to settle for a certain period of time
What sis the main advantage of a ‘fuel pump canister’
It can be removed without the need to drain the tanks
Which component isolates the engines in the case of engine failure?
Low pressure shut off valves
In what tanks would you find jet pumps?
In vent surge tanks or Centre tanks where no direct fuel feed to the engine takes place.
What is the purpose of an Air Release Valve?
It releases air trapped in the fuel feed line. Installed at the highest point of the fuel line
It is a requirement that fuel can be transferred between tanks. In which cases does this become necessary?
If the fuel supply of a main tank to its engine stagnates
What is a meant by the term ‘Probe’?
A measuring device that consists of 2 concentrically mounted tubes in open connection to the tank. These tubes form the plates of a capacitor.
What is the variable in the tank that affects the dielectric constant?
The ratio of fuel to air
In what case would you use the dipstick method to measure fuel level?
When there is no electrical power available
The fuel dump system is also called the?
Fuel Jettison System
What is fuel dump used for in aviation?
To bring the aircraft to a safe landing weight or go around weight.
What are some warning provided by the fuel system?
Tank Level (High and Low), System Components Inop, Fuel Imbalance, Impossible Fuel Transfer.
What is the most common type of hydraulic fluid?
Skydrol
What are the most important systems that Hydraulics supplies?
Flight Controls and Landing Gear
Why are Hydraulic tanks pressurized?
To prevent frothing and ensure there is a supply always available.
What are the two types of hydraulic accumulators?
Spherical and Piston
Main hydraulic pumps are usually of the ………………………. type?
Variable Piston Pump
What is the purpose of a hydraulic fluid reservoir?
- Have a supply of fluid available
- Absorb differences in level when in use
- Let fluid cool off, settle and release vapor bubbles
In depressurized mode the wobble plate is in the ……………. position?
Angled
What is another name for a maintaining valve?
A priority valve
3000psi is equivalent to …….. Bar?
210
What is the first component in the pressure line from the EDP?
A switch to warn if pressure is too low
Never operate a hydraulic system with pressure released in the …………. ?
reservoir
What type of pumps are hydraulic electrical pumps?
Gear type or Variable Piston
What two parts does a PTU consist of?
Motor and a Pump
How much fluid is transferred when the PTU is in operation?
None
When is a PTU is automatic mode?
In flight and on the ground
At what percentage roughly are hydraulic pressure relief valves operated?
10-20%
What are the two types of hydraulic fluids?
Mineral and Synthetic
What fluid is skydrol?
Phosphate ester
How is the fluid filter element monitored?
A differential indicator
what Colour is the band on a hydraulic seal?
Green
At what pressure will a check valve operate?
15-20 PSI
What hydraulic parameters are usually indicated in the cockpit?
Temp, Pressure, Output pressure and Quantity
What are the effect of ice on the forces of an aircraft?
Drag and Weight increases while Lift and Thrust reduces
Frost is removed from an aircraft by spraying it with a mixture of?
Ethylene Glycol + Isopropanol Alcohol
What is the purpose of an ice detection spotlight?
To illuminate parts of the aircraft that are prone to icing so the crew can visually monitor it
When is it allowed to apply chemical rain repellent to the windshield?
Only when then windshield is wet otherwise it will smear
Ice will only form on an aircraft when?
flying through cloud or precipitation where the water droplets are super cooled
What type of ice freezes immediately on impact and has a rough and generally opaque formation?
Rime Ice
what type of ice takes a while to freeze so contains air bubbles and has time to run back?
Gleam Ice
What type of ice forms in the air in small crystals and can cause blocking of intakes in sufficient volume?
Dry Ice
What type of ice is cooled slowly and so runs back in a clear smooth fashion?
Clear or Glaze Ice
Where is the ‘Wheel Base’ measured from?
From the centre of the boogie beam from NLG to MLG
Where is the ‘Wheel Track’ measured from?
From the centre of the boogie beam from left to right main landing gear
During landing kinetic energy is transferred into?
Heat energy
When 4-6 wheels are connected to a landing gear they are connected to?
Boogie beams and gear trucks
What is the function of the fluid inside the strut?
Slows down the strut movement during the extension od the shock absorber
In what part of the gear would you find fluid and nitrogen?
In the strut combined within the shock absorber
What other sub-systems are in the landing gear system?
- The brake system- The NWS system- The flight/ground switching system
Is it possible to move the landing gear handle on the ground?
yes
How does the emergency landing gear extension system work?
From a handle in the flight deck the gear can be manually unlocked via control cables. Gravity allows the gear to fall and bungee springs hold it in the locked position.