CoolGuy From United States of America, joined Jan 2005, 414 posts, RR: 0 Posted (7 years 4 months 3 weeks 3 days 5 hours ago) and read 6172 times:
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 From Switzerland, joined Nov 2007, 65 posts, RR: 0
Reply 1, posted (7 years 4 months 3 weeks 3 days 3 hours ago) and read 6032 times:
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.
Aussie747 From Australia, joined Aug 2003, 1167 posts, RR: 0
Reply 6, posted (7 years 4 months 3 weeks 3 days ago) and read 5672 times:
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.
Thegeek From Australia, joined Nov 2007, 2638 posts, RR: 0
Reply 8, posted (7 years 4 months 3 weeks 2 days 16 hours ago) and read 5442 times:
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 From United States of America, joined Feb 2004, 10415 posts, RR: 52
Reply 9, posted (7 years 4 months 3 weeks 2 days 12 hours ago) and read 5220 times:
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.
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Surfpunk From United States of America, joined Sep 2007, 253 posts, RR: 0
Reply 12, posted (7 years 4 months 3 weeks 2 days 12 hours ago) and read 5167 times:
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).
Jamincan From Canada, joined Aug 2006, 784 posts, RR: 0
Reply 15, posted (7 years 4 months 3 weeks 2 days 10 hours ago) and read 5012 times:
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.
DBCC From Switzerland, joined Nov 2007, 65 posts, RR: 0
Reply 18, posted (7 years 4 months 3 weeks 2 days 8 hours ago) and read 4117 times:
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.
Will usually go out full with 382,000Lbs of Fuel, plane is at MTOW 95% of the time.
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.
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Qantas744ER From United States of America, joined Jun 2005, 1336 posts, RR: 3
Reply 22, posted (7 years 4 months 3 weeks 2 days 8 hours ago) and read 3735 times:
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.
Aruba From United States of America, joined Aug 2006, 128 posts, RR: 0
Reply 23, posted (7 years 4 months 3 weeks 2 days 7 hours ago) and read 3696 times:
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.
B738,B752,A310,A319,A321,A343,A346,Dash8,EMB170_JFK,BDL,MBJ,SJU,AUA,DKR,JNB,CPT,HDS,IAD...But South Africa is the best!