Questions tagged [fuel]

Different aircraft engines use different fuels; the most common types are Jet A or A-1 for jet and turboprop engines, and avgas for piston engines.

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40
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5answers
94k views

What are the differences between fuel types (comparing with vehicles)?

I find it funny that at gas stations, generally you can purchase "regular" gasoline (in various octane levels) or diesel. At airports, generally you can purchase 100LL avgas or Jet-A. Can you compare ...
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What are the ICAO fuel reserve requirements?

How much reserve fuel are private and commercial aircraft required to carry by ICAO rules? I heard that it changed recently (about a year ago) and is a little complicated. How is it calculated for ...
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Why does the F-111 sometimes squirt a giant fire plume behind it? (NOT afterburners!)

As seen in multiple pictures: First, this one, it appears the aircraft is spraying copious amounts of fuel into the exhaust! Surely this provides no thrust, not in the way an afterburner (which the ...
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6answers
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Why do jet engines use kerosene rather than gasoline?

Could you run a jet with gasoline? Why do all jet engines use kerosene?
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Which engine is more efficient between turboprop vs jet?

Are turboprops really more efficient than jets? If yes, does that mean that airlines who use jets sacrifice fuel for faster flights?
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1answer
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What is the cost savings of using electronic motors to taxi?

Aircraft manufacturers are now planning to use High Torque electric motors on the nose wheel of the aircraft, which is powered from the APU, to taxi the aircraft from the gate to the runway without ...
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2answers
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What happens to incoming flights when the airport shuts down?

In Die Hard 2 terrorists take over an airport's ILS and landing lights on a snowy night (visual landing is impossible) and start making threats essentially holding the planes hostage. The tower ...
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1answer
959 views

Are there any programs to build a hydrogen powered airplane?

So called "renewable energy" is a buzzword these days. Auto manufacturers are starting to roll out hydrogen powered cars. Hydrogen may not currently be the most efficient or economic fuel for jet ...
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How much fuel does it take to start/land an aircraft, compared to normal flight?

I'm wondering how bad it is to fly a short distance, such as ~50km, with a big airplane. How much less fuel does it take to fly at high altitudes compared to low? And how much of the fuel is spent on ...
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Why are piston engines for aircraft rarely diesel powered?

Why hasn't diesel caught on much for aircraft engines? The list of diesel aircraft engines on Wikipedia is very short. The reason I see mentioned is their poorer power-to-weight ratios. (e.g. What ...
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At what point during a long flight do commercial airliners have the best gas mileage?

This question has several parts that are interrelated, and I didn't want to split it up: Considering that several tons of fuel are consumed during a long haul flight which requires lift to be reduced ...
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How do aircraft keep fuel from freezing while in flight?

On aircraft which fly above 30,000 feet, the temperature can often can get to temperatures below Jet-A's freezing point. For example: at 36,000 feet the standard outside air temperature is -56.5°C (-...
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Could most commercial jet engines today run on ethanol without any problems?

Most commercial jet engines today would be those large jet engines on large passenger craft like a Boeing 747. Can these run on straight ethanol without any problems? Would more maintenance be ...
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3answers
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What are the concerns and consequences of an overweight landing?

If a 777 ER has to immediately land after takeoff on a planned 14,594 km trip (in the case of a fire, e.g.), the landing will be executed with a very heavy aircraft. What are the major concerns of ...
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4answers
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Do I have to declare an emergency if I cut into fuel reserves?

In another question, I wrote You only need to plan for regulatory reserves. You don't actually have to land with them and @Jan replied: you have to declare emergency if you do cut into them ...
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1answer
723 views

Why might a passenger jet fly at altitudes in a strong headwind when the winds are more favorable at a different altitude?

I was a passenger on an east to west flight recently. During the flight I was playing with Garmin Pilot's new "Flight profile" feature that nicely shows the wind speeds at various altitudes, and I ...
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Do fighter jets have a traditional inverted fuel system?

Common solutions for aerobatic piston singles is to have either header tanks (for wing tanks, as I understand it) or flop tubes (for fuselage tanks). Do fuel systems in a fighter jet work on the same ...
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What is the relation between drag and weight?

Given an aircraft type and fixing its wing configuration (flaps, slats) and fixing its speed and altitude and assuming it flies horizontally, what is the relationship between the aerodynamic drag and ...
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2answers
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How much fuel is used for the different phases of the flight of a typical airliner?

An Airliner flies from LA to JFK in 5 hours. In the first 30 minutes the plane climbs to about 30,000ft. For the next 4 hours the plane flies at about 30,000ft. For the next 30 minutes the plane ...
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3answers
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Why is AVGAS so much more expensive than car gas?

Why is 100LL so much more expensive than gasoline for cars? I get the fact that it's 100LL, instead of 87, 91, etc. For example (as of now, 13 Oct 14), the 91 unleaded gas at my local gas station is ...
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1answer
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How is fuel stored and routed on a trijet with one engine at the tail?

This question pertains to trijets with two engines on the wings and one at the tail, like the Lockheed Tristar. It does not pertain to trijets with all engines at the tail, like the Tu-154. (And it ...
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2answers
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Under what conditions are passengers required to take precautionary measures during refueling?

I was on a recent flight with a fuel emergency, during which the passengers were required to take precautionary measures. Under what circumstances are the precautionary measures mentioned below ...
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2answers
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Does the APU consume a lot of fuel compared to a jet engine?

I would like to know whether the APU of modern commercial airliners consumes more or less fuel than a jet engine. Of course, this will vary between aircraft types, so what comparisons in fuel usage ...
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Why are we still putting lead in our fuel?

Lead in gasoline for automobiles has been banned from nearly every corner of the world, with most bans dating from the nineties. Why are we still poisoning ourselves with lead in Avgas? I understand ...
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6answers
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Why is water-contaminated fuel bad, but water-injection is not?

