CoolGuy
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What Route Requires The Most Fuel?

Wed Mar 12, 2008 9:04 pm

Posts about the longest flight in terms of distance are one thing, but which flight requires the most fuel? For example, two flights traveling 8000nm may require different amounts of fuel due to the temperature in flight, departure runway altitude, long taxi times, etc.

For example, I think that JFK-JNB was nonstop but the other direction could not be since JNB was at a higher altitude and therefore required more fuel on takeoff. So which routes really test out an aircraft's fuel tanks. Long-haul aircraft, of course.
 
DBCC
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RE: What Route Requires The Most Fuel?

Wed Mar 12, 2008 11:39 pm

Airport altitude has nothing to do with the amount of fuel required to take off. Due to density altitude (temperature and altitude of JNB), the flight may be weight restricted.

Like all Westbound flights, you are flying against the westerly prevailing winds/jet steams from JNB-JFK (like Europe to USA East coast). Even an average head-wind of 100knots, on a 14 hour flight makes 1400NM additional air distance.

A tail wind of 100knots on a 14 hour flight reduces the air distance by 1400NM. So one direction the flight is 2 hours longer than the other.

In theory, JNB-JFK could be done without stopping over, at a push, but on an average day, you would be arriving at JFK with very little reserves. Far too dangerous. Once you are over the mid-atlantic, there are not many places to go to fill up without needing a big detour. Point of no-return is quite early in the flight after the African coast is left.

JNB-CPT-MIA was flown from Cape Town to Miami (or FLL) non-stop, but quite often they had to stop over, unscheduled, in the Bahamas due to head winds. Added 90 minutes to the trip.
 
YULYMX
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RE: What Route Requires The Most Fuel?

Wed Mar 12, 2008 11:50 pm

would guess LAX-SIN going west...
 
CoolGuy
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 1:10 am

JNB-JFK is just one example where it's not only winds but also the altitude. I'm trying to think of ones that stretch the range of an aircraft. That's probably one of them. Probably EWR-SIN too.
 
RobertS975
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 2:20 am

Long north-south flights are not as affected by the jet stream prevailing winds as east-west flights are.
 
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jetmech
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 2:24 am



Quoting CoolGuy (Thread starter):

For SYD-LAX non-stop flights ( 6507 nautical miles ), I was regularly loading fuel to an average ramp figure of around 170 tonnes for a 744.

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
aussie747
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 3:01 am

Don't also forget a 744ER will consume more fuel from MEL to LAX than an A345 from SIN to EWR. But then again it carries quite alot more passengers. So the furthest route does not necc consume the most fuel.
 
OOer
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 3:13 am

how about UA's 744 from ORD - HKG

Whats does that look like?
 
thegeek
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 10:36 am

This question isn't much different from which plane has the biggest fuel tanks. Pre A380, that dubious honour went to the 744ER (ERF is unlikely to have full tanks). LAX->MEL is the sector that they are going to be most full. The A380 will most probably take that title when it starts SIN->LHR flights within the week.
 
roseflyer
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 2:19 pm



Quoting CoolGuy (Thread starter):
So which routes really test out an aircraft's fuel tanks. Long-haul aircraft, of course.

Actually you are almost never going to see long haul aircraft test out the aircraft's fuel tanks. Long haul airplanes pretty much never go out with full tanks.

However you will see it happening on narrowbodies where there isn't as much tank space. When 737 Classics were being operated on long stage length flights such as US East Coast - West Coast flights, then the actual volume of fuel was a concern. Some planes had auxiliary tanks, but others did not. They could be limited by quantity of fuel and not just weight/payload. The A320 and 737NG have larger tanks, but I think those planes are more likely to be limited based on fuel volume.

And finally fuel volume is only truly a concern on business jets. It is a huge concern on commercial planes turned into business jets like the A320/737 Business Jets. It is a huge debate on how many tanks to put in those planes since they will run out of fuel space during their operating lives.
If you have never designed an airplane part before, let the real designers do the work!
 
EXAAUADL
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 2:33 pm



Quoting DBCC (Reply 1):
Airport altitude has nothing to do with the amount of fuel required to take off.

im not so sure, doesnt airspeed have to be higher in JNB to get altitude than in JFK, given equal tempetrures?
 
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DocLightning
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 2:38 pm



Quoting RoseFlyer (Reply 9):

Actually you are almost never going to see long haul aircraft test out the aircraft's fuel tanks. Long haul airplanes pretty much never go out with full tanks.

