52
votes
Accepted
Why is the 777 fuel burn rate graph U shaped and skewed to the left?
What does the graph show?
The graph plots the average fuel required per distance as a function of the total flight distance. It does not show fuel flow rate as a function of time during the flight.
...
- 54.3k
48
votes
Has a plane ever run out of fuel while taxiing?
I saw this happen one time. A DC-3 pulled up to a flight school's pump because no one else had gas. The flight line kid dutifully pumped x gallons into the tanks, but didn't verify with the dipstick. ...
- 12.6k
34
votes
Does a 120cc engine burn 120cc of fuel a minute?
This is possible, but still quite extreme fuel consumption.
120ml == 120cc gasoline are ~90g by mass
90g gasoline need about 1320g air in order to fully combust
1320g air are about 1.08 cubic meters ...
- 1,182
34
votes
Does flying slower actually save fuel?
Yes it saves fuel, unless you get really slow (well below cruise speed - more later.)
Since drag (and thus power required) increases with the square of velocity it will save fuel for the total flight. ...
- 19.4k
29
votes
What is more environmentally friendly? An A320 or a car?
I'm going to simplify and assume that jets and cars burn the same fuel, and output the same exhaust, CO2, NOx and all. I'm going to compare only short-haul flights against cars.
According to ...
- 11k
27
votes
Why cruise at 7000' in an A319?
The only reason for your flight to operate at such low altitude is because it is cheaper for them to do so.
As you said it is due to weather, other route/altitude may not be available. They can ...
- 8,070
26
votes
Does a 120cc engine burn 120cc of fuel a minute?
No, a 120cc engine does not burn 120cc of fuel per minute. It means that the sum of the volumes of space swept by the pistons in each of the cylinders equals 120cc. This is called engine displacement....
- 6,564
24
votes
Accepted
What is the most 'environmentally friendly' way to learn to fly?
Here are some options for flying in an environmentally friendly way:
Use an electric trainer: Since last year the all electric trainer aircraft Pipistrel Alpha Electro has FAA certification. Assuming ...
- 54.3k
21
votes
Can the plane Celera 500L be eight times more fuel efficient than a jet of similar size and capacity?
tl;dr: L/D of the airframe and specific fuel consumption of the engines are credible but that doesn't add up to the claims made regarding fuel consumption and speed relative to jets. Laminar flow ...
- 230k
21
votes
Which engine is more financially economical to operate, a turboprop or gasoline engine?
Piston engines are significantly less expensive to operate, as long as the aircraft's performance and reliability requirements can be satisfied by a piston engine.
It's not just the fuel, it's the ...
19
votes
Has there been any attempt to use an underground cable system, a la a cable car, to tow aircraft along taxiways?
Way to go on thinking outside of the box. Actually, it might work. Although the logistics of it are above my pay-grade. Maybe, some smart group out there could make it work.
But, your question doesn’t ...
- 16.5k
16
votes
Accepted
Why cruise at 7000' in an A319?
It was because they could get there faster on a "TEC route."
IFR flights are subject to congestion management at the ARTCC level, which means they have to wait their turn in line to be allowed into ...
- 27.6k
15
votes
What is the most 'environmentally friendly' way to learn to fly?
By using as much simulator time as possible.
- 21.8k
14
votes
What is more environmentally friendly? An A320 or a car?
It depends on what you mean by "environmentally friendly." Just for an example, let's consider a 1000 mile trip.
An A320 burns about 5 gallons of fuel per seat per hour, and with 150 seats this comes ...
- 71.8k
12
votes
Which engine is more financially economical to operate, a turboprop or gasoline engine?
From a fuel burn perspective, these ballpark numbers can be useful to remember:
Specific Fuel Consumption, Expressed as LBS/HP/HR:
Turboprops - .5 to.7 lbs traditionally, mid .4s to .5 for newer ...
- 126k
11
votes
How much fuel is used for the different phases of the flight of a typical airliner?
From this site by Boeing for the B737-800: fuel used for TO and climb = 2,300 kg.
From this site: fuel burn in cruise for B737-800 is 2,500 kg/hr
From this site: fuel burn at idle of a CFM56 engine = ...
- 61.3k
11
votes
Accepted
What is more environmentally friendly? An A320 or a car?
Overall, the two very different methods of transportation have surprisingly similar amounts of emissions, so close it's tempting to oversimplify things to a statement like "planes are 20% more ...
- 6,725
11
votes
What is the typical fuel consumption of a 737 in MPG?
The following table shows the long range cruise control data for a Boeing 737-800 (source: FCOMv1 Performance Inflight - All Engine PI.31.2):
Let us consider a typical cruise at FL370 with a weight ...
- 54.3k
11
votes
Has there been any attempt to use an underground cable system, a la a cable car, to tow aircraft along taxiways?
Practically this would not work due to the sheer size of the cable you would need. A fully loaded A380 is 1.25 million pounds. A B787 is .5 million pounds and a B737 is about 150,000 pounds. On a busy ...
- 52.9k
11
votes
Accepted
What would be the range of a cargo 777 full of usable fuel up to MTOW?
First, go to the Boeing Airport Planning documents website. This includes a wealth of information about most Boeing commercial aircraft. Choose the document that matches the aircraft you're ...
- 7,319
10
votes
Accepted
Why is my calculated seat-miles per gallon of small aircraft higher than of big aircraft?
All else being equal, your intuition is correct that a larger aircraft will be more efficient (in a gallons per seat-mile measure) than a smaller aircraft. That's why there are big aircraft like 747'...
- 49.8k
9
votes
What is more environmentally friendly? An A320 or a car?
While not specific to an A320, nor a make/model of automobile, these averages may help put your question into perspective. How any of it relates to "environmentally friendly" is purely subjective.
"....
- 91
9
votes
How much does it cost extra to fly with one additional passenger?
I am basing the following calculations on the excellent answer by Peter Kämpf to this question: How much of an improvement would a 1% weight decrease on an airplane be to the industry?.
We can ...
- 54.3k
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