Fuel Flow

Every time I'm trying to make my best decision on ordering a new plane type, I always finding daunting to go over all planes and try to compare fuel efficiency. 

Therefore, I decided to build a table to help me out with those comparisons. I thought I'd share the table with the community. My original table has all the details, but when I paste it over the format gets messed up, so I had to paste only the final calculation. 

For each aircraft I'm using the latest performance data in AE and always choosing the lowest fuel flow engine. 

One thing I've always wondered is why does the 747-8 in AE have less seats than the 747-400... in real life it's kind of the opposite. Anyone knows??

Let me know if you have any questions. 

The CEO of Pacific Airways, a 5 star airline. 

It is not the fuel flow that makes an aircraft great, it is the production rate per capacity.

A380 (>800 seats in 4 weeks) is the best. For smaller planes A321 and Tu204 (>200 seats in 2 weeks) are good too.

Fuel does matter when you are trying to compete in certain markets, particularly the super crowded longhaul ones where only an A380, 788 or something efficient will turn a profit in the later part of the game. 

I would like to know the formulas you used for the calculations, using data from the game as an example.

I would like to know the formulas you used for the calculations, using data from the game as an example.

The fuel flow is lbs/hour, the speed miles/hour and the passengers count in passengers (duh). If you want to have lbs/pax/1000 miles, you have to calculate fuel flow/pax count/speed and multiply by 1000.

Actually, it looks like the data in the game uses kg/hr for fuel flow.

For example, a 747-8 has a max range of 7472 miles with a full load. Divide that by the speed, 570 mph, and you get a number around 13 hours.

For fuel calculations, a 747-8 has a fuel capacity of 63,034 gallons. To convert that to pounds, jet fuel weighs about 62.5% as much as water (which weighs 8lbs/gal), meaning you will multiply the 63,034 gallons by 5 to get 315,170 lbs of fuel. If the fuel flow listed in the game (53,200) were in lbs/hour, then the maximum flight time would be around 6 hours, with a range of about 3,377 miles. Instead, I figure the fuel flow is in kg/hr, which would mean it is 2.2 times what the lbs/hr value is. So we divide the fuel flow (53,200) by 2.2 to get roughly 24,182 lbs/hr (note this is consistent with what pilots have said the fuel flow is, around 12 tons/hr). Now we divide the fuel weight by the actual lbs/hr value (315,170 / 24,182) and you get a number that comes out to about 13 hours, approximately matching the max range.

So the fuel efficiency of a 747-8 is going to be about 70.1 lbs/seat for every 1000 miles. Doing the same calculations with an Airbus A380 yields about 69.46 lbs/seat/1000mi.

Though I have noticed some inconsistency between the fuel range hours (max fuel / fuel flow) and the average speed hours (max range / avg speed) for different aircraft. This shouldn't affect the actual fuel efficiency calculations, though.

Also did some research, turns out the fuel flow data for some aircraft is wrong. For example, in AE the fuel flow for a 787-8 says 33,536 kg/hr when it is closer to 24-25,000 kg/hr.

@Armodeen,

Maybe because the B777 is faster than the A333 and will arrive earlier at the destination than the A333, who has to burn more fuel than the B777

Perseco, Pacific Airways:

I'd be happy to slot this information into a Google Doc spreadsheet (similar to OG's) for ease of browsing. Let me know.

Perseco, Pacific Airways:

 

I'd be happy to slot this information into a Google Doc spreadsheet (similar to OG's) for ease of browsing. Let me know.

I was actually thinking of making a web application for comparison between 2 aircraft. But that's a lot of data to sort through, so if I do that, I will be sticking to Airbus/Boeing/MD/Douglas comparisons to start with.

Actually, it looks like the data in the game uses kg/hr for fuel flow.

 

For example, a 747-8 has a max range of 7472 miles with a full load. Divide that by the speed, 570 mph, and you get a number around 13 hours.

 

For fuel calculations, a 747-8 has a fuel capacity of 63,034 gallons. To convert that to pounds, jet fuel weighs about 62.5% as much as water (which weighs 8lbs/gal), meaning you will multiply the 63,034 gallons by 5 to get 315,170 lbs of fuel. If the fuel flow listed in the game (53,200) were in lbs/hour, then the maximum flight time would be around 6 hours, with a range of about 3,377 miles. Instead, I figure the fuel flow is in kg/hr, which would mean it is 2.2 times what the lbs/hr value is. So we divide the fuel flow (53,200) by 2.2 to get roughly 24,182 lbs/hr (note this is consistent with what pilots have said the fuel flow is, around 12 tons/hr). Now we divide the fuel weight by the actual lbs/hr value (315,170 / 24,182) and you get a number that comes out to about 13 hours, approximately matching the max range.

 

So the fuel efficiency of a 747-8 is going to be about 70.1 lbs/seat for every 1000 miles. Doing the same calculations with an Airbus A380 yields about 69.46 lbs/seat/1000mi.