Why not?
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surfpunk
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 2:39 pm



Quoting RoseFlyer (Reply 9):
However you will see it happening on narrowbodies where there isn't as much tank space.

This is true. While we used to load 400,000+ lbs on 742s from MSP to NRT, they never went out completely full, AFAIK. When NW ran DC9s from MSP to SMF, they would only fly frames fitted with aux tanks, and we would frequently fill those to the gills (each tank to VTO). Although I would also see larger aircraft get filled way high, back when there was a significant enough price difference in fuel between the Midwest and the West Coast to justify the additional burn (50,000+ in a 727, 120,000+ in a DC-10 on routes that normally took 80,000-90,000 lbs).
 
CoolGuy
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 3:28 pm

I guess the phrasing of my question is wrong. A better way to say it is, which long-haul flights have to be filled to the max.
 
YULYMX
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 3:53 pm



Quoting CoolGuy (Reply 13):

Those B772 ER doing JFK/EWR Asia, ORD-BOM/DEL, LAX-TLV on a B772ER
 
jamincan
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 4:08 pm

Don't some flights have to go out with enough fuel to make the return trip due to cost/supply issues at the destination? That might produce a few candidates you wouldn't otherwise consider, though I have no idea which they may be.
 
OldAeroGuy
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 5:23 pm



Quoting DBCC (Reply 1):
In theory, JNB-JFK could be done without stopping over, at a push, but on an average day, you would be arriving at JFK with very little reserves. Far too dangerous.

Not if you're flying a 772LR.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
Qantas744er
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 5:24 pm



Quoting OOer (Reply 7):
how about UA's 744 from ORD - HKG

Whats does that look like?

Will usually go out full with 382,000Lbs of Fuel, plane is at MTOW 95% of the time.

Leo
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DBCC
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 6:21 pm



Quoting EXAAUADL (Reply 10):
Quoting DBCC (Reply 1):
Airport altitude has nothing to do with the amount of fuel required to take off.

im not so sure, doesnt airspeed have to be higher in JNB to get altitude than in JFK, given equal tempetrures?

Airspeed is airspeed, given the same density altitude. A DA is higher in JNB, a slightly higher airspeed will be required, compared to a sea level airport. Also, groundspeed will be higher. But, the additional 10-15 seconds it takes to reach the airspeed on the runway does not make much to the fuel, as at 5'500 feet, you have to climb less to reach FL 310 than from Seal Level.
 
TWA902fly
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 6:47 pm



Quoting Qantas744ER (Reply 17):
Quoting OOer (Reply 7):
how about UA's 744 from ORD - HKG

Whats does that look like?

Will usually go out full with 382,000Lbs of Fuel, plane is at MTOW 95% of the time.

Leo

I just flew this route, and that was the longest takeoff roll i have ever experienced. And ive been on some other 744 flights (ORD-AMS, LAX-PPT, etc), so i assumed it must be pretty full. I believe ORD-HKG is the longest 744 flight in the world, correct me if i am wrong.

'902
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YULYMX
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 6:50 pm



Quoting TWA902fly (Reply 19):

If you are wrong i guess that only JFK-HKG would be longer on a B744 but not sure is still in fonction
 
Superfly
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 6:56 pm

How about the Air Koryo IL-62 flight westbound from Pyongyong, North Korea to Moscow, Russia?
Bring back the Concorde
 
Qantas744er
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 7:01 pm



Quoting YULYMX (Reply 20):

If you are wrong i guess that only JFK-HKG would be longer on a B744 but not sure is still in fonction

No Longer exists Now operated by 3 daily 77W on CX

Quoting TWA902fly (Reply 19):
I just flew this route, and that was the longest takeoff roll i have ever experienced. And ive been on some other 744 flights (ORD-AMS, LAX-PPT, etc), so i assumed it must be pretty full. I believe ORD-HKG is the longest 744 flight in the world, correct me if i am wrong.

Yes it is the longest and TO is pretty long because of the high weights, but even at MTOW on most days a de-rated takeoff will be possible, meaning the engines are given a exterior temperature higher then what it really is and so they will output less power on TO but saving unecessary power and so lower fuel burn and engine wear. This of course resulting in a longer TO. And it is very unusual for a plane to go out at max thrust, because it makes no sence to use it when it is nor required.

