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Questions tagged [fuel-systems]

Any question regarding aircraft fuel systems, how they work etc.

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1answer
53 views

What is the difference between staged and unstaged fuel manifolds? [closed]

Also, I would like to know the difference between pilot, primary and secondary fuel flow.
3
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1answer
115 views

Is fuel in trim tank usable?

Some aircraft (A380, Concorde,...) are equipped with a trim tank in the tail. Transferring fuel from or to this tank help controlling the CG. This feature can only be achieved if there is fuel to ...
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1answer
67 views

What is the difference between fuel control unit and fuel flow meter (transmitter)?

Hello can someone explain the difference between the fcu and fuel flow transmitter and how they work together alongside the fuel pump?
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2answers
1k views

Was there ever a fuel-injected Spitfire?

I couldn't find one but did it ever exist? Would adding fuel injection have improved combat effectiveness or fuel efficiency?
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4answers
15k views

Why didn’t the Captain of Cathay Pacific flight 780 shut down engine 1 and land with a more reasonable speed?

In the approach phase, engine 1 of Cathay Pacific flight 780 got stuck at about 70% N1 and it forced the crew to do an overspeed landing (230knots). Why didn't they shut it off by turning the fuel ...
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3answers
357 views

What causes fuel gauges to be untrustworthy?

I went on my first flight yesterday (Cessna 152), and I was told not to trust the fuel gauges and to check fuel levels manually. The instructor said that the only fuel gauge reading that I can trust ...
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4answers
4k views

What is the purpose of the fuel shutoff valve?

Most GA planes have a fuel shutoff valve which I don't quite understand the purpose of. Does it cut the fuel flow with the mixture. My theory is to prevent fuel flow at earlier stage for safety ...
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0answers
79 views

Are there design guidelines for sizing vent/surge tanks?

Could someone explain the sizing process of Vent/ Surge tank of Aircraft fuel system? I understand the Vent tank is to collect fuel overflow from the main fuel tanks. The reason could be due to Fuel ...
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0answers
56 views

Airbus a380 fuel system [duplicate]

Does the aibus a380 has center tank compare with a320,in this picture above,it shows that it has 11 tanks including the wings and the elevator while many aircraftshas together with the center tank (i ...
6
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1answer
609 views

Does the mixture and throttle setting affect the quality of priming of fuel prior to start?

This question is a generality. For airplanes with small reciprocating engines, does the mixture and throttle setting at the time of priming affect the quality of the priming or the engine start, or ...
1
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1answer
210 views

How do you lean mixture using only the instruments on a C172 Skyhawk?

POH manuals always tells to use the voice of the engine as a reference. (Which complicates things a little bit since carbs and fuel injected planes have different "reaction times" for each cylinder) ...
8
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1answer
242 views

Why was the Graf Zeppelin's endurance when fully fuelled with both fuels less than the sum of its endurances with each fuel separately?

The LZ-127 Graf Zeppelin used a unique dual-fuel system, with both a gasoline tank and a set of gas cells filled with blau gas; the airship could be flown using either fuel or both. The purpose of ...
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2answers
403 views

Why is the fuel pump in the startup procedure for a Cessna 172?

I thought fuel pumps were reserved for fuel injected planes in startups and during critical flight phases for all planes? However. There are some X-Plane flight tutorials that tells us to use fuel ...
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1answer
88 views

Why doesn't the Convair 580 have check valves to prevent inadvertent fuel transfer?

The Convair 580's fuel system is composed of two wing-mounted fuel tanks (one in each wing), each with its own shutoff valve (which can be closed to isolate its respective tank from the rest of the ...
6
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4answers
590 views

Why is alcoholic gasoline such a showstopper for aviation?

One of the main reasons the common avgas grades are still full of 3-plumba-3,3-diethylpentane is the incompatibility of many aircraft fuel systems with the oxygenates (primarily ethanol, with some ...
9
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1answer
507 views

Why would the outer tanks fuel on the A320 be colder than the inner tanks?

I have noticed in a number of instances during long flights typically over 5 hours the fuel in the outer tanks on the A320 are colder than the fuel in the inner tanks. This goes against the system ...
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2answers
266 views

Why are fuel pump switches separate?