A "wet" takeoff of a KC-135 with J57 engines—By USAF Photographer (USAF photo) [Public domain], via Wikimedia Commons Why is water-contaminated fuel bad, but water-injection is not? The way I ...
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Do aircraft use the majority of their fuel to overcome friction?

It was asserted (tangentially) in this question that airliners use most of their fuel to overcome frictional losses. Is that a true statement? If so, ...
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3answers
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Why don't we see business jets with wingtip fuel tanks anymore?

There is something I miss from the Learjet 35 (one from FS95/98) that I don't see any more: Fuel tanks on the wingtips! What happened to the wingtip integrated fuel tanks in the business jet industry?
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3answers
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Can a commercial airliner be too heavy to take off?

According to this question's answers, MTOW (or MTOM) is the Maximum Take Off Weight, which is everything up to and including trip fuel. Then there is one step above that, MRW, or Maximum Ramp Weight, ...
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How does the efficiency of a fixed wing compare to a rotary wing?

Is fixed wing more efficient than rotary wing? If yes, why is that?
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What is a (rough) rule of thumb for calculating fuel consumption in a modern jet airliner like Boeing 737 - 300?

I'm wondering what would be a rough rule of thumb for calculating the fuel consumption of a modern airliner like a Boeing 737 - 300. I am not asking for anything from the plane's manual or even a ...
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Why do commercial airplanes smell like fuel smoke before take off?

Why does the cabin of commercial airplanes always smell like fuel smoke coming out from the internal ventilation a few minutes before taking off, I think when the pilot puts thrust into the engines ...
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Did any Boeing 787 operator achieve the 20% fuel efficiency improvement over the 767?

Is there any airline which are able to get the complete 20% fuel efficiency on their 787 with respect to 767 it is going to replace, as told by Boeing. I have read that one of the early customer like ...
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How does flight duration affect the hourly fuel consumption in heavy aircraft?

A 15 hour flight across the Pacific obviously requires more fuel than a 7.5-hour transatlantic flight. How significant is the hourly fuel consumption increase due to the additional fuel carried at ...
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Where I can get historical jet fuels prices?

I would like to analyze jet fuels prices in 2014. Where can I get jet fuel prices for 2014, only in USA and Russia? As there are different types of fuels, it would be okay to get prices for one (...
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How do I determine the best altitude to fly for fuel economy?

If you fly low, air is dense so you can get more thrust from your engines, but you get more drag. On the other hand if you fly higher you have less drag but the output of engine decreases as well. So ...
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Where can I find accurate information about fuel efficiency of Airbus vs. Boeing planes?

I am trying to understand the competitive positions of Airbus and Boeing's large civil aircrafts. I would imagine fuel efficiency would be very important to airline given its large component in the ...
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What were the effects of the oil crises on the Concorde ticket prices?

One of the things that is considered to have greatly hampered Concorde's success were the dramatic oil price increases due to the 1973 oil crisis (the 1979 one surely didn't help either, but it was ...
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Why is fuel usage discussed per time, not per distance?

I don't understand why sometimes the fuel used for a flight is discussed in terms of fuel used per time. I think I have seen it a couple of times here - not sure whether it was in some common context. ...
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Why shouldn't you use HF radio while refueling?

FCOM limitations for many aircraft state: DO NOT USE HF RADIO WHILE REFUELING Why is this? I have heard from people that it's because most of the big airliners have a 'notch' antenna for HF; it's ...
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Why do military aircraft use a different kind of aviation fuel?

Regular airliners use JET A-1 fuel. However, I've seen that military aircraft, i.e., Airforce or Navy; use a different kind of fuel called JP-N, where N is a number. What is the reason why this ...
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1answer
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What are possible explanations for fuel being expelled in this video?

In another question, I asked about whether or not a fuel spill would be reportable or not. The answer was "no", because the aircraft was not in flight. What are the possible causes of the spill ...
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Can a Diesel Aircraft engine be run on Car Diesel?

What are the operational differences between normal diesel fuel used in cars and the Jet-A diesel type fuel used for some prop aircraft such as the Diamond DA62? I know that aircraft use Jet-A fuel, ...
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Would it be feasible for a typical passenger jet to carry along its own Oxidizer?

We know that many Space Shuttles / Rockets etc. carry their own oxidizer with them. This is partly because at the heights they operate the atmosphere is too rarefied to have enough oxygen to sustain ...
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How much fuel do the new A320-Winglets burn vs. the B737-800?

Now that the new A320-Winglets have established themselves, I'm wondering if they have better fuel consumption than the B737-800? I was told that Boeing used to be marginally better. Is that still ...
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Is fuel moved around during flight on a passenger or cargo plane? If so why?

Is fuel moved around during flight on a passenger or cargo plane? If so why? Is balance an issue?
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Why is jet fuel cheaper than piston fuel?

Why is Jet-A cheaper than 100LL? Shouldn't it be the other way around?
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When is a fuel pump needed on GA aircraft?

When is a fuel pump needed on GA aircraft? I am a flight simmer and have noticed that you can leave the fuel pump off and start/fly the aircraft. When would you use the fuel pump?
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Do airplanes dump fuel before landing?

Presumably planes aren't completely empty of fuel when the land, so they don't start refueling from zero, is that right? Is it true that they must dump excess fuel before they land? How much? ...
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How does new media streaming technology equate to fuel cost increase?

In regards to this article on BBC, which discusses the use of streaming technology to allow passengers to watch films/TV shows etc. on their portable devices, the following statement caught my eye: ...
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How much time it will take a B787 to fuel completely when empty?

When a big jet like B787 needs to be fueled with empty tanks, ideally how much time it will take to go full?