Questions tagged [fuel-consumption]

The amount of fuel an aircraft burns during a specified time period or for a specified distance; also known as "fuel burn".

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Am I calculating the fuel consumption correctly?

I'm trying to calculate the fuel consumption for l550e engine. In its datasheet you can see this graph: At 6500 RPM, engine power is around 48hp and the SFC is 345g/HPh. Ok, then the fuel consumption ...
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How did the 767/757 reduce fuel burn relative to older aircraft (like the 727)?

When Boeing launched the 757 and 767 aircraft, they widely touted it's improved fuel efficiency relative to previous airliners. Notably: Delta stated that the 767 was "quieter and 30 percent ...
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18 votes
5 answers
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Would an airliner climb higher late in the flight because of the consumed fuel (lighter airplane) to save more fuel?

Some people said airplanes would fly higher in the late period of each flight, because the fuel is consumed, and the airplane is lighter. Higher altitude and less dense air is enough to support the ...
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Is this concept of a hybrid between a Turbine Engine and a Reaction Engine (Rocket) practical? [duplicate]

So, I don't understand much about engineering in general, but since this is a discussion forum, I like to think that this is just a thought exercise (because it is probably useless). So, the idea ...
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2 votes
1 answer
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How far could a KC-10 tanker fly if it consumed all of its internal fuel tanks?

I have read that the KC-10 tanker aircraft carries a maximum load of 356,000 lbs of fuel. It also consumes the same fuel that it carries for refueling other aircraft. So naturally, I am wondering: If ...
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2 answers
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Does endurance include the fuel reserve time?

I have been wondering if endurance time actually includes the fuel reserve time? For example: Total usable FOB = 84 litres Fuel burn rate = 16 litres/hour Aircraft's reserve fuel = 30 minutes ...
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19 votes
1 answer
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Why is the 777 fuel burn rate graph U shaped and skewed to the left?

I don't know math or physics. If I misuse terms, just edit my post, thanks! Presuppose a normal uneventful flight, such that as the plane climbs and cruises, the pilot reduces engine thrust to 69%-...
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7 votes
1 answer
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Why is my calculated seat-miles per gallon of small aircraft higher than of big aircraft?

I've calculated the seat-miles per gallon for three planes. This factors in the speed; it basically means how much does it cost to transport 1 person 1 mile. Plane Seats Cruise (MPH) gph seat-mpg ...
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1 vote
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Why doesn't the -30% SFC fully account for the dramatic reduction in fuel consumption compared to the 1960s?

In looking at the specific fuel consumption (SFC) of some aero engines I find that for example, the Rolls Royce Conway turbofan engine had typical cruise SFC of 0.874 lb/(h lbf) whilst the most modern ...
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9 votes
1 answer
358 views

What is the function of the aft stator in CFM's open rotor engine design?

CFM revealed their design for a open rotor propfan engine with two stages of blades - one active set of blades rotating in the forward and an static sets of blades on the aft. According to The ...
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1 vote
1 answer
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What's the optimal cruise lift to drag ratio of the Piaggio Avanti?

I'm interested in the maximum L/D this plane can achieve. I can't find the necessary data to do the calculation myself. If I knew the "long range cruise" engine power and assumed 85% ...
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1 vote
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320 views

Is the FF (Fuel Flow) the fuel consumption index?

I am creating a program to calculate the fuel needed to fly and I need to know the fuel cost of the plane. In the boeing 737-800 (PMDG), on the display that shows the plane's systems, there is the FF (...
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1 vote
1 answer
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What factors cause a turbine aircraft to have decreasing fuel burn over time?

Consider a fictional aircraft with a fuel schedule similar to the following: ...
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What is the fuel burn rate for climb of a C-130J Hercules?

I am trying to graph the payload range for a C-130J Hercules and I need an approximate value for fuel burn rate which I cannot seem to find online. Does anyone know approximately how much fuel a C-...
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What is the fuel burn of the APU on the CRJ900?

Looking for a reference from an FCOM, AFM or other manual for the fuel consumption per hour in pounds or kilos of the Honeywell RE 200 APU on the CRJ900.
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-1 votes
4 answers
283 views

How do jet streams affect the fuel consumption?

I am trying to wrap my head around the effect of the jet stream on energy consumption as well as flight time. My understanding is that everything that has to with the flying part (vs navigation) ...
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6 votes
1 answer
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What are the engine-out implications of giant turbofans?

