AvObserver From United States of America, joined Apr 2002, 2478 posts, RR: 9
Reply 5, posted (10 years 4 months 2 days 6 hours ago) and read 4755 times:
I read in Flight International recently that weight reduction measures for the A345/6 have been an ongoing effort at Airbus, with most attention focussed on the wing. I agree it's peculiar these two models weigh that much more than a comparable performance 777; perhaps Airbus should direct its teams working on A380 weight reduction and designing the lighter A330-derived fuselage for the proposed 'A350' to parlay some of their work into these two models, as well. Getting the weight down is crucial for better operating economics; just raising MTOW to meet performance guarantees isn't enough because, all other things being equal, the heavier airplane will burn more fuel.
Antares From Australia, joined Jun 2004, 1402 posts, RR: 38
Reply 7, posted (10 years 4 months 2 days 5 hours ago) and read 4720 times:
Now that the A345 is routinely flying for more than 19 hours with over 170 passengers and up to four tonnes of freight, one wonders what it could do if it was as lightweight on a pax/pax basis as the 777-300ER/-200LR are and will be.
I think the Boeing advantage in lighter weight design will become especially exciting in the e7s.
WIDEBODYPHOTOG From United States of America, joined Jun 1999, 917 posts, RR: 67
Reply 9, posted (10 years 4 months 2 days 2 hours ago) and read 4507 times:
Actually OEW on in service 777-300ER's are more like 387,000lbs(175,500kg) and A346 are 190,000kg. And at that OEW the A346 is heavier than any passenger 747-400 I have seen. It's fuel burn per hour is also closer to a 747-400 than it is to a 777-300ER.
If you want to look at it from a OEW per seat pov, using the factory numbers the 777-300ER is the clear winner there, and disparity is evident when you look at real aircraft that are actually in service.
The A346 is locked in kind of a spiral of sorts,weight increases fuel burn and on and on it goes. The wing structure is very heavy and has a narrow margin of optimum efficiency. It had to be made very strong, stiff and subsequently very heavy because of the high wing loads it has to routinely endure. 777-300ER and A346 have almost identical wing areas, but of course A346 has a much higher MTOW...you do the math.
Also as for 777-200LR. Right now it looks like it could pull off that SIN-EWR-SIN route with payloads of about 105,000lb Eastbound and 90-95,000lb Westbound. That about doubles what I've seen that SIA is getting on that route.
If you know what's really going on then you'll know what to do
Lyzzard From Singapore, joined Nov 2003, 404 posts, RR: 13
Reply 12, posted (10 years 4 months 1 day 21 hours ago) and read 4233 times:
The A345 averages about 8 tons/hr in cruise, although less than a 747-400, it does carry a lot less than the jumbo.
As for the weight issues, I've also been wondering why it's so much heavier than a comparable 777-200. I can only guess the weight is from the extra fuel tanks (there are 3 tanks in each wing, in addition to 2 in the belly section and 1 trim tank in the tail), large crew rest compartment, extra landing gear, extra galley space (in SIA aircraft there are 3 galleys), and the additional heavier engines.