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Quoting Viscount724 (Thread starter): I'm curious why it would have to dump fuel when it's already flown over 6,000 nm and been airborne for 13 or 14 hours (scheduled block time DXB-IAH is 16:40)? |
Quoting Viscount724 (Thread starter): Could it really still be over its maximum landing weight after flying so far? |
Quoting Viscount724 (Thread starter): Or would there be any other reason to dump fuel? |
Quoting Viscount724 (Thread starter): Or would there be any other reason to dump fuel? |
Quoting tdscanuck (Reply 1): .given that they were on a pretty long haul their reserves were probably higher than 31,000 lbs |
Quoting Fabo (Reply 3): Quoting tdscanuck (Reply 1): .given that they were on a pretty long haul their reserves were probably higher than 31,000 lbs I'm not sure if reserves are proportional to route length |
Quoting Viscount724 (Thread starter): Coincidentally, about 3 hours earlier a BA 772 en route from SAN to LHR also diverted to YWG due to a medical emegency and dumped fuel. That one I can understand |
Quoting longhauler (Reply 2): On top of the example above, performance might be an issue. If runway conditions at YWG were marginal, a decision to dump fuel to reduce landing weights/speeds/distances could be considered. |
Quoting longhauler (Reply 2): If the aircraft were above MLW, as we all well know, the aircraft can still land, just a maintenance inspection is required before the flight can continue. If the availability of a B777 rated AME were a concern, then being below MLW could speed up the transit. |
Quoting YWG" class="quote" target="_blank">YWG (Reply 5): Monday was a +4c day in YWG, so the runway would have been in pristine condition. RWY 36/18 is 11,000ft long and 31/13 is 8700ft long. Can't really recall the winds, but I don't think they were strong. |
Quoting YWG" class="quote" target="_blank">YWG (Reply 5): It wouldn't surprise me if there was a 777 AME mixed in there, but on the other hand it wouldn't surprise me if there wasn't. Seems like they really only deal with the Airbus family on that line. |
Quoting sunrisevalley (Reply 7): Looked at a flight plan I have for a 77L for a 16hr sector with max fuel load and MTOW. |
Quoting sunrisevalley (Reply 7): Assuming a 155t DOW, 42t payload and 46t of fuel the weight would have been ~243t well over the MLW of 223t. |
Quoting longhauler (Reply 8): I think that is where our calculations may differ. |
Quoting sunrisevalley (Reply 9): |
Quoting longhauler (Reply 10): why would they have planned to MLW at destination, tankering fuel? |
Quoting longhauler (Reply 10): Quite often an airline will "tanker" fuel from one airport to another, when the higher cost at the destination is greater than departure airport + cost of carrying it. I remember this from my A320 days when flying to Cuba. We used to tanker in almost 10t of fuel onto Cuba, so much in fact, we could have held a YYZ alternate for HAV! |
Quoting longhauler (Reply 10): Of course the down side of that ... is that they had to spread it over the canola fields of Canada's prairies! |
Quoting Viscount724 (Thread starter): The aircraft dumped fuel east of Lake Winnipeg and landed without incident or operational impact at 1239z. |
Quoting tdscanuck (Reply 4): They're not, in general. But domestic reserves are lower than international are lower than oceanic...very long flights will drive you into the most conservative reserves because you can get more changes en route than you can with short flights. |
Quoting longhauler (Reply 10): You are right about the fuel burn. I used AC's (very generous) fuel burn for holding fuel of 135K/min, 8100K/hr. |
Quoting longhauler (Reply 10): For this actual flight plan, 103,200 would be burnt, giving an average of 7345K/hr for the whole flight. |
Quoting sunrisevalley (Reply 14): Longhauler, can you disclose what the burn of a 77W would have been with proportionally more weight for the difference in capacity? |