 

Though I have noticed some inconsistency between the fuel range hours (max fuel / fuel flow) and the average speed hours (max range / avg speed) for different aircraft. This shouldn't affect the actual fuel efficiency calculations, though.

I still believe the fuel is quoted in lbs in the game, although I'm not entirely sure.  

You should note that the "fuel flow" figures used in the game are almost assuming you are running the plane at full throttle, so trying to compare the actual capacity of a 748 and then apply the "game numbers" is going to make it seem as if you plane won't make it anywhere. 

When I compared the numbers in the ICAO website for a GE90-115B in the game vs the real data, the data is dead on assuming a 90% thrust or so. 

Also, I think you may have applied the formula to convert kgs to lbs the other way. remember 1kg = 2.2 lbs, therefore, 53,200 kgs = 117,040 lbs, what you used is the way you would convert from lbs to kg.  which would give you 24,182 lbs

All this to say, it doesn't matter if the data in the game is in kg or lbs, in then end as long as you use the same stick to measure every plane you are going to get an accurate comparison of fuel efficiency among planes.

Perseco, Pacific Airways:

 

I'd be happy to slot this information into a Google Doc spreadsheet (similar to OG's) for ease of browsing. Let me know.

Hey QK, I would love to put it somewhere, but first we need help into getting the fuel efficiency tables out of AE so that we can create the calculation for all the planes. Do you know if we can get that? Otherwise, doing it manually will be cumbersome!

I still believe the fuel is quoted in lbs in the game, although I'm not entirely sure.  

 

You should note that the "fuel flow" figures used in the game are almost assuming you are running the plane at full throttle, so trying to compare the actual capacity of a 748 and then apply the "game numbers" is going to make it seem as if you plane won't make it anywhere. 

 

When I compared the numbers in the ICAO website for a GE90-115B in the game vs the real data, the data is dead on assuming a 90% thrust or so. 

 

Also, I think you may have applied the formula to convert kgs to lbs the other way. remember 1kg = 2.2 lbs, therefore, 53,200 kgs = 117,040 lbs, what you used is the way you would convert from lbs to kg.  which would give you 24,182 lbs

 

All this to say, it doesn't matter if the data in the game is in kg or lbs, in then end as long as you use the same stick to measure every plane you are going to get an accurate comparison of fuel efficiency among planes.

 

 

Hey QK, I would love to put it somewhere, but first we need help into getting the fuel efficiency tables out of AE so that we can create the calculation for all the planes. Do you know if we can get that? Otherwise, doing it manually will be cumbersome!

Ah, you're right. But it certainly isn't in lbs/hr, because then every aircraft would run out of fuel within a relatively short amount of time based on the fuel capacities IRL. I really wish they would put the measurement units (mph, lbs/hr, etc.) in the game... would make things a lot easier and understandable for these types of calculations. But indeed, calculating the efficiency will be the same regardless of the units used for fuel flow.

Ah, you're right. But it certainly isn't in lbs/hr, because then every aircraft would run out of fuel within a relatively short amount of time based on the fuel capacities IRL. I really wish they would put the measurement units (mph, lbs/hr, etc.) in the game... would make things a lot easier and understandable for these types of calculations. But indeed, calculating the efficiency will be the same regardless of the units used for fuel flow.

Did some more calculations (substitute in flight distance for range and you still end up with the same results).

(fuel capacity in lbs / range) * speed = lbs/hr

capacity in lbs / lbs/hr = flight time to given range

As it turns out, the flight time to a given range is exactly equal to the range / speed, as well as the fuel capacity / (lbs/hr per pax * pax).

I calculated the (flight time + turn time) * (2 * weekly round trip flights), and it is equal to the total block time for a route given by AE.

... AE numbers for fuel flow basically don't matter at all, because you can just take the lbs/hr number you get from the above calculations, convert it back to gallons, then calculate the cost by multiplying (gal/hr * round trip flight time) * cost of fuel/gal.

The formula (speed)*(PAX)/Fuel Flow is the best way to decide (at least it always gets it right )

Not neccesarily. Aircraft at cruise only run about with 50% to 70% of maximum power while all AE numbers are for 100% power all the time.
For more information: http://www.airline-e...=6013#entry6013 and the entry before that one.

The easiest way to calculate which aircraft is the most efficient is to simply take the total number of seats you will be putting in the plane, and then dividing the fuel flow by this number.

For example:

A340-300 which I have a 47/197 layout

47+197 = 244

A343 Fuel Flow = ~39,000

39,000/244 = ~160

This means that in the layout I have selected, the A340-300 will be using about 160 units of fuel per hour per passenger.

Of course, this method means that the aircraft need to be in similarly premium or less premium configs to be compared equally, but if you are considering them for the same role they likely would be.