Aircraft Fuel System Flashcards
Fuel jettisoning is usually accomplished
through a common manifold and outlet in each wing
The primary purpose of an aircraft’s fuel jettison system is to quickly achieve a
lower landing weight
(1) The fuel jettison valve must be designed to allow flight personnel to close the valve during any part
of the jettisoning operation.
(2) During the fuel jettisoning operation, the fuel must discharge clear of any part of the airplane.
Regarding the above statements,
both no. 1 and no. 2 are true
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 regulations cover the requirements of fuel jettisoning?
Federal Aviation Regulation Part 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 defueling aircraft with sweptback wings?
Defuel the outboard wing tanks first
(Refer to Figure 17.) What is the purpose of the pump crossfeed valve?
ans. allow operation of engines from one tank
Normal fuel crossfeed system operation in multiengine aircraf
provides a means to maintain a balanced fuel load condition
What is the primary purpose of the crossfeed system?
to allow the feeding of any engine from any tank
Fuel system components must be bonded and grounded in order to
drain off static charges
A typical large 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
The use of turbine fuels in aircraft has resulted in some problems not normally associated with aviation
gasolines. One of these 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 vapor pressure?
boost pumps
Which of the following precautions is most important during refueling operations?
fuel to be used must be appropriately identified
Before fueling an aircraft by using the pressure fueling method, what important precaution should be
observed?
the truck pump pressure must be correct for that refueling system
What flight safety-related advantage does a pressure fueling system provide?
reduces the chances for fuel contamination
Aircraft pressure fueling systems instructional procedures are normally placarded on the
fuel control panel access door
Pressure fueling of aircraft is usually accomplished through
at least one single 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 pump’s design and internal clearances
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?
pressure the tank with air and brush with soapy water
If it is necessary to enter an aircraft’s fuel tank, which procedure should be avoided?
conduct the defueling and tank purging operation in an air conditioned building
What is the recommended practice for cleaning a fuel tank before welding?
steam clean the tank interior
An aircraft’s 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 small amount of water that may be present in the fuel systems
The purpose of a diaphragm in a vane-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 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 and fuel heater
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 inert an integral fuel tank before attempting repairs?
5 percent solution of nitric or sulfuric acid
What method would be used to check for internal leakage of a fuel valve without removing the valve
from the aircraft?
place the valve in the off position, drain the strainer bowl, and with boost pump on, watch to see if
fuel flows to the strainer bowl
Why are jet fuels more susceptible to water contamination than aviation gasoline?
jet fuel has a higher viscosity than gasoline
When installing a rigid fuel line, 1/2 inch in diameter, at what intervals should the line be supported?
16 inches
The probe of a capacitance-type fuel level gauge is essentially a
capacitor with fuel and air acting as a dielectric
Which statement concerning an electronic capacitance-type fuel quantity indicating system is true?
it has no moving parts in the tank
What type of remote-reading fuel quantity indicating system has several probes installed in each fuel
tank?
electronic
Which aircraft fuel quantity indicating system incorporates a signal amplifier?
electronic
A drip gauge may be used to measure
the amount of fuel in the tank
The electronic-type fuel quantity indicating system consists of a bridge circuit,
an amplifier, an indicator, and a tank unit
A probe or a series of probes is used in what kind of fuel quantity indicating system?
capacitor