# Tag Info

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. ...
• 56.5k

### 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. ...
• 13k

### 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 ...
• 1,543

### 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. ...
• 20k

### 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 ...
• 11.1k

### 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 ...
• 8,138

### 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....
• 7,097
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 ...
• 56.5k

### 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 ...
• 234k

### 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 ...
• 27.6k
Accepted

### Why does using carburetor heat increase fuel consumption?

I can think of two reasons: The efficiency of heat machines depends on the difference between lowest and highest temperature in the cycle, relative to the highest temperature, as formulated first by ...
• 234k

### 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 doesnâ€™t ...
• 16.5k
Accepted

### At what angle to the ground track does wind become favorable to lower fuel consumption?

To solve this problem, let's look at the vector diagram of TAS, GS and Wind Speed (WS): (image source) In this diagram, the angle between the desired course (ground track) and the wind is $\delta$ (...
• 56.5k
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 ...
• 27.7k

### What is the most 'environmentally friendly' way to learn to fly?

By using as much simulator time as possible.
• 22.8k

### 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 ...
• 73.4k

### 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 ...
• 132k

### 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 = ...
• 61.8k
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 ...
• 6,793

### 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 ...
• 56.5k

### 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 ...
• 54k
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### 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 ...
• 13.2k
Accepted

### What is the effect of flying height on helicopter fuel consumption?

The lift equation shows that as air density decreases, as it does with altitude, in order to maintain lift, the speed of the blades must increase or, the coefficient of lift (CL) must increase. Since ...
• 31.3k