FUEL SYSTEM Flashcards
What is the freezing point of a fuel?
the temperature at which solid particales begin to from in the fuel
How many microns are in one inch?
about 25,400
How are aircraft engine fuels classified?
as inflammable liquids
What is an inflammable material?
Any material that ignites easily and burns rapidly
How do aircraft fuels compare to water in liquid form?
they are lighter than water
How do aircraft fuels compare to air in vapor form?
they are heavier than air
What must happen for fuel to burn or explode?
it must vaporize and the vapor be mixed in a given percentage of air
What does the volatility of a fuel effect?
Starting, rage, and safety
What characteristic of a fuel shows the tendency to vaporize at specific temperatures?
the vapor pressure
What is measured by the distillation measurement for volatility?
the amount of fuel boiled off at specific temperatures
What is the purpose of the fuel system?
to deliver a uniform of clean fuel under constant pressure to the engine under all operating conditions
What are the 2 parts of the aircraft fuel system?
- the airframe fuel system consisting of fuel tanks, float-operated transfer valves, selector and shutoff valves, and fuel tank boost pumps
- The engine fuel system
Who controls the emergency system that is not fully automatic?
the pilot
What measures the ability of a liquid to convert to a vaporous state?
volatility
How is the volatility of a petroleum fuel measured?
in terms of vapor pressure pressure and distillation
How is vapor pressure measured?
In a Reid Vapor Pressure Test Bomb
What is the flash point?
the temperature at which the fuel vaporizes enough to ignite with an outside heat source
What flash point do ships require for storage for safety reasons?
140*F
What is a calorie?
the amount of heat needed to raise the temperature of a 1 gram of water 1 degree celsius
What is a BTU?
The amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit; 1 BTU=252 calories
What is the internal resistance of a liquid that tends to prevent it from flowing?
Viscosity
What must fuel have for satisfactory handling characteristics?
it should be noncorrosive and should not clog fuel filters, even at very low temperatures.
What is slugging?
the process by which liquid fuel is carried along with vaporized fuel when the vapor escapes to the atomsphere
How are U.S. Military grades of jet fuel designated>
JP followed by a number
What original herosene-type fuel used in turbine engines had characteristics of low vapor pressure and high energy content per volume of fuel?
JP-1
What has a fuel mixture of 65% gasoline and 35% kerosene?
JP-3
What fuel is an alternate fuel to JP-5 for USN jet aircraft used at shore stations only and is never used on ships?
JP-4 (NATO Code F-40)
What is the fuel density of JP-4?
6.5 LBS per gallon and is flash point is below 0*F
What fuel is the Navy’s primary jet fuel?
JP-5
Which fuel is similar to JP-5 in most characteristics, except flash point and freeze point and is now available only in Europe?
JP-8 (NATO Code F-34)
What are the common commercial fuels used?
types A, A-1, and B
When are commercial fuels authorized for use in military aircraft?
When JP fuel is not available
How is commercial fuel characterized with military fuel?
A-1 is designated NATO code F-34, or equal to JP-8; Jet A is equal to JP-5 and Jet B is equal to JP-4
How do you determine how much contamination is too much?
by understanding the units of measurements used to identify contamination, which are mircons for solids and parts per million (ppm) for water
Since parts per million is the reference for water contamination, what happens if you take a 32oz. sample bottle and fill it 3 1/4 inches from the bottom?
you have about 500 cubic centimeters (cc); break the 500 down into one million little pieces and you now have 1 ppm
what is the color of jet fuel?
it varies from clear, water white to straw-yellow in color
What does a clean color of jet fuel mean?
the absence of any cloud, emulsion, visible sediment, or free water.
What does a bright color of jet fuel mean?
The fuel has a shiny, sparkling appearance
How is free water defined?
a cloud, emulsion, droplets, or gross amounts in the bottom of the container.
How is free water defined?
A cloud, emulsion, droplets, or gross amounts in the bottom of the container
What is the size of course sediment?
10 microns and fine sediments are less than 10 microns and are not visible as distinct or separate particles
What is the major constituent causing many of the problems associated with biological contamination of jet fuels?
fungus
What is fungus?
a vegetable life that holds rust and water and is a stabilizing agent for fuel-water emulsion
What is the color of microbiological growth?
Brown, black, or gray color and has a stringy, fibrous-like appearance.
What are the most commonly used types of self-sealing fuel cells?
the standard construction type and the type that uses a bladder along with the self-sealing cell.
When should samples of fuel be sent to the nearest Navy Petroleum Laboratory for microbiological growth determination?
if dark stringy or fibrous material tends that uses a bladder along with the self sealing cell
What is a self-sealing cell fuel container?
one that automatically seals small holes or damage caused during combat operations and is not bullet proof, merely, puncture sealing
Which fuel cell is used the most and is a semiflexible cell, made up of numerous plies of material?
the standard construction cell
What are the 2 parts of the combination bladder and self sealing cell?
One is a bladder-type cell and the other is identical to the standard construction cell.
What is the inner liner material used inside the self-sealing fuel cell made of?
Buna N synthetic rubber
What is the purpose of the inner liner material found inside of the self sealing fuel cell?
to contain the fuel and prevent if from coming in contact with the sealant
what is Buna rubber, an artificial substitute for crude or natural rubber, produced from?
Butadine and sodium
What is the purpose of the nylon fuel barrier?
to prevent the fuel from diffusing farther into the cell
What is the function of the sealant material?
it remains dormant in the fuel cell until the cell is ruptured of penetrated by a projectile then the sealant seals the ruptured area>
What is the purpose of the retainer?
to provide strength and support and also increases the efficiency of the mechanical action by returning the fuel cell to its original shape when punctured
What fuel cell is commonly called a bladder-type cell?
a nonself-sealing type
what are the 2 types of bladder-type fuel cells?
rubber type and nylon type
what is the purpose of the inner liner of the rubber-type bladder fuel cells?
to contain the fuel and provide protection for the nylon barrier