Quoting zckls04 (Reply 185): Even if he did, I would posit that he is allowed to change his mind. |
Ok, fair. Chill out Matt.
Quoting zckls04 (Reply 185): where are all these people who still think it's going to be a financial success for Airbus? I haven't seen any in ages. |
I haven't seen any concessions from anyone either. Look this is probably another - chill out Matt. It's just that I like to be clear about what we're discussing, what has or hasn't been conceded. It makes discussions much more clean. I get that most people don't talk this way; it's why nobody likes lawyers. Still would be helpful. I'll just assume that nobody thinks that A380 will be profitable unless someone says otherwise specifically.
Quoting zeke (Reply 186): This statement seems intellectually dishonest, it does not pass the smell test. |
Is the dishonesty by me or by Vinay Biskhara and Bjorn Fehrm at Airwaysnews and Leeham, respectively?
http://airwaysnews.com/blog/2015/01/...ut-a-business-case-exists-for-neo/
http://leehamnews.com/2014/02/03/upd...-a-neo-version-and-whats-involved/
http://leehamnews.com/2014/12/17/a38...ep-analysis-of-its-competitivness/
Quoting zeke (Reply 186): Tim Clarke has previously said the A380 had on per seat basis had between 15-22% lower fuel burn than the 777 |
Please show me the quote. I recall
TC saying A380 and 777 [(total) unit costs are about equal. Because the A380 is indisputably better, per unit, on capital, mx, crew etc., this tells me the fuel picture can't also be better for the A380 in
EK configurations.
Quoting zeke (Reply 186): How anyone can conceivably say with a straight face that a re-engined 777 will have significant advantage re-engined A380 is beyond me. |
Please read the articles. I believe Bjorn and Vinay are quite straight-faced. Note that each of the authors is advocating
****FOR*** the A380neo - let's have no bias talk here.
To me, a bit of very basic and rough arithmetic explains it quite well:
-A380's span-loading of ~4,840lbs/ft is ~47% higher than 777-9's at 3,300lbs/ft.
-Induced drag is proportional to the square of span loading (holding equal cruise altitude, span efficiency, speed, etc.)
-Thus A380 would have ~2.15x as much induced drag as the 779. Ferpe's spreadsheets is in line with this calculation.
-A380's wetted area is ~3,600m2, 777-9's is ~2,700m2. A380 has shorter fuse so say parasitic drag would be ~35% greater than 777-9's.
[this assumes equal
FL's, which is nearly true for the two planes - slightly higher cruise for A380]
Assuming 777-9 drag is ~40% induced and ~60% parasitic, A380's drag delta would be ~67% higher than 777-9.
But A380 has only ~52% more floor area than 779, so it shows more drag per floor area.
...and that's assuming they have equally efficient engines.
Thus the NEO would be worse on fuel than 777-9.
Now of course that's a really rough calculation that favors 777-9 because the weight deltas between the two would be less at average cruise weight than at takeoff. But you get the picture, I don't want to do more work than necessary.
But don't take it from me, read Bjorn and Vinay.
[Edited 2016-02-26 11:14:06]