Since engines are run only when the fuel pumps are on and vice versa , why are there separate switches for this? Why can't it be automated ?
4
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1answer
308 views

In normal condition, is the Airbus A320 APU fuel supplied by the main engine boost pump only?

I have a question relating to APU fuel system. As said in material, there are 2 system supplying fuel for APU to operate. 1st one is primary and 2nd one is secondary. In the 1st system or low ...
4
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1answer
850 views

Where is the APU fuel pump on the A320?

I'm looking for APU fuel pump location for A320 aircraft series. I'll be much appreciated if you provide a link to some images, schemes.
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2answers
2k views

Why fuel left/right when C172 is secured?

The C172 POH checklists say to set the fuel selector to "right" or "left" when securing the plane but "both" while operating the plane. What is the point of changing the fuel selector when the engine ...
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1answer
511 views

Hydromechanical/Electronic fuel control system [closed]

Can someone explain the picture below which represents hydromechanical/electronic fuel control? What's the function of the solenoid on the picture below? What are the differences between solely ...
53
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8answers
26k views

Why are fuel tanks located in wings?

Passenger aircraft have fuel tanks in the wings. Why? What are the advantages and disadvantages of this location ? examples of disadvantages I would suspect: added weight increases the structural ...
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2answers
1k views

How is fuel managed in the Zero-G A310?

There are several Zero-G airplanes to experiment briefly microgravity without going into orbit. One is the A310 from Novespace (F-WNOV): Novespace A310 F-WNOV (source: Jonas Wirz at Airplane-Pictures....
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0answers
80 views

What is a possible reason for an L-1011 wing fuel tank overflow? [duplicate]

I was on a TWA Charter flight from Boston to Montego Bay Jamaica in 1989. During pushback from the gate, the right wing began to leak jetfuel (like gallons pouring out of the wing). They stopped the ...
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0answers
88 views

Could injectors be used as an alternative to turbopumps in jet engines?

Could injectors be used instead of turbopumps in aeroengines? Are there jet engimes that already use them? https://en.m.wikipedia.org/wiki/Injector
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1answer
127 views

What's this fuel line for?

Cessna 414 ram conversion What's this fuel line for that is coming to injector , other then the one from fuel disturbutor ?
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2answers
2k views

Why does the cabin air sometimes smell of kerosene? [duplicate]

Why does the cabin air sometimes smell of jet fuel, although bleed air is tapped before it comes in contact with fuel ? How is this possible? I have smelled this a couple of times in my life (twice ...
4
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1answer
458 views

Why do the A320's centre tank pumps stop working 5 minutes after the low level has been reached?

I'm new here and I'm in training course for Airbus A320. In the training material, it's said that the centre tank pumps are controlled to stop automatically 5 mins after the low level fuel has been ...
83
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4answers
17k views

Why do we need to starve the engine before turning it off?

This question is for Piper Tomahawk, but I guess applies to any small aircraft. Why do we need to use the fuel mixture to starve the engine before turning it off with the key? Why can't we just turn ...
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1answer
263 views

Does preheating fuel before it reaches the turbine result in a performance improvement?

Preheating fuel before it reaches the combustion stage was first proposed several decades ago as a way to improve mixture, fuel economy, and to reduce emissions in car engines. One example of this ...
3
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3answers
2k views

Are there any 100% renewable energy aircraft in development?

There seem to be several options for aircraft R&D regarding cleaner fuels for the time when fossil fuels are no longer economically viable. Some of these include: Algae. A drop-in fuel. These ...
11
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1answer
378 views

How do fuel trim and air bubbles prevention work in inverted flight?

I was reading Why do many GA aircraft not have a "Both" fuel selector? and voretaq7's excellent answer got me to thinking. He cites the regulations noting that the plane must only draw fuel from one ...
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6answers
4k views

Is there a tank priority sequence for using the fuel tanks?

Is there a tank priority sequence for using the fuel tanks, or does the pilot decide?
6
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1answer
291 views

Has fuel boiling ever been an issue for high altitude aircraft?

