fuel systems Flashcards
an aviation fuel should have the following qualities:
- capable of being _______ and flow easily under all operating conditions
- enable engine _______ at all ground conditions and give satisfactory __lighting characteristics
- give _________ combustion under all conditions
- have as high a ________ value as possible
- minimum _________ effects on combustion systems or turbine blades
- minimum corrosive effects of fuel system components
- adequate ___________ for fuel system components
- reduce _____ risks to a minimum
an aviation fuel should have the following qualities:
- capable of being PUMPED and flow easily under all operating conditions
- enable engine STA RTING at all ground conditions and give satisfactory RElighting characteristics
- give EFFICIENT combustion under all conditions
- have as high a CALORIFIC value as possible
- minimum CORROSIVE effects on combustion systems or turbine blades
- minimum corrosive effects of fuel system components
- adequate LUBRICATION for fuel system components
- reduce FIRE risks to a minimum
AVGAS 100LL
now only used for _____ aircraft
colour of AVGAS 100LL is ____
the fuel grade identification marking for AVGAS 100LL is a single ____ band followed by a ___ rectangle with AVGAS 100LL written in _____
AVGAS 100LL
now only used for LIGHT aircraft
colour of AVGAS 100LL is BLUE
the fuel grade identification marking for AVGAS 100LL is a single BLUE band followed by a RED rectangle with AVGAS 100LL written in WHITE
AVTUR (JET A1 CONTAINING FS__)
the freezing point of jet A1 is around -__ celsius
the colour of jet A1 is _____/_________
the fuel grade identification markings for jet A1 is ___ _____ bands followed by a _____ rectangle, with jet A1 written in _____
AVTUR (JET A1 CONTAINING FSII)
the freezing point of jet A1 is around -47 celsius
the colour of jet A1 is CLEAR/COLOURLESS
the fuel grade identification markings for jet A1 is TWO BLACK bands followed by a BLACK rectangle, with jet A1 written in WHITE
FUEL SYSTEM BLANKS/COVERS
non-standard blanks must ___ be used
FUEL SYSTEM BLANKS/COVERS
non-standard blanks must NOT be used
FUEL SYSTEM ICING INHIBITOR
___ crystals can form in fuel tanks and pipelines at the very low temperatures encountered at ________
generally, this ice is formed from water that was ________ in the fuel when the aircraft was refuelled, but separated from the fuel as the temperature dropped
most aircraft have _______ on their main fuel tank filters to melt any ice that collects, which would otherwise reduce fuel flow
FUEL SYSTEM ICING INHIBITOR
ICE crystals can form in fuel tanks and pipelines at the very low temperatures encountered at ALTITUDE
generally, this ice is formed from water that was DISSOLVED in the fuel when the aircraft was refuelled, but separated from the fuel as the temperature dropped
most aircraft have HEATERS on their main fuel tank filters to melt any ice that collects, which would otherwise reduce fuel flow
MICROBIOLOGICAL CONTAMINATION
cladosporium resinae
the spores can exist in a _______ state in kerosene fuels in most parts of the world but they will propagate when water is present and the temperature is between __ and __ celsius
the general geographical zone where the conditions are favourable to fungal growths is between latitudes of __ degrees north to __ degrees south
MICROBIOLOGICAL CONTAMINATION
cladosporium resinae
the spores can exist in a DORMANT state in kerosene fuels in most parts of the world but they will propagate when water is present and the temperature is between 15 and 35 celsius
the general geographical zone where the conditions are favourable to fungal growths is between latitudes of 30 degrees north to 30 degrees south
FUEL QUALITY CONTROL
after a refuelling vehicle has been filled from a storage tank, it should be left to stand for at least __ minutes, then approximately one _______ of fuel should be drawn from the sump in order to check its quality. if ________ is found, further samples should be taken, until the result is satisfactory. _________ water in kerosene will give the fuel a cloudy appearance, and ____ water may often be readily visible, but in any case, a chemical water ________ method should be used.
FUEL QUALITY CONTROL
after a refuelling vehicle has been filled from a storage tank, it should be left to stand for at least 10 minutes, then approximately one GALLON of fuel should be drawn from the sump in order to check its quality. if SEDIMENT is found, further samples should be taken, until the result is satisfactory. SUSPENDED water in kerosene will give the fuel a cloudy appearance, and FREE water may often be readily visible, but in any case, a chemical water DETECTION method should be used.
MINIMUM FUE FLOW REQUIREMENTS
it is a design requirement that the aircraft fuel system must be capable of delivering a supply in ______ of engine demand under the most _______ operating conditions. these conditions being ____ power at ___ level with an almost _____ tank
MINIMUM FUE FLOW REQUIREMENTS
it is a design requirement that the aircraft fuel system must be capable of delivering a supply in EXCESS of engine demand under the most ADVERSE operating conditions. these conditions being FULL power at SEA level with an almost EMPTY tank
RIGID REMOVEABLE FUEL TANKS
the tank is usually constructed of _________ components welded together. a _____ or baffle(s) may be installed inside the tank to reduce the free movement of fuel called _____. the baffles are attached to the tank structure with ________ to allow a flow of fuel but reducing the surge action of the fuel
RIGID REMOVEABLE FUEL TANKS
the tank is usually constructed of ALUMINIUM components welded together. a BAFFLE or baffle(s) may be installed inside the tank to reduce the free movement of fuel called SURGE. the baffles are attached to the tank structure with APERTURES to allow a flow of fuel but reducing the surge action of the fuel
INTEGRAL FUEL TANKS
integral fuel tanks are formed within the aircraft _______ by sealing compartments like ____ sections during manufacture. internal ________ both divide the wing into a number of tanks and also prevent ______. external or _______ pipes connect the tanks to the fuel system.
