Gigneil From United States of America, joined Nov 2002, 16306 posts, RR: 87 Reply 8, posted (10 years 1 week 2 days 13 hours ago) and read 3117 times:
In the event that Boeing does offer a 772LR with the GE90-115B1, Airbus is of course prepared to offer the Trent 556 on the 345. Rumor had it that EK was going to take theirs that way, but then it seems they didn't.
They are also planning on hanging Trent 558s or 560s off the A340-600HGW. More details TBA.
Zak From Greenland, joined Sep 2003, 1993 posts, RR: 8 Reply 11, posted (10 years 1 week 2 days 11 hours ago) and read 2923 times:
this thread is so stupid, the engine out requirements make twins have more thrust naturally. it would actually be unwise to load up a quad with engines it doesnt need. even the 340 classics are not as underpowered as many people here indicate, but the airbus flex engine mainteance saving strategy shows alot more with their not too great thrust out of the box then with other planes like the a319.
this thread is the usual comparison of things u cant compare. the 777 has to fly and take off reliably on one engine, quads have 3 engines to do the job, so naturally twins are always by far overpowered compared to quads.
and honestly, who cares about thrust on a civil airliner as long as its safe.
they have a few things to accomplish and "thrust that impresses the aviation enthusiast" is not in that book.
safe and economical operation are the things that determine a modern airliner.
thrust to weight ratios are a topic for the military av forum
Dw747400 From United States of America, joined Aug 2001, 1252 posts, RR: 1 Reply 12, posted (10 years 1 week 2 days 11 hours ago) and read 2867 times:
Actually, thrust to weight ratios can have an impact on aircraft design. Thrust is, of course, one of that factors that determines climb performance, as well as initial cruise altitude. This is a contributing factor to why the 777-200 has a higher initial cruise altitude than the A340-300 (not sure about the A340NGs vs. 777NGs, so I'm not going to comment other than say I'd guess the situation is the same).
If your flying over a congested area with lots of slow moving 737s and A320s plodding along at Mach .75-.80 at FL310, its faster and more economical to climb over them and take a direct route. Of course, if an aircraft is designed to operate efficiently at a lower initial altitude and you’re not as worried about other traffic, then it doesn’t make sense to carry as much extra thrust.
Again, thrust is far from the only factor involved in climb and cruise, but to say thrust to weight ratios belong in the military forum overlooks some very important considerations.
I know this is a gross oversimplification of things, but thrust does matter!
Zak From Greenland, joined Sep 2003, 1993 posts, RR: 8 Reply 13, posted (10 years 1 week 2 days 10 hours ago) and read 2790 times:
yes of course thrust matters. but only as a factor to fullfill certain safety limits and to get to whatever is economic.
what exactly is economic for an airline depends on a zillion trillion variables as you also stated and therefore alot of airlines start co using 340 and 777 for example. i am pretty sure we both mean the same thing anyway.
all i wanted to state in the thread is that more thrust doesnt equal the "better" "faster" "whatever" plane, like car ads always imply. and somehow some people also apply that idea to planes, which is really more a thing for the mil av, where speed and such matters more then economical performance.
and since thrust plays a far bigger role in flying performance then in the economical performance of a plane, where its only one of many many factors, i felt i had to chip in that "POWER" isnt what todays airliners are about.
good example is boeings sonic cruiser flop, since more speed didnt mean more overall performance economically (in the opinion of airlines) despite the time savings. etc...