Are special measures being taken to prevent fuel from boiling inside the fuel systems at high altitudes? If so, when (with what aircraft) did this practice start? (question is pertaining to air-...
2
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3answers
355 views

How the fuel in the wings is managed in case of an engine failure?

Consider an aircraft has fuel tanks only in wings (No central tank). Will the fuel for the respective engines will be consumed from the respective wings? In case of a single engine failure, if the ...
5
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2answers
253 views

Could hydrazine be used as a scramjet propellant?

Hydrazine is used a monopropellant in Satellite OMS rockets. But interestingly enough, it's highly exothermic decomposition into ammonia, nitrogen, and hydrogen provides heat for an endothermic ...
1
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1answer
379 views

Hydro-pneumatic fuel controls and hydro-mechanical fuel controls

What are the advantages and disadvantages of the hydro-pneumatic controls against the hydro-mechanical controls?
12
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5answers
5k views

Why is mixture lean recommended on the ground?

Mixture lean is typically recommended during the ground operations at sea-level pressure in the POHs of most small aircraft equipped with a carburetor system. Why is it? I heard some people saying it'...
1
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1answer
884 views

What is the Specific Fuel Consumption of CFM56-7B24/26/27 engines?

I think the title completely says what I need. I use FSX (Flight Simulator X) to simulate flights and while flying the B738 I saw that it consumes much more fuel than the estimated amount, which is ...
71
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6answers
22k views

Why are fuel tanks in the wings filled first, and why are they used last?

When fueling airliners, why is fuel filled first in the tanks in the wings and then the center tanks? And why do they use fuel from the center tanks first and then from the tanks in the wings? From ...
8
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1answer
298 views

Can IPA be used as a FSII with MoGas, particularly with a Peterson STC?

This question established a basis for the use of 100% Isopropyl Alcohol (IPA) as a Fuel System Icing Inhibitor (FSII) in aviation gasoline systems. However, this Cessna Service Letter documents that ...
4
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1answer
935 views

Why does fuel vaporize in the carburetor?

So I get that a carb vaporizes fuel and mixes it with the air intake for the engine. But my question is what is the explanation for what causes the fuel to vaporize after it exits the fuel nozzle?
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0answers
414 views

What is the correct procedure for overwing fueling a CRJ200?

I have a question regarding overwing fueling a Canadair CRJ200. Let's say I was pressure fueling and one of the wings started venting fuel on the ground. The Crew Chief determined that I had to ...
1
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1answer
435 views

Could a kerosene fueled jet engine run on methanol without significant modifications? [duplicate]

Could a kerosene fueled jet engine run on methanol without sacrificing performance other than specific impulse? Would it require changes to the fuel injection/turbopump system? Would the combustor ...
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4answers
5k views

What could the fuel pump failure have been that my flight experienced?

I was on an Easyjet flight (I think an A320), when mid-flight, I overheard a member of cabin crew tell another passenger there was a 'technical' issue with the aircraft, that might make us slightly ...
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1answer
2k views

How does the FAA define fuel capacity for ultralights?

Ultralights under FAR 103 are regulated to a capacity of 5 gallons. I'm wondering how exactly fuel capacity is defined, does it include fuel in the lines, and in the carburetor bowl or elsewhere or ...
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0answers
48 views

How do airblast fuel atomisers work?

How do airblast fuel atomisers work? Do they simply inject fuel with high velocity? Against the flow or perpendicular to it? How is the fuel jet shaped?
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0answers
74 views

What's the difference between “dumping” and “jettisoning” fuel? [duplicate]

There are some countries (Sweden, for example), they do not permit "dumping" fuel, only "jettisoning" procedures. Is there any difference according to the amount of fuel that will reach the ground? ...
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1answer
3k views

Why is fuel used as a hydraulic fluid?

Why is fuel used in some servo-systems as a hydraulic fluid (fueldraulic systems) of modern civil and military aircraft such as the Boeing 777-200/-300 (Pratt & Whitney PW4084) or the Lockheed ...
3
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1answer
511 views

Do Airbus aircraft fitted with ACT have additional fuel system controls?

Do Airbus aircraft fitted with ACT (Additional Center Tank) have a push button that controls the fuel transfer to the main center tank? If yes, where is it located?