Questions tagged [fuel-systems]

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

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Military aircraft deliberate fuel dump capability?

I this question Why would a fighter drop fuel into a drone? it was essentially asked if the SU-27 has the capability to deliberately dump fuel in a controlled manner. My question is if other current ...
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1 answer
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How many fuel vents are there in DA40NG airplanes? (Tank Air Outlet)

How many fuel vents (Tank Air Outlet) are there in DA40NG airplanes? I wonder how many there are under each wing surface. I know that the hole on the round cover we see in the first photo is "...
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2 votes
1 answer
186 views

What is the function of the pipe referred to as "Venting Pipe" in the picture and how is it different from the exhaust pipe?

What is the function of the pipe referred to as "Venting Pipe" in the picture and how is it different from the exhaust pipe? The two photos you see in the picture are the "Venting Pipe&...
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5 votes
1 answer
150 views

Radar fuel level sensor

Do any aircraft use radar to measure the level of fuel in their fuel tanks?
3 votes
0 answers
90 views

Is there any authoritative source where I can find a list of companies producing Sustainable Aviation Fuel in the U.S?

Is there any authoritative source (website, directories, etc.) where I can find a list of companies producing Sustainable Aviation Fuel (SAF) in the U.S? Based on media reports it seems that there are ...
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3 votes
2 answers
287 views

How can I determine the fuel temperature in the tanks of an Airbus A320 during climb?

I know that, for example, at 10000ft the outer temperature is around $-10\, ^\circ\! C$. How can I calculate the fuel temperature in the tanks? In technical notes I find on the internet for Airbus ...
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2 votes
1 answer
105 views

Is more information available about missionary pilot Nate Saint's backup fuel system described in "Through Gates of Splendor"?

I'm currently reading the book Through Gates of Splendor, and at one point (pages 61-63 in the first edition, about halfway through Chapter 5), it describes a system invented by missionary pilot Nate ...
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7 votes
3 answers
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United’s 787-9 upgrade [duplicate]

I read this article about United increasing their performance of the 787-9. More specifically increasing thrust and range, But it says this will be done over software. How do you make an engine burn ...
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1 answer
79 views

Can the ECS pipe/hose run through the aircraft fuel tank?

Hope you can help? We are in the process of redefining aircraft fuel tank and there might be a possibility that we may need to run the ECS (Environmental control system) pipe through the fuel tank? ...
7 votes
2 answers
619 views

What is the role of HP & LP fuel pumps in aircraft?

What is the role of HP (high pressure) and LP (low pressure) fuel pumps in aircraft like the A320? Why are two different ones needed?
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0 answers
60 views

What type of fuel is used for each type of mig-15-29?

What type of fuel is used for each type of mig-15-29? ts-1 t-8v, t6...the same things...
0 votes
1 answer
168 views

Does the fuel selector switch of a Cessna 172 automatically turn 180° when pulling fuel shut off?

I noticed this behaviour in X-Plane 11 using the LR Cessna model and I'm wondering if this resembles the correct behaviour of a real aircraft. Also it seems that in X-Plane after pulling the fuel shut ...
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1 answer
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747 Fuel Drain Ports

I read about the fuel systems on aircraft for a project I'm working on, and I was wondering about the "fuel drain ports" mentioned, which the document stated were used for complete drainage ...
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1 answer
270 views

Understanding fuel tanks/pumps of Fighter jet

I have observed fighter jets performing maneuvers like inverting, Turing around in sharp angles etc. This may subject plane to G forces and other dynamic forces. How does fuel tank ensure steady ...
6 votes
1 answer
1k views

The fuel shut-off valve was left in over night. Is it dangerous for the plane?

I forgot to pull the shut-off valve in my plane (PZL-110 Koliber 150) while I was trying to start an engine. Will this have any effect on the plane? It has a mixture supply knob and is a pull/push ...
4 votes
2 answers
3k views

What is the purpose of the fuel pumps in the A320?

It might seem like a really stupid question, But i'm getting into flying the FBW A320 in MSFS2020 and I have no idea what the fuel pumps are for in the A320, please may someone explain and help a ...
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1 vote
2 answers
170 views

C172N Skyhawk II fuel drain handle operation for people < 180cm

I'm asking for a friend - literally. One of our club's planes is an old workhorse used a lot for training. She's got a fuel drain handle in the inspection hatch where one checks the oil. I've never ...
17 votes
1 answer
2k views

When drop tanks (those with external lines) are released, how are the two connections (air and fuel) released?

ww2aircraft.net Say in a P-51 (shown above), when drop tanks (those with external lines) are released, how are the two connections (air and fuel) released? Do they shear off and fall with the tank? ...
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3 votes
2 answers
213 views

Where is the ram air inlet duct on the A220 for the fuel inerting system? Is it the same duct as the air conditioing?

