I really like the 747-8I it is a pretty plane and actually also economic. Widebodys are more comfortable and the upper deck is just awesome. For those who wanna fly with the 747: Book a trip with Deutsche Lufthansa or Korean Air. They both use the newest type and probably will keep them flying for a long time. Passengers is what keep them in them flying :)
Boeing quietly pulls plug on the 747, closing era of jumbo jets
211–220 of 223 posts
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#212Another sign of mankind's technological regression when it comes to flight. First we lost the supersonic airliner, now jumbo jets.
Uh, the smaller planes are quite pleasant to fly on. Better cabin pressurization and larger windows. They also allow more long-haul routes. Besides a 777 is not that much smaller than a 747.
Given the damage it causes to the environment, flying should be less comfortable, not more.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#213Earlier quoted context omitted.
Any idea why the A380 is so fuel inefficient? It's a relatively recent design with modern engines etc., no? (I've flown once on an A350. Very nice plane)
There are several reasons. A big one is having four jet engines rather than two. If you had two equivalent aircraft but one a twin jet the other a quad, the twin would have higher efficiency. With each extra engine you pay for it with more drag and reduced overall efficiency. The engines on the A380 aren't actually that modern with the two options being 15-20 year old designs. One of the reasons it was discontinued i…
> A big one is having four jet engines rather than two. If you had two equivalent aircraft but one a twin jet the other a quad, the twin would have higher efficiency.
One can make a good case for turbine engines having better efficiency the larger they are (less losses due to boundary layer friction etc.), so yes, if you have two otherwise equivalent aircraft I'd assume fewer bigger engines would be better. But here we don't have equivalent aircraft, as the A380 is bigger than, well, pretty much any other passenger airliner out there.
The A380 engines produce around 350 kN, which is slightly bigger than, say, the B787 engines. Admittedly the A350 engines are a bit bigger than that, but not by a huge amount. But the data seems to suggest both the 787 and 350 are much more fuel efficient than the A380?
So to make an equivalent comparison, one would take an engine, make a twin engine plane and a quad engine plane with that exact same engine. Naively one could expect the quad version to take twice the number of passengers or cargo, and have roughly the same fuel economy/seat. If not, why not? Which scaling laws are non-linear here?
> The engines on the A380 aren't actually that modern with the two options being 15-20 year old designs. One of the reasons it was discontinued is that no engine manufacturer was willing to make new engines for it, so they weren't able to produce a modern fuel efficient variant.
> And it also makes limited use of composites in its design, so it's heavier than it would be if designed today.
This explanation I can certainly buy. Also that the biggest turbofans are nowadays so large that a twin engine plane is already so big there's a very small market for quads.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#214Earlier quoted context omitted.
> This meant it became profitable (i.e., above the marginal costs of the flights) to fly passenger aircraft purely for the belly-hold freight. That's not the usual definition of "profitable". As you say, they're turning a gross profit (if we treat aircraft leasing costs etc. as fixed, which over a short timeframe they are), but it's not enough to cover their fixed costs, so grandparent is correct that they are not (n…
Is there a single word for "it's more profitable to do this thing, rather than the other thing, or nothing"? I think that's what this counts as. I think this is in the same category of decision as retailers selling old stock at a loss, because that's better than not selling it. A large portion of the modern economy is run by spreadsheets, and crunching the numbers on what the "most-profitable" thing to do often leads…
I think the best terms woud be “marginally profitable”, or “with positive gross unit margin”
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#215Earlier quoted context omitted.
The Concorde was done in by fuel prices, and because it was a small aircraft. I visited one in a museum and it was claustrophobic. Also nobody should be sorry that elites have to sit on long overseas flights just like we do. The A380 was a boondoggle from the beginning, an attempt to outdo Boeing by having TEH BIGGEREST aircraft on the market. Having to rebuild airports to accommodate it wasn't a good idea. The 747 i…
When I worked in aerospace I was told by a Boeing old-timer that he was sure Boeing only made the 747-700X proposal last as long as it did in order to force Airbus into making the A380 mistake, and that none of the Boeing insiders thought a plane that big would ever make real sense to spend money developing. Naturally I have no way to verify this, but it's a fun corporate strategy conspiracy theory.
