Keesje From , joined Dec 1969, posts, RR: Posted (3 years 9 months 6 days 3 hours ago) and read 43496 times:
In the Global Market Forecast 2009-2028 http://www.airbus.com/en/gmf2009/ shows some Airbus A30X concepts on page 82. Some are more recent, some older. They show various configurations.
A "conventional" airframe / longer sleeker wing with high pass turbofans on top of the aft body. ACARE configurations that surfaced yrs ago :
Forward swept wings, canards and counter rotating open rotors on top.
A more unconventional configuration, wider body & engines lower.
B777LRF From Luxembourg, joined Nov 2008, 1015 posts, RR: 3 Reply 2, posted (3 years 9 months 6 days 2 hours ago) and read 43356 times:
First study has me questioning the interference between engines and horisontal stabiliser, whilst the second one looks like it could suffer from negative consequences of propwash over same. It also raises the issue of having an inherently unstable aircraft performing commercial passenger service, in reference to the forward swept wings.
Third study, if wide enough, might incorporate lifting-body elements, and that would be interesting. Not sure about the engine placement though. And the windows will of course be replaced with a bog standard 6-piece kit.
In all three cases - nothing really new or particulary inventive. Neither are they, I suppose, looking anything like the next generation short- medium-haul Airbus.
From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
Keesje From , joined Dec 1969, posts, RR: Reply 4, posted (3 years 9 months 6 days 2 hours ago) and read 43258 times:
Quoting Stitch (Reply 3): Welp, only fifteen years to see which way Airbus goes based on JL's comments today.
I would not put to much weight in that. In 2007 he said 2020, last year he said 2015, earlier this yr 2020 and now 2024. Maybe next yr when oil hits $100 a barrel and Bombardier sold 500 CSeries he says 2017.
Maybe he's simply protecting the A320 backlog / sales position and the Airbus bank account. Developping the A380, A400M and A350XWB within 10 yrs doesn't have the board room cheer out when a new mega project $urface$. If it's neccessary it will be done but the later the better.
B777LRF From Luxembourg, joined Nov 2008, 1015 posts, RR: 3 Reply 6, posted (3 years 9 months 6 days 1 hour ago) and read 43149 times:
The HansaJet wasn't an unstable design. Presumeably, a 21st century jet would incorporate forward swept wing technology because it promises reduce drag, but only if the design is unstable. Probably the reason they put canards on the thing.
From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
Tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 8, posted (3 years 9 months 5 days 22 hours ago) and read 42704 times:
Quoting Keesje (Thread starter):
Forward swept wings, canards and counter rotating open rotors on top.
That's going to be one honker of a nose gear. The wing is so far back (expected for an open rotor) that there's no way to conventionally mount the main gear and still keep most of the load on the main gear. A significantly load-bearing & braking nose-gear would be an interesting design concept.
Quoting B777LRF (Reply 2): It also raises the issue of having an inherently unstable aircraft performing commercial passenger service, in reference to the forward swept wings.
I'm not positive about this, but I can't see any particular reason a forward sweep is inherently unstable (although it certainly can be).
Quoting Breiz (Reply 7): You are right, but this is already known territory. Relaxed stability is in use on fly-by-wire planes.
Relaxed stability is not instability...there are no unstable commercial jets in service at the moment that I'm aware of.
Keesje From , joined Dec 1969, posts, RR: Reply 9, posted (3 years 9 months 5 days 17 hours ago) and read 42295 times:
Quoting Stitch (Reply 3): Quoting Keesje (Thread starter):
The U tail seems popular anyway.
More like mandated by the engine placement.
Well various options are possible. The first one has apparently been studied a lot over the years. Look for ACARE (a european research program) and it pops up.
A few yrs ago I suggested Boeing and Embraer might partner to cover the lower segment of the narrowbody market with a joint development with such similar configuration, 5 abreast up to 160 seats: http://i191.photobucket.com/albums/z...Boeing_Embraer_Y1_narrow_bod-1.jpg
Graphics by Henry Lam (www.kaktusdigital.com>)
Scbriml From United Kingdom, joined Jul 2003, 11443 posts, RR: 50 Reply 10, posted (3 years 9 months 5 days 17 hours ago) and read 42210 times:
Quoting Keesje (Reply 4): Maybe next yr when oil hits $100 a barrel and Bombardier sold 500 CSeries he says 2017.
The first of those is a possibility, the second is far-fetched in the extreme IMHO.
I know you're a fan of the C-Series, but it's not exactly setting the World on fire is it? I don't think either Airbus or Boeing is that concerned given the low proportion of sales they have in the sub-150 seat market.
DocLightning From United States of America, joined Nov 2005, 16936 posts, RR: 57 Reply 12, posted (3 years 9 months 5 days 14 hours ago) and read 40920 times:
Quoting Tropical (Reply 1): Sexy! Especially the last one Smile
DocLightning From United States of America, joined Nov 2005, 16936 posts, RR: 57 Reply 14, posted (3 years 9 months 5 days 12 hours ago) and read 39028 times:
Quoting FWI747 (Reply 13):
Did you say Sonic cruiser ... Smile
They do look awfully similar, do they not?
If getting a conventionally-shaped, but all-electric/CFRP plane into the air was a 3 year delay, imagine what happens when they completely change the geometry of an airliner!