Title says it all... just trying to find out if there is a second NACA duct for the fuel inerting system on the A220, or if it's the same duct that is used for the air conditioning inlet.
8 votes
2 answers
870 views

Why does a fuel-injected engine have a mixture control?

For example, in a C172S fuel injected type, what does the mixture control lever control exactly in the fuel system? They have a fuel air control unit which regulates fuel flow based on air passing ...
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12 votes
6 answers
6k views

Does this fuel leak from the carburetor of a Cessna 172E need immediate maintenance?

Consider: I'm concerned with a fuel leak I've developed on my Cessna 172E in the past three weeks and appears to be coming from the carburetor. There is even some fuel in the air breather near the ...
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9 votes
2 answers
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How common were (are?) hydraulically driven fuel pumps?

The XB-70 had a large number of fuel transfer pumps (something like 25) to transfer fuel from the 10 other tanks into the sump tank, and then three fuel "boost" pumps to pump it from that to ...
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6 votes
2 answers
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How does a fuel density sensor work? (densitometer, cadensicon)

While some fuel volume sensors use ultrasonic measurements this answer to How is fuel mass measured in airliners? says: The FCOM lists the sensors involved in this measurement: The FQI system ...
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16 votes
2 answers
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How is fuel mass measured in airliners?

Large airliners display the amount of fuel in each tank as a mass (usually in kg or lbs) and not as a volume. This makes sense since mass is important for weight&balance considerations and the ...
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4 votes
2 answers
769 views

On what basis is the weight unit of the FQIS selected by airlines of various countries?

On what basis is the weight unit of the FQIS (Fuel Quantity Indicating System) selected by airlines of various countries? Does it depend on the local country for using imperial or metric units?
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Why are there motive flows for the turbine pumps of Williams International FJ44-3A engine?

For my university project, I am designing the fuel supply of an aircraft using a Williams International FJ44-3A engine. Studying the related FAA TCDS, I read "Fuel from the motive flow port on ...
1 vote
1 answer
223 views

What are the fuel system pressure and temperature requirements of a Williams FJ44 engine?

For my university project, I am designing the fuel supply and control system of an aircraft that use Williams International FJ44-3A engine. However, after scouring through its type certificate ...
2 votes
2 answers
652 views

What is vapor lock?

Vapor lock occurs in piston engines especially during summers.. before starting engine we prime it and the engine starts but as soon as we reduce it to near idle or just above idle, engine tends to ...
1 vote
0 answers
192 views

Where are the small fuel reservoir tanks on a Cessna P210N?

I have looked through the POH and the maintenance manual of the Cessna P210N, both said that the fuel goes from the main tanks into two small reservoir tanks somewhere on the lower side of the ...
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7 votes
3 answers
1k views

Why do we turn on fuel pump before descent in Diamond DA40?

The checklist procedure is: Electric fuel pump ............. on Mixture ............. rich MAP ............. 15 in of Hg RPM ............. 2300 Why the AFM says to turn on fuel pump during descent ...
0 votes
1 answer
182 views

How should fuel go through pumps?

I understand that in the fuel system of an aircraft, the fuel first go through wobble pumps--manually driven, and then fuel strainers--for filtering out debris, and finally the engine driven pumps. ...
9 votes
3 answers
3k views

Do pilots need a fuel pressure/temperature gauge?

Fuel pressure gauge allows you to monitor the fuel pressure while the engine is under a load. However, since the fuel pressure requirement is listed by the engine manufacturer, do pilots even need a ...
0 votes
1 answer
138 views

What extra components does a fuel tank have?

For small-to-mid-size aircraft like V-280, and gulfstream aircraft, what component does their fuel tank has when it arrives for assembly? Is it just a metal box with valves? Or it contains heating ...
0 votes
1 answer
146 views

Who make the fuel system, cabin pressurization system, and firefighting system?