Just PM me if you would like some more info!

Leo  Smile
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aruba
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 7:03 pm

Could a A340-500 do JFK - JNB non stop with out worrying to much about fuel? Because that stop over in Dakar is so anoying. And it seems to take more time than it needs too. Because all that needs to be done is fuel. And cleaning of the aircraft.
Will O.
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YULYMX
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 7:09 pm



Quoting Aruba (Reply 23):

Could be done, it is 6925 NM and ewr-sin is 8288 nm and done with A345... going back JNB-JFK probably also... maybe B772LR would be better for no restrictions
 
Flighty
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 7:36 pm

Some other likely candidates include:

AKL-LAX on A332
SFO-NRT on DC-10
Several B757 ETOPS routes like DTW-BRU, EWR-TXL
777 flights such as EWR-HKG
763ER flights... JFK-TLV, others

The EWR-SIN flight is certainly pushing that aircraft's limits for fuel carriage. So was JFK-BKK on Thai A345.

You may also see some 772LRs running out of tank space, since they have the power to carry full loads to the edge of their tank capacity. That is why Boeing offers aux tanks, apparently.
 
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jetmech
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RE: What Route Requires The Most Fuel?

Thu Mar 13, 2008 9:01 pm



Quoting RoseFlyer (Reply 9):
Actually you are almost never going to see long haul aircraft test out the aircraft's fuel tanks. Long haul airplanes pretty much never go out with full tanks.

QF has several non-stop flights a week from SYD-LAX (6507 nm) and MEL-LAX (6883 nm) which would go out with almost full tanks. As I mentioned in reply 5, the average ramp fuel load I used to put on non-ER 744's doing SYD-LAX was around 170 tonnes (374,00lbs). The highest fuel load I remember putting on was about 173 tonnes (380,600lbs).

A non-ER 744 tops out at around 173.4 tonnes (381,480lbs) assuming an S.G. of 0.8kg / lt. IIRC, UA also two daily SYD-LAX flights which I would also imagine come close to topping out.

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
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Starlionblue
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RE: What Route Requires The Most Fuel?

Fri Mar 14, 2008 12:35 am



Quoting Qantas744ER (Reply 22):

Quoting YULYMX (Reply 20):

If you are wrong i guess that only JFK-HKG would be longer on a B744 but not sure is still in fonction

No Longer exists Now operated by 3 daily 77W on CX

CX also uses the 346 on this route.
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zvocio79
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RE: What Route Requires The Most Fuel?

Fri Mar 14, 2008 5:15 pm

how about Santiago, Chile or Buenos Aires, Argentina to Auckland New Zeland????? flying east to west is longer than flying for west to east.....isn't it?
 
WestJetForLife
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RE: What Route Requires The Most Fuel?

Sun Mar 16, 2008 6:37 am

Well, I'm not a commercial pilot, but if I may, I would like to add my contribution to this thread using what (limited) knowledge I can scrounge up.

I think some of the trans-polar (EWR-SIN, ORD/JFK-HKG/NRT) and some of the Kangaroo Routes (LAX/SFO-SYD/MEL, LHR-HKG/SIN/BKK-SYD) would be massive fuel consumers, given their range. I think some of the flights that fly these routes have to fill their tanks anywhere between 90-100% full for these routes. I think also, because of that reason, there are some weight restrictions because of it? (Correct me if I am wrong, fellow A.Net friends.)

Also, I think JFK-PPT (if Air Tahiti Nui still does it) would be a good fuel-consumer too, having to transverse the US and then head south towards Tahiti, all while fighting potential headwinds courtesy of the Jetstream or the Coriolis Effect.

Cheers, and if there are any discrepancies or flaws in my logic, please tell me.

Nik
I need a drink.
 
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Starlionblue
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RE: What Route Requires The Most Fuel?

Sun Mar 16, 2008 12:14 pm



Quoting WestJetForLife (Reply 29):
I think some of the trans-polar (EWR-SIN, ORD/JFK-HKG/NRT) and some of the Kangaroo Routes (LAX/SFO-SYD/MEL, LHR-HKG/SIN/BKK-SYD) would be massive fuel consumers, given their range.

As I understand it, fuel consumption is high in absolute terms, but in terms of pax/miles it's probably not that bad. Only one take-off/climb in all that distance.

BTW JFK-NRT is a good 4 hours less than JFK-HKG.
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