It seems that turbofans for civil airliners are improving fuel efficiency by building larger and larger fans that spin slower. For example, the RR Trent 800 introduced in 1993 had a diameter of 2.8m, ...
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Why are F-15s usually taking off with afterburners?

If there's no emergency, is it a big waste of money for military aircraft to take-off with afterburners? Why are they doing it, what are the advantages? Like here:
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2 answers
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Does airspeed impact fuel flow?

Let's say an F-104 Starfighter is flying at sea level at 600 KIAS with throttle at 100% RPM. Then, let's say the F-104 is still flying at sea level, but the pilot reduces throttle and airspeed falls ...
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2 answers
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What is the fuel consumption per mile for a full CEO A320?

I’m writing an essay as part of my GCSE HPQ and one of the statistics I need to base my research and answer on is the fuel consumption per mile or kilometre for a CEO A320. It doesn’t have to take ...
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Can thermals or high density altitude improve fuel efficiency?

Suppose a pilot is just cruising around building flight time. In order to get the most flight time for fuel, would flying on a dry cold day or on a hot thermal filled day save fuel?
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16 votes
3 answers
2k views

Can the plane Celera 500L be eight times more fuel efficient than a jet of similar size and capacity?

Celera 500L (see Otto Aviation site for more details) is a plane with a single propeller powered by a piston diesel engine. The constructor claims it is 8 times more fuel efficient than a jet of about ...
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1 answer
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How do I find out the fuel consumption of the PT6A for a lightly loaded aircraft?

The Fuel consumption of PT6 engines provided by manufacturers are as follows. Cessna Caravan - Consumption ~47? GPH. At full load at ~160? Kn. Quest Kodiak - Around 49 GPH at full load at ~170 Kn ...
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What is the ground idle fuel flow of an A320 (CFM or IAE or neo)?

Standing on ground, what is the idle fuel flow of an A320? ISA conditions, both engines running?
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Has there been any attempt to use an underground cable system, a la a cable car, to tow aircraft along taxiways? [duplicate]

I've been looking at some proposals to try to reduce the time that an airliner's main engines are run at idle or near idle when taxiing to and from runways--a situation that uses non-trivial amounts ...
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1 vote
2 answers
171 views

Was it ever considered to optimise a jet to normally operate with one engine shut off?

As I understand it, the current trend to reduce all commercial aircraft to no more than two turbofans has long-relevant reasons – the more engines, the higher the fuel consumption – and earlier jets ...
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2 votes
1 answer
549 views

Why is the thrust-specific fuel consumption much worse for high bypass turbofans at cruise?

General Electric GE90 Takeoff: 0.278 lb/lbf/h (28.3 kg/kN/h) Cruise: 0.545 lb/lbf/h (55.6 kg/kN/h) Source: https://en.wikipedia.org/wiki/General_Electric_GE90#Specifications I assume this is typical ...
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3 votes
2 answers
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How does fuel economy quantitatively depend on altitude for a jet?

We already have a few questions and answers about the qualitative effects of altitude on fuel economy: How do I determine the best altitude to fly for fuel economy? Why does fuel consumption decrease ...
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2 votes
3 answers
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Which is more efficient: a jet engine or a rocket-powered engine?

Knowing that rocket powered engines have higher speeds than jet engines, it raises the question: are jet engines more efficient than rocket powered engines? This is of course in terms of fuel ...
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3 answers
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Why do turbofans go faster than turboprops? [duplicate]

Can someone explain why turboprops are less effective in terms of thrust than turbofans? But at the same time, why turboprops burn less fuel? For example, the Bombardier Q400/De Havilland Dash 8 has a ...
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5 votes
1 answer
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Why use thrust reversers? [duplicate]

I see a lot of planes using thrust reversers and stopping in the middle of the runway in plane spotting videos, but I don't understand why they do it when they can obviously not use the reversers and ...
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18 votes
1 answer
4k views

Why would a B-29 consume more fuel at 17 kft than at 9 kft?

According to Wikipedia, one of the factors which almost caused B-29 44-27297 (Bockscar) to run out of fuel and crash at the end of its 9 August 1945 strike mission was the selection of an excessively ...
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8 votes
3 answers
474 views

Is it possible for a plane to be over fueled (and over-weight) to take off?

