philippelouis1 From United States of America, joined Apr 2011, 2 posts, RR: 0 Reply 1, posted (2 years 3 weeks 5 days 18 hours ago) and read 11942 times:
Can anyone provide me please information about the fuel burn rate of Boeing 777-200LR and 300ER,
I know that they vary under many circumstances and conditions. But what are the data under standard and normal conditions
Maybe for their future high density 773ER at EK, with 442 seats that could be true, but saying that a 772LR which are all configured for 266 seats , is as fuel efficient as the high density 773ER seems to be illogical , to say the least.
Even among their large 773ER fleet there should be large differences knowing that they are going to have no less than 5 different setups ranging from 354 to, 358, 364 , 427 and 442 passengers.
That number is rubbish unless the assumptions associated with them is also listed.
Let me reverse engineer that number to a fuel burn per hour.
Looking at their 2 class 77W, 42J/385Y = 427 pax.
Per 100 km, 427x 2.8 = 1195.6 kg/100 km
Per km = 1195.6/100 = 11.956 / km
So their 2 class 77W would have an average cruise speed of around 880 km/hr
Per hour = 10,521 kg/hr
Looking at their 3 class 77W, 12F/42J/304Y = 358 pax.
Per 100 km, 358x 2.8 = 1002.4 kg/100 km
Per km = 1002.4/100 = 10.024 / km
So their 3 class 77W would have an average cruise speed of around 880 km/hr
Per hour = 8,821 kg/hr
Both of these numbers are clearly wrong. My take on the numbers is that it assumes a certain load factor for the aircraft type, and was derived from RPK and ASK numbers, it does not indicate the fuel burn performance of the aircraft itself.
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Ferpe From France, joined Nov 2010, 1773 posts, RR: 57 Reply 11, posted (2 years 3 weeks 4 days 13 hours ago) and read 11406 times:
I checked what Piano-X would say, it says 5200kg/hr M0,85 cruise burn at FL390 for a 788 where I have adjusted for present weights and loaded to MZFW, should this be OK?
coopdogyo From United States of America, joined Jan 2010, 189 posts, RR: 0 Reply 13, posted (2 years 3 weeks 4 days 7 hours ago) and read 11326 times:
According to a Boeing reference guide I have the 777-200LR burns 3.2 liters per 100 passenger km over and 6,000nm(11,110km) trip and the 777-300ER burns 2.9 liters per 100 passenger km over the same trip.
zeke From Hong Kong, joined Dec 2006, 7726 posts, RR: 73 Reply 14, posted (2 years 3 weeks 4 days 3 hours ago) and read 11248 times:
Quoting coopdogyo (Reply 13): According to a Boeing reference guide I have the 777-200LR burns 3.2 liters per 100 passenger km over and 6,000nm(11,110km) trip and the 777-300ER burns 2.9 liters per 100 passenger km over the same trip.
For the 77L that works out to be 8,476 kg/hr assuming bog standard Boeing 301 pax
For the 77W that works out to be 9,314 kg/hr assuming bog standard Boeing 365 pax
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
arniepie From Belgium, joined Aug 2005, 1265 posts, RR: 1 Reply 15, posted (2 years 3 weeks 4 days 2 hours ago) and read 11230 times:
Quoting zeke (Reply 14): Quoting coopdogyo (Reply 13):
According to a Boeing reference guide I have the 777-200LR burns 3.2 liters per 100 passenger km over and 6,000nm(11,110km) trip and the 777-300ER burns 2.9 liters per 100 passenger km over the same trip.
For the 77L that works out to be 8,476 kg/hr assuming bog standard Boeing 301 pax
For the 77W that works out to be 9,314 kg/hr assuming bog standard Boeing 365 pax
Zeke,
Far for me doubting your numbers but aren't you mixing up kilo's with liters?
eg, the 772LR
-11110 km @ 880 km/h => 12.625 hrs of flight
-3.2L per passenger per 100 km x 301 passengers = 963.2L / 100Km
-963.2 x 111.1 (100km segments) = 107011.52 LITERS of total use or 8,476 LITERS/ hour ,not kilos.(at 100% capacity)
BTW that seems rather optimistic on Boeing's side knowing that fuel is lighter than water at about 0.8KG/L (rough)
Which would translate to 6800kg/hr at full capacity in Boeing standard layout on a 880km/h 111110km 12.625 hr flight .
Sounds rather optimistic.
Now let's redo these numbers for the 266 seat EK 772LR, 11.7% less seats probably means at least 10% less fuel efficiency per passenger, no?
arniepie From Belgium, joined Aug 2005, 1265 posts, RR: 1 Reply 16, posted (2 years 3 weeks 4 days 1 hour ago) and read 11223 times:
I just did the 77W used by EK in its highest density config (427 pax)
8100kg per hour on a 11110km 12.625hr (880kmh) flight means 102262.5kg total use
102262.5kg @ 0.80kg/liter JETA (average specific fuel wheight) makes for 127828.1 Liters totally used.
127828.1Liters for 427 pax in 111.1 segments (100km) would mean 2.6945 Liters per 100km per passenger @ 100% LF.
rather impressive give or take a few percentages when we talk about average fuel consumption.
Offcourse this would not take into consideration that the flight , being so full for such a long distance, would be able to cruise high enough to get to these numbers so early in the flight.