INTEGRAL FUEL TANKS
integral fuel tanks are formed within the aircraft STRUCTURE by sealing compartments like WING sections during manufacture. internal DIAPHRAGMS both divide the wing into a number of tanks and also prevent SURGE. external or INTERNAL pipes connect the tanks to the fuel system.
FUEL PUMPS. ELECTRIC
these pumps are usually called _______ pumps when supplying fuel to the engines and ________ pumps when used to transfer fuel between tanks. however, both these functions are usually __________ and they can also have a jettison facility, where they then may also be called ________ pumps.
these are ___ positive displacement pumps
FUEL PUMPS. ELECTRIC
these pumps are usually called BOOSTER pumps when supplying fuel to the engines and TRANSFER pumps when used to transfer fuel between tanks. however, both these functions are usually COMBINED and they can also have a jettison facility, where they then may also be called JETTISON pumps.
these are NOT positive displacement pumps
FUEL PUMPS. OPERATION
a _____ seal is fitted between the pump and the _____, therefore any leakage which does occur will be drained _________. if any fuel is seen to be dripping from this drain, the booster pump should be ________
FUEL PUMPS. OPERATION
a GLAND seal is fitted between the pump and the MOTOR, therefore any leakage which does occur will be drained OVERBOARD. if any fuel is seen to be dripping from this drain, the booster pump should be REPLACED
PUMP POSITION. FULLY IMMERSED ‘WET BAY’
the centrifugal booster pump is normally attached directly to the ______ surface of the tank itself, for example, in integral fuel tanks
the pump is mounted o that it can be removed without _______ the tank, providing the pump incorporates a ‘_______ type’ chamber
this chamber can be isolated from the fuel in the tank by operating a simple _____ mechanism, then draining the small quantity of fuel left in the chamber before removing the inner pump.
the advantage of these ‘canister type’ pumps is that, if failure of the pump occurs, the down time of the aircraft is greatly ________ as the tanks do not require draining.
some fully immersed pumps fitted inside the tanks may be, by design, __________ or even triplicated in case of failure. therefore, the minimum equipment list may authorise flight with at least one ______ pump
PUMP POSITION. FULLY IMMERSED ‘WET BAY’
the centrifugal booster pump is normally attached directly to the LOWER surface of the tank itself, for example, in integral fuel tanks
the pump is mounted o that it can be removed without DRAINING the tank, providing the pump incorporates a ‘CANISTER type’ chamber
this chamber can be isolated from the fuel in the tank by operating a simple LEVER mechanism, then draining the small quantity of fuel left in the chamber before removing the inner pump.
the advantage of these ‘canister type’ pumps is that, if failure of the pump occurs, the down time of the aircraft is greatly REDUCED as the tanks do not require draining.
some fully immersed pumps fitted inside the tanks may be, by design, DUPLICATED or even triplicated in case of failure. therefore, the minimum equipment list may authorise flight with at least one FAILED pump
JET PUMPS
these pumps use a supply of fuel from the ‘_______ pump’ to induce a flow of fuel through a ________ connected to a pipeline
the pipeline is ducted to the ______ areas of the fuel tank drawing this fuel towards the booster pumps
the jet pump has no moving parts relying on the motive flow from the booster pump to move the fuel within the tank preventing __________ and supplying the booster pump
JET PUMPS
these pumps use a supply of fuel from the ‘BOOSTER pump’ to induce a flow of fuel through a VENTURI connected to a pipeline
the pipeline is ducted to the REMOTE areas of the fuel tank drawing this fuel towards the booster pumps
the jet pump has no moving parts relying on the motive flow from the booster pump to move the fuel within the tank preventing STAGNATION and supplying the booster pump
FUEL SYSTEM COMPONENTS. VENT SYSTEM
all fuel tanks must have provision for both ______ and _______ venting. the vent system must ensure that any large changes in pressure __________ do not build up between the fuel tank and the outside atmosphere
any large changes in pressure differential could cause serious structural _______ and fuel _____. the ideal condition is for a small ________ pressure acting on the fuel
conditions which require fuel venting are as follows:
- the inflow and outflow of ___ as the aircraft changes altitude
- the changes in fuel capacity as the aircraft is being _______ and defuelled
- the changes of fuel _______ as the fuel is being used by the engines
- the effects of ___________ changes which would cause expansion and contraction of the aircraft fuel contents (e.g. ground air temp +40 celsius, flight air temp -40 celsius)
- the allowance to discharge excess fuel to atmosphere should the __________ valve fail to close when the tank is filled
FUEL SYSTEM COMPONENTS. VENT SYSTEM
all fuel tanks must have provision for both INWARDS and OUTWARDS venting. the vent system must ensure that any large changes in pressure DIFFERENTIAL do not build up between the fuel tank and the outside atmosphere
any large changes in pressure differential could cause serious structural DAMAGE and fuel LEAKS. the ideal condition is for a small POSITIVE pressure acting on the fuel
conditions which require fuel venting are as follows:
- the inflow and outflow of AIR as the aircraft changes altitude
- the changes in fuel capacity as the aircraft is being REFUELLED and defuelled
- the changes of fuel CONTENTS as the fuel is being used by the engines
- the effects of TEMPERATURE changes which would cause expansion and contraction of the aircraft fuel contents (e.g. ground air temp +40 celsius, flight air temp -40 celsius)
- the allowance to discharge excess fuel to atmosphere should the REFUELLING valve fail to close when the tank is filled