Fuel Systems Flashcards
List some of the safety precautions used to reduce fire hazards when performing maintenance on fuel systems
Aircraft electrical power secured and tagged. Position fire extinguisher near work area. Do not smoke within 50ft. Do not use open flame in or around aircraft. Only use explosion-proof lighting equipment. Do not refuel or defuel aircraft inside hangar. Proper grounding. Proper ventilation. All tools must be non-sparking.
What are the three types of numbers used to designate grades of jet fuel?
U.S. Military- JP followed by a number, Commercial, NATO (North Atlantic Treaty Organization)- codes are given to grades of fuel for worldwide use.
List the most common types of fuels used by U.S. Military and their weight conversions: **
JP-4: Jet B, F-40, 6.35 lbs/ JP-5: Jet A, F-44, 6.80 lbs/ JP-8 : Jet A-1, F-34, 6.70 lbs
After fueling, what conversion do you use to calculate and monitor the weight and balance of the aircraft?
Multiply the number of gallons by the weight per gallon. Example: 200 gal of jp-5 x 6.80= 1360lbs
What two types of fuel cells may be used in present day aircraft?
Integral tanks and Bladder-type cells
Where are integral tanks normally built into and what is this referred to as?
Built into the wings or structure, referred to as a “wet wing.”
What are bladder-type cells made of and why are they used?
Synthetic rubber or nylon fabric. Used to reduce weight on aircraft.
What three types of fuel pumps are used in aircraft fuel systems?
Transfer, boost, and dump
What is the function of a fuel pump?
Supplies fuel under pressure to the engine, transfer fuel from tank to tank or to dump fuel overboard if necessary.
What is the function of fuel ejectors?
Assist in the transfer of fuel from one tank to another tank, increase volume of fuel flow, and keep the surge box full.
What is the purpose of the float valve assembly?
Used to regulate fuel entering a tank.
What are fuel lines made of normally and what are they made of when subject to abrasion or intense heat?
Aluminum alloy, stainless steel
How are fuel lines identified?
Color-coded identification tape wrapped around the tubing. tape is red in color and has a symbol of a four-sided star.
What are the three types of actuation of fuel control valves? Give a brief example.
Manual- switch in cockpit or cabin. Electric- motor or solenoid operated. Pressure- spring or diaphragm senses pressure and opens at pre-set pressure.
What are fuel strainers and where are they installed?
Strainers made of coarse mesh that prevent large particles from entering the fuel system. Installed in tank outlets and frequently in tank filler necks.
What requires all aircraft to have a fuel gauge that indicates the quantity of fuel in each tank and what are the three types of indicating systems?
FAR: Federal Aviation Regulations. Capacitance-type indicating system, Magnetic sight gauge indicating systems, and Fuel quantity low-level warning system.
How does a capacitance-type fuel quantity indicating system differs from the other types?
It has no movable devices in the fuel tank.
Give a brief description of a capacitance-type indicating system and it’s components.
Electronically measures fuel weight (not gallons) of the fuel in the tanks. Indicator, compensator, tank probes, and amplifier.
What three types of fuel quantity indicators are typically used on CG aircraft?
Digital, Radial, and Vertical scale
What two types of tank probes are there and how do they work?
Non-Characterized (symmetrical tanks) and Characterized (oddly shaped tanks). Sense fuel weight by the change in capacitance and sends a signal to the amplifier.
Magnetic sight gauges provide a manual way to check fuel quantity and consist of what?
Consists of a plastic indicator rod (dipstick) and a float. Dipstick is encased and uses glycol for buoyancy.
What components make up a fuel quantity low-level warning system?
Low-level switches or probe mounted in tank, warning lights in the cockpit, and associated wiring