Who makes the fuel, cabin pressurization, and engine firefighting system for an aircraft with engines on, or in, the wings? Fuel tanks and fuel pipes, pressurized air pipes and heat exchanger, and ...
4 votes
2 answers
665 views

Why should the fuel shutoff valve in a Zlin Z-142 not be set to both for takeoff?

The fuel shutoff valve in the Zlin Z-142 has four different positions: Off, Left, Right and Both (L+R). In the POH, the procedures related to normal flight operations, suggest that during taxiing and ...
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1 vote
2 answers
2k views

Is it generally acceptable to use 100LL and 100 grades of AVgas mixed into the same tank?

Is it acceptable to use 100LL and 100 grades of AVgas mixed into the same tank, or should one type of fuel be drained prior to addition of a mismatched type? This is assuming the aircraft is approved ...
2 votes
2 answers
533 views

Use of a solenoid valve over a selector valve

When designing a low-wing light aircraft with two integral tanks at the wings and a collector tank in between, what type of valve should be used to allow the pilot to select the integral tank which ...
2 votes
0 answers
146 views

Overheating (fire thrown out of the nozzle) [closed]

At first I copied https://www.jetcat.de/en/productdetails/produkte/jetcat/produkte/hobby/Engines/P160_rxi_b Where I manufactured and installed all the parts and they are very similar to the original ...
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1 vote
0 answers
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When should the fuel pump be on in a Cessna 152? [duplicate]

I am a new student and just need help understanding the fuel pump system. For a Cessna 152, in which scenario would I have the fuel pump on ? Start ? After Start ? Before Take-Off ? After Take-Off ? ...
5 votes
1 answer
941 views

How does a hot tip-jet supply fuel to its engines?

Some tip-jets move their rotors by running jet engines on each end of the rotor. Obviously there must be some ways to supply fuel to those engines through a rotating body. How is this accomplished?
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10 votes
3 answers
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Why don't all cylinders have priming lines?

Questions about the primer for carburetor engines. Why does the primer only spray fuel to three (sometimes just one) of four cylinders. (Like Piper Cherokee or Seminole) And is it true that priming ...
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3 votes
4 answers
977 views

What are some symptoms of a clogged fuel filter?

I can certainly imagine one of the symptoms could potentially be engine fuel starvation. If the fuel flow to the engine isn't totally blocked, how can one recognize a clogged fuel filter?
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3 votes
2 answers
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What is the difference between LP fuel valve and LP fuel shut off valve?

In the Airbus A320 FCOM in some places "LP fuel valve" is mentioned (in Fire and Fuel System chapters) whereas in the engine chapter "LP fuel Shut off valve" is mentioned. Is there ...
14 votes
2 answers
3k views

Why nitrogen generation system is only present in centre tank only?

I was going through FCOM of A320 and it mentioned that nitrogen generation system is only there for centre tank and not for wing tanks what is the reason for the same?
2 votes
2 answers
560 views

Is gascolator and fuel strainer the same thing?

I am wondering is gascolator the same as fuel strainer, or this two things are bit different. Because sometimes I see one term, sometimes another, and I don't know if I am reading about the same thing....
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1 vote
0 answers
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What is a typical fuel temperature entering the burner for different mission flight points of a civil aircraft?

Is there a target regarding the fuel temperature that enters the turbine engine's combustion chamber and if so does it change with different operation flight points in civil aircraft applications? Is ...
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1 vote
1 answer
117 views

How long would the engine of a Tecnam P92 Eaglet run for with the fuel selectors turned off?

I'm wondering about a scenario where a P92 has been flying for at least 30 minutes or so, at say 4,000 RPM and 2,000' AGL at standard temperature (I'm not sure if these details matter). With both ...
0 votes
1 answer
153 views

How do fuel tanks prevent free surface effect? [duplicate]

Free Surface Effect is a fancy term that refers to liquids changing their relative orientation within a container, whenever the container is rotated. So imagine a large plane banking very steeply, at ...
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16 votes
4 answers
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Why do jet engine igniters require huge voltages?

Wikipedia's Components of Jet Engines has this to say on the igniters: A high voltage spark is used to ignite the gases. The voltage is stored up from a low voltage (usually 28 V DC) supply provided ...
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17 votes
5 answers
6k views

Why aren't "fuel polishing" systems removing water & ice from fuel in aircraft, like in cruising yachts?

Should you sump fuel tanks when the fuel system is below freezing? the question should one sump fuel-tanks before flying, if in freezing-conditions? but this implies another question that boggles me:...