Stitch From United States of America, joined Jul 2005, 26956 posts, RR: 83 Reply 15, posted (3 years 9 months 5 days 12 hours ago) and read 38957 times:
Having worked on the Sonic Cruiser program, I don't see any great similarity. *shrug*
DocLightning From United States of America, joined Nov 2005, 16936 posts, RR: 57 Reply 17, posted (3 years 9 months 5 days 11 hours ago) and read 38475 times:
Quoting Babybus (Reply 16):
A VC10 or a Tristar was vastly more comfortable than some of the airframes we are crammed into nowadays.
Flying was still new back then and not everyone got to do it. Also, comfort depends on the carrier, not the airframe.
Manfredj From United States of America, joined Mar 2007, 1132 posts, RR: 0 Reply 19, posted (3 years 9 months 5 days 10 hours ago) and read 37713 times:
Why were the 727 and 747 such fast aircraft, yet pretty fuel efficient for their time? Couldn't you take those same designs and incorporate more fuel thrifty engines?
Sorry if I sound stupid, I'm not well educated on the design of aircraft, but it makes sense from a layman's point of view. I do recall something special about the design of the 727's wing which made it stand out from the norm.
EA772LR From United States of America, joined Mar 2007, 2836 posts, RR: 10 Reply 20, posted (3 years 9 months 5 days 10 hours ago) and read 37615 times:
Quoting Babybus (Reply 16): A VC10 or a Tristar was vastly more comfortable than some of the airframes we are crammed into nowadays.
True. I remember flying DL's L1011s a lot as a kid when we lived in ATL. But those older designs were phased out for what we have now, because for the time being, what we have currently with aircraft designs are the most efficient ways to make planes at current tech levels. Although the tri-jets and 150 seat quads were cool, they are far less efficient than what is currently filling that role. But we can dream right...
We often judge others by their actions, but ourselves by our intentions.
Keta From Germany, joined Mar 2005, 444 posts, RR: 0 Reply 24, posted (3 years 9 months 5 days 9 hours ago) and read 36567 times:
Quoting Manfredj (Reply 19): Why were the 727 and 747 such fast aircraft, yet pretty fuel efficient for their time? Couldn't you take those same designs and incorporate more fuel thrifty engines?
Rest assured, that modern wings are far more efficient than those of the 727.
26 Manfredj: Efficient yes, but how about performance? Compared to a modern A320, the 727 enjoys a shorter takeoff length, higher max speed, higher service ceilin
27 Shany: I would assume, that the short take off capability of the B727 are more attributed to the flap system than to the wing itself. Shany
28 Rampart: I'm not the only one thinking Sonic Cruiser, no offense to Stitch. Long established aerodynamic benefits. http://www.centennialofflight.gov/es..._Tec
29 Birdbrainz: Looking at the first two, I'd really wonder about the drawbacks of placing the engines so high up. Namely, the pitch-down moment when more power is ap
30 Stitch: For a prop-fan, you arguably have little choice but to put them up there for noise and damage-reduction reasons. A large horizontal stabilizer with t
31 Keta: I'd love to see some actual figures of aerodynamic improvement of forward-swept wings over back-swept wings (not being ironic, I really want to see t
32 Osetka: They all look ridiculous. Not nice at all........
33 Stitch: NASA has done studies (the X-29 program) so the data should be publicly available.
34 Q120: I think they are some of the nicest designs out there, a little radical but I really like it. I hope something like this gets constructed in the near
35 Birdbrainz: Yes. I understand the motivation for putting them up there, but it comes at a high cost: unwanted pitch down as power is increased, as well as mainte
36 Stitch: This is why I am rather skeptical that Prop-Fans will be a popular form of propulsion for airliners, even "smaller" ones (100+ seats).
37 Viscount724: Not sure how many 727s you have flown on, but at heavy weights on sectors of 1,500 miles or more, the 727-200 in particular did not have a short take
38 Manfredj: Yes, I've watched many 727's with that rather long takeoff as a child. I didn't know as a child it was probably due to heavy fuel load. I've flown my
39 Keta: Yes, that's the mentality behind great inventions I however have the feeling that prop-fans have a chance...
40 Keesje: The wings & propulsion changed (NACRE '08).. http://www.flightglobal.com/articles...ugh-2008-reshaping-the-future.html Regarding open rotor concepts,
41 Tdscanuck: Don't blame the manufacturers...they build what the airlines want to buy. If the airlines wanted that, that's what the OEM's would build. Yes, but th
42 Birdbrainz: Depends on which one: the 727-200 was a dog, although the 727-100 and -222A wasn't bad. I'll agree, though, it wasn't a rocket. My dad thought there
43 FrmrCAPCADET: It probably is always more fuel efficient to use the whole runway to take off. Hot dogging always cost money.
44 Stitch: I'd say they did do it for the 727 with the 757 which has a similar cruising speed of around Mach .80.
45 Hloutweg: I thought exactly the same. It seems to be an aerodynamicly ideal wing for rear mounted engined aircraft.
46 Keesje: I think this (great) artist impression VIDEO by Henry Lam (kaktus digital) for the RAS comes pretty close to concept 2. Video : http://www.youtube.com
47 Stitch: Pretty, as are most of his designs. Drop the undercarriage fairings, though.
48 R2rho: We should expect something like number 1, or the NLR concept, or the RAS concept. They have the best trade-off between new technology and too radical
49 EBJ1248650: I thought the same thing. Even the nose has a similarity to the 727.
50 Parapente: Having spent my whole life looking at planes that are carbon (no punn) copies of each other it will be exciting to see where they come out on this. I
51 David L: I've spent a similar number of years drooling over the next generation design concepts... which always seem to remain as the "next" generation and ne
52 Rampart: Literally. The wheel pants have to come off so that the gear can retract into the fuselage. Fairings parachute down to be recovered and reused for th
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