It's pretty sad how Airbus defines themselves in comparison to Boeing, and Europeans define themselves in comparison to Americans in general. They don't have much identity of their own other than "screw you America! I'm the opposite of whatever you stand for!" It's so small-minded and petty, but unfortunately it's reality.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#216One thing that stands out in TFA is the photo of the cabin mock-up: https://assets.bwbx.io/images/users/iqjWHBFdfxIU/ijEVXdL5LsC... What's the biggest difference? No overhead bins! It looks positively roomy in there. I wonder if the overhead bin model is really the best one -- it feels like a huge bottleneck. Reduces headspace, slows down load in and load out dramatically since it essentially requires that every pass…
Hum, expert in here will correct me if I'm wrong, but, beside the bins, over the years, version after version, I feel that airframes actually slowly shrunk.
The original 747-100's engines were underpowered. That's whey there's extra space for the lounge and more space. As engine technology caught up the aircraft seating increased density.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#217Earlier quoted context omitted.
The A380 also had other issues, in that a freighter version was never developed, and also the dead weight of the plane was a lot heavier than the 747.
[I already answered you once but I thought of another way to think about it that is substantially different than my other comment so thought I'd write another one.] The freight economics issue between the 747F and the A380F is related to the complex soup of fixed costs and variable costs that go into the carrier's choice of platform; in addition to the fuel, the carrier has to amortize the purchase price, and the A38…
That sounds a bit like sunk cost fallacy? The development money is already spent, so the willingness to build the aircraft would seem to be based only on the marginal cost. But with modern financial engineering, who knows.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#218Such a shame. The best flight I ever took was on an A380. The thing was just so big that turbulence didn't seem to affect it. Flying on the jumbo jets was always a trip. With Boeing pulling the plug on the 747, it will be long time before anyone makes a double decker again, if ever.
Once engines are efficient and powerful enough to bolt two on to a double decker and fly across the Pacific, they may come back.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#219Another sign of mankind's technological regression when it comes to flight. First we lost the supersonic airliner, now jumbo jets.
With more efficient engines on smaller planes, we can now fly nonstop transatlantic between city pairs that would never have been available before. Indianapolis to Paris for example. This is a net gain in my opinion over the big hub to hub planes.
Re: Boeing quietly pulls plug on the 747, closing era of jumbo jets
#220Earlier quoted context omitted.
There are several reasons. A big one is having four jet engines rather than two. If you had two equivalent aircraft but one a twin jet the other a quad, the twin would have higher efficiency. With each extra engine you pay for it with more drag and reduced overall efficiency. The engines on the A380 aren't actually that modern with the two options being 15-20 year old designs. One of the reasons it was discontinued i…
> A big one is having four jet engines rather than two. If you had two equivalent aircraft but one a twin jet the other a quad, the twin would have higher efficiency. One can make a good case for turbine engines having better efficiency the larger they are (less losses due to boundary layer friction etc.), so yes, if you have two otherwise equivalent aircraft I'd assume fewer bigger engines would be better. But here…
Some of the problems with the A380 come from the wing design: it has an unusually narrow wing for its weight (out of a desire to remain within the 80m box), along with the shaping of the wing being optimised for a heavier, long A380-900 that never came to market. An unusually large proportion of the drag comes from the wing on the A380.
It's worthwhile looking at where Airbus proposed to improve the A380:
* Densifying the main deck (going to 11-across in economy, still with 18" wide seats). This _alone_ in a typical configuration gives a 9% fuel-per-passenger gain.
* They looked at new engines (derived from the A350, for example) which would provide a 5% fuel burn gain.
* Minor wing modifications (new winglets and slightly reduced wing twist) which would provide a 4% fuel burn gain.
* Longer maintenance intervals (so the aircraft spends more time in the air earning money rather).
Other differences include that it holds much less freight in its belly than a 777 (a much larger proportion of its hold is consumed with passenger luggage), so you lose freight revenue.
It's also worthwhile pointing out that engines are some of the most expensive parts to maintain on an aircraft, so by doubling the number of engines on an aircraft you make a very significant increase on maintenance costs.
At the same time, you have the 777X lengthening the 777 (and increasing capacity) while reducing fuel-burn per seat, a much more versatile aircraft (an A380 will never be profitable on the major of 777X routes!), and more fleet commonality.