Aircraft Fuel Systems Flashcards
Fuel jettisoning is usually accomplished
through a common manifold and outlet in each wing
The primary purpose of aircraft fuel jettison system is to quickly achieve a
lower landing weight
Fuel jettison valve must be designed to allow flight personnel
to close the valve at any time and the fuel must discharge clear of the aircraft
Which of the following is employed to maintain lateral stability when jettisoning fuel?
Two separate independent systems
A fuel jettison system is required under certain conditions if the maximum takeoff weight exceeds the maximum landing weight. What regulation covers the requirements of fuel jettison?
(FAR) 14 CFR 23, 25 and CAM 4b
Fuel is moved overboard in most fuel jettison systems by
boost pumps
Fuel jettisoning past the limits prescribed by Federal Aviation Regulations is usually prevented by
dump limit valves or a low-level circuit
Which procedure must be followed when defuelling aircraft with sweptback wings?
Defuel outboard wing tanks first
Normal fuel crossfeed system operation in multi-engine aircraft
provides a means to maintain a balanced fuel load condition
How many vents, arranged so that they are not likely to become plugged at the same time, must be used in multi engine fuel systems?
Two
What is the primary purpose of the cross-feed system?
It allows any tank to supply fuel to any engine
Fuel system components must be bonded and grounded in order to
drain off static charges
How many engine driven fuel pumps per engine are required for engines requiring fuel pumps?
One fuel pump for each engine
A typical lathe transport aircraft fuel manifold system allows how many of the following?
1. All tanks can be serviced through a single connection
2. Any engine can be fed from any tank
3. All engines can be fed from all tanks simultaneously
4. A damaged tank can be isolated from the rest of the fuel system
1,2,3 and 4
A fuel system must be designed to prevent fuel vapor ignition caused by
lightning
What is the minimum distance allowed between a fuel tank and the fire wall separating the engine?
One-half inch
Fuel baffles are installed in tanks to prevent _____ caused by changes in attitude of the aircraft
Surging
Many fuel tanks incorporate ______ valves to prevent fuel from flowing away from the boost pump or tank outlet when the aircraft is in a high “G” maneuver.
flapper
Fuel heaters are used with systems for turbine engines to prevent ______ in the fuel from clogging system filters
ice crystals
A transducer in a fuel pressure system serves what function?
Converts fluid pressure directly through a transmitter to the indicator
The use of turbine fuels has resulted in some problems not normally associated with aviation gasoline. One of the problems is
Microbial contaminants
What is used in many aircraft to prevent bubbles in the fuel after it leaves the tank when atmospheric pressure is lower than fuel vapours pressure
Boost pumps
Which of the following precautions is most important during refuelling operations?
Fuel to be used must be appropriately identified
Before fuelling an aircraft by using the pressure fuelling method, what important precaution should be observed?
The truck pump pressure must be correct for that refuelling system
What flight safety-related advantage does a pressure fuelling system provide?
Reduces the chances for fuel contamination
Aircraft pressure fueling system instructional procedures are normally placarded on the
fuel control panel access door
Pressure fueling of aircraft is usually accomplished through
at least a single point connection
Which of the following may be used for the repair of fuel leaks on most integral fuel tanks?
Riveting and resealing
How is the outlet fuel pressure regulated on a submerged, single-speed, centrifugal-type fuel pump?
By the pumps design and internal clearance
What is one purpose of a fuel tank vent?
To maintain atmospheric pressure
When inspecting a removable rigid fuel tank for leaks, what procedure should be followed?
Pressurize the tank with air and brush with soapy water
If it necessary to enter an aircraft fuel tank, which procedure should be avoided?
Conduct the defueling and tank purging operation in an air-conditioned room
What is recommended practice for cleaning a fuel tank before welding?
Steam clean the tank interior
An aircraft integral fuel tank is
a part of the aircraft structure
Which gas is used for purging an aircraft fuel tank?
Carbon dioxide
Why is the main fuel strainer located at the lowest point in the fuel system?
It traps any small amount of water that may be present in the fuel system
The purpose of a diaphragm in a van type fuel pump is to
compensate fuel pressures to altitude changes
When moving the mixture control on a normally operating engine into the idle cutoff position, engine RPM should
slightly increase before the engine starts to die
Entrained water in aviation in aviation turbine fuel is a hazard because of its susceptibility to freezing as it passes through the filters. What are common methods of preventing this hazard?
Anti-icing fuel additives
As a general rule, which statement is true regarding fuel leaks?
Stains, seeps and heavy seeps, (in addition to running leaks) are considered flight hazards when located in unvented areas of the aircraft
The presence of fuel stains around a fuel nozzle would indicate
clogged fuel nozzle
What should be used to inert an integral fuel tank before attempting repairs
CO2
What should be used to remove flux in aluminum tank after welded repairs?
5 percent solution of nitric or sulfuric acid
What method would be used to check for internal leakage of a fuel valve without moving the valve from the aircraft?
Place the valve in the OFF position, drain the strainer bowl, and with booster pump on, watch to see if duel flows to the strainer bowl
Why are jet fuels more susceptible to water contamination that aviation gasoline?
Jet fuel has a higher viscosity than gasoline