I've just reached my destination after 33 hours going from one European hub to another. A journey which usually takes a max of 6 from leaving my house! On the final leg of the journey, after boarding,...
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1 vote
0 answers
83 views

Fuel quantity vs. range

I'm just a Flight Simulator player with no real-life flying experience, so I apologize in advance if I'm asking a stupid question :) I watched a TV show and saw that certain courier companies (DHL ...
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3 votes
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Are measures taken to deliberately increase the fuel burn rate to lower the landing weight? [duplicate]

Just recently the Air Canada flight AC837 from Madrid to Toronto had problems with the gear right after take-off and they decided to abort the flight and go back to Madrid. It was a B767-300 (C-GHOZ) ...
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Average weight of fuel required to carry 1Kg additional cargo weight per hour [duplicate]

I'm looking for an average number here, I know there is not one correct answer as there are many parameters to take into account. Alternatively, I could also use something different, like : how many ...
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1 vote
0 answers
119 views

Fuel consumption database using ICAO codes?

I will preface this by saying I do not have any level of knowledge in Aerodynamics - I'm a freelance journalist and so apologies for the poor level of general understanding. I'm attempting to create ...
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3 votes
2 answers
282 views

Does burning fuel to get to your max landing weight violate any regulations?

Consider a hypothetical situation where where an unexpected tailwind will cause a flight to arrive at its destination above maximum landing weight. After reviewing all reasonable changes to altitude ...
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1 vote
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What is the specific consumption of an A320 at Mach 0.78 and 11,000 metre altitude? [duplicate]

I am currently doing a dissertation on an electric drive system on planes and I need help. I can't find the specific fuel burn rate for an Airbus A320; if anyone could help it would be great. Also a ...
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0 votes
1 answer
1k views

Turboprop vs Turbofan: How to compare Specific Fuel Consumption

I understand that Turboprop engines have a lower Specific Fuel Consumption (SFC) than Turbofan engines, on average. I want to see this for myself by analysis, ideally by comparing values of SFC for ...
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0 votes
1 answer
374 views

Why are there no large turboprop passenger airliners? [duplicate]

If turboprop engines are more efficient than turbofan/jet engines at lower speeds, and have a lower specific fuel consumption, why are there no large passenger airliners that utilize the turboprop ...
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2 votes
1 answer
974 views

What is the range difference between LEAP and PW1000 powered A320 and A321 NEOs?

Mounted on the same aircraft, PW 1000G and CFM LEAP are two very different engines, with different performances, that should have an impact on range. And we know range is a very important aircraft ...
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1 vote
0 answers
75 views

Do winglets really improve efficiency and reduce drag? [duplicate]

Below are some pictures of various fixed wing aircraft with winglets. It is widely accepted that these winglets will improve an airplane's performance by reducing drag and therefore improving fuel ...
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4 votes
2 answers
292 views

What is a jet engine's fuel flow at constant IAS?

Here is my assumption: In straight and level flight of a jet turbine engine: One IAS = One drag = One thrust = One fuel flow Therefore, the fuel flow will be approximately the same for a given IAS, ...
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-1 votes
2 answers
15k views

What is the typical fuel consumption of a 737 in MPG?

What is the typical fuel consumption of a Boeing 737 in MPG?
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6 votes
1 answer
438 views

Does one-engine cruise consume less fuel than two-engine cruise?

Scenario 1. A two-engine airliner experiences rapid depressurization and makes an emergency descent to 10,000 ft, and diverts to the nearest airport. Scenario 2. The same two-engine airliner ...
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4 votes
3 answers
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How much does it cost extra to fly with one additional passenger?

How much does it cost to fly an airplane (like a Boeing or Airbus) when there's one extra passenger there, at an average speed of 475–500 knots (880–926 km/h; 547–575 mph)? That is, about 100kg extra,...
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12 votes
10 answers
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What is the most 'environmentally friendly' way to learn to fly?

As this question indicates, I've been thinking recently about the environmental impact of flying (since when automated cars are the only means of ground transport, aviation will be responsible for ...
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24 votes
9 answers
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What is more environmentally friendly? An A320 or a car?

Presuming the A320 is at least 80% full (of passengers) and comparing it to a typical road car with 2 people inside, which one is more environmentally friendly, per passenger mile? I have attempted ...
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1 answer
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What exactly do winglets do? [duplicate]

I know that the winglets on planes like the Boeing B737 and Embraer E-190 reduce fuel consumption, but do they do more than that, or are they just for the stated purpose?
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