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Questions tagged [fuel-systems]

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

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3 votes
1 answer
148 views

How long can a turbine-engined aircraft be left fuelled?

Presumably, if one is going to be keeping an aircraft on the ground for a long time without running the engines or the APU, the aircraft's fuel tanks will need to be drained and purged... ...to ...
0 votes
1 answer
113 views

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 "...
1 vote
1 answer
208 views

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 ...
2 votes
1 answer
193 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&...
5 votes
1 answer
153 views

Radar fuel level sensor

Do any aircraft use radar to measure the level of fuel in their fuel tanks?
3 votes
0 answers
92 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 ...
3 votes
2 answers
321 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 ...
9 votes
1 answer
3k 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?
2 votes
1 answer
109 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 ...
7 votes
3 answers
1k views

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 ...
0 votes
1 answer
85 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
840 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?
1 vote
1 answer
163 views

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 ...
3 votes
2 answers
257 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.
0 votes
0 answers
70 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
185 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 ...
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 ...
0 votes
1 answer
314 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 ...
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 ...
1 vote
2 answers
194 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? ...
2 votes
1 answer
337 views

How much pressure do boost and jettison fuel pumps produce?

What is the pressure output of a (boost) fuel pump on a Boeing 767 and/or 777, compared to a heavy-duty jettison fuel pump.
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 ...
57 votes
4 answers
12k views

Why do many GA aircraft not have a "Both" fuel selector?

I've been trying to rack my brain around this and asked a few CFI's who couldn't give me more than "because that is how it was done", but a good number of GA aircraft save for Cessna and maybe a few ...
8 votes
2 answers
1k 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 ...
9 votes
2 answers
1k views

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 ...
3 votes
1 answer
2k views

How does this fuel pump work?

This question is about the fuel pump controlled by the hydro-mechanical fuel control unit. This is part of a fuel system for a turboprop engine, described on this page which actually comes from a ...
6 votes
1 answer
4k views

Where is the fuel vent on a Piper Archer TX?

I realized I haven't really noticed where the fuel vent is for the 2016 Piper Archer TX that I've flown, but I assume the fuel is vented from the fuel cap. Is that correct?
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
214 views

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
237 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 ...
6 votes
2 answers
2k views

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 ...
4 votes
2 answers
782 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?
16 votes
2 answers
3k views

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 ...
2 votes
2 answers
804 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
199 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 ...
4 votes
2 answers
667 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 ...
0 votes
1 answer
185 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
140 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
147 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 ...
16 votes
4 answers
12k 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 ...
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
547 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
155 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 ...
1 vote
0 answers
65 views

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 ? ...
27 votes
4 answers
12k views

Why are the center tank pumps deactivated when slats are extended on the A320?

Why are the center tank pumps deactivated when slats are extended on the A320? I researched about this and all I can see is hints. They say it is because of regulations or certifications.
5 votes
1 answer
954 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?
10 votes
3 answers
1k views

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 ...
15 votes
5 answers
7k 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 ...