So 2.8L per 100km for the highest density 77W seems feasable if most things work in its favor (TOW not too much cargo, wind direction and windspeed, low CI ,....) at 100% LF
the 772LR at 266pax has no chance of doing the same if my reasoning is anywhere near realistic.
arniepie From Belgium, joined Aug 2005, 1265 posts, RR: 1 Reply 17, posted (2 years 3 weeks 4 days 1 hour ago) and read 11218 times:
for the 77L the numbers go way up
at 100% LF , 266pax for EK
Lets take 7200kg / hour (very optimistic, I realize but lets assume low TOW, no cargo higher initial cruise altitude than on the 77W at low CI .
90900kg used on the 11110Km flight (880kmh) translating to about 113625Liters used.
113625Liters for 111.1 segments (100km) for 266 pax would mean 3.845Liters per 100km per passenger (remember this would be for a 100% LF), not anywhere near the 77W high density configuration.
conclusion for EK (all 100%LF) best possible fuel consumption per passenger per 100km.
sunrisevalley From Canada, joined Jul 2004, 3952 posts, RR: 4 Reply 18, posted (2 years 3 weeks 3 days 13 hours ago) and read 11073 times:
Quoting Stitch (Reply 12): Also from PPRune, Trip Fuel for an EK 777-200LR doing DXB-LAX would be around 121.5t with a ZFW of 209t and a TOW of 342t.
I don't know how you can get a 77L up to a 209t ZFW unless the cargo is considerably above average belly cargo density.
At average density it is volume limited. By my figuring the best that can be achieved is about 42.7t.
Referring to reply 9, the fuel load to meet all diversion, holding requirements etc. for that day was 120t . The burn for the 15hr 55m sector would have been 110.593t. Of this cruise was 100.171t. This was a hypothetical plan and was based on a TOW of about 328t. Now this was a Jespersen plan and was based on a "generic" 77L. I would assume that EK have burn values for each frame so there will be variations.
jetlife2 From United States of America, joined Jul 2006, 214 posts, RR: 25 Reply 19, posted (2 years 3 weeks 3 days 11 hours ago) and read 11054 times:
iwok From Sweden, joined Jan 2005, 1106 posts, RR: 0 Reply 21, posted (4 months 1 week 4 days 9 hours ago) and read 3795 times:
Quoting zeke (Reply 20): Yep I did, my bad, good catch.
Zeke - Any idea how these values change during the flight. I.e. there is a certain fuel usage during, takeoff, clim, initial cruise and cruise just before defending to land. I have got to think that as fuel is consumed that fuel burn drops because gross weight is dropping.
Stitch From United States of America, joined Jul 2005, 26700 posts, RR: 83 Reply 22, posted (4 months 1 week 4 days 8 hours ago) and read 3760 times:
Quoting iwok (Reply 21): Zeke - Any idea how these values change during the flight.
He noted that for a 777-300ER it varied from a low of 6,500kg per hour to a high of 10,500kg per hour across the flight. And for a 747-400, it varies from a low of 9,000kg to a high of 13,000kg per hour.
ferpe From France, joined Nov 2010, 1773 posts, RR: 57 Reply 23, posted (4 months 1 week 3 days 19 hours ago) and read 3568 times:
Quoting iwok (Reply 21): Any idea how these values change during the flight. I.e. there is a certain fuel usage during, takeoff, clim, initial cruise and cruise just before defending to land. I have got to think that as fuel is consumed that fuel burn drops because gross weight is dropping.
What do you want to know and for what frame variants? As I have a cruise drag model which is not to far off I could check a couple of numbers for you but not all these types and the different flight modes.
Zeke can then complement that with real numbers (which normally contain a higher trip fuel contingency then 5% as it also take frame and engine deterioration into account). My model gives you the fuel burns with regulatory reserves, it is within some +-2-3% when I have done things right .
iwok From Sweden, joined Jan 2005, 1106 posts, RR: 0 Reply 24, posted (4 months 1 week 3 days 15 hours ago) and read 3499 times:
Quoting ferpe (Reply 23): What do you want to know and for what frame variants? As I have a cruise drag model which is not to far off I could check a couple of numbers for you but not all these types and the different flight modes.
All thanks very much for your help!
Actually I have to say that I am seeking this info because I am writing proposal for a fuel cell UAV which must operate for a 16-hours mission. In order to estimate how much the power would drop over time I figured I'd use a rough approximation from the 777-LR which also has long mission duration.
That is a very interesting model. Is there anyway I could get a hold of this? I'm actually looking at a small UAV with a catapult launch, hybrid battery for surge, GTOW 30lb and ZFW of 23lb. Cruise is 55mph. That's all I can say about it.
Quoting Stitch (Reply 22): He noted that for a 777-300ER it varied from a low of 6,500kg per hour to a high of 10,500kg per hour across the flight. And for a 747-400, it varies from a low of 9,000kg to a high of 13,000kg per hour.
Both of these give me enough to wave my hands and say as the flight progresses fuel burn drops by 30-40%, depending on a "range of configurations and parameters" and that we will review this in detail once the proposal is awarded
Flighty From United States of America, joined Apr 2007, 7441 posts, RR: 2 Reply 25, posted (4 months 1 week 3 days 15 hours ago) and read 3494 times:
777-200ER typically does 2,300 gallons per hour; DC-10 was up near 3,000 gal per hour. 744, 3,600 gallons. On typical stage lengths. A330-300, about 1,900 gph.
So, I would expect 777-200LR to be around 2,200 gal per hour, and 77W up around 2,900, given the comparisons we know about.
Edit: Given the kg/hr listed above, my numbers may be a little high. They are from the US DOT, as reported by US airlines over many years.
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