Posted on 01/16/2006 9:54:09 AM PST by Righty_McRight
Maybe; Airbus has done it with the A340 once already.
They modified the original A340-200 and -300 versions into the stretched, more powerful, longer-range A340-500 and -600 by replacing the engines, lengthening the fuselage and wings, and enlarging the tail surfaces a bit. As I understand it, the biggest knock on the -300, popular as it's been, is that it's somewhat underpowered and a very poor climber. The -300 uses four 31,500-pound thrust CFM-56C engines (more powerful versions of the ones that power the Boeing 737); the -600 uses four 56,000-pound thrust Rolls Royce Trent 556s. So even though it's 40+ feet longer, it has a LOT more power.
So it's possible they could swap in the GEnx engines from the 787, but more than likely it would require serious airframe modifications. They'd have to make a business decision whether it'd be worth it or not.
BTW, when it enters service, the 777-200LR is going to knock the A340-500 off its pedestal as "longest-ranged airliner in the world."
}:-)4
the problem is that this crate has four engines while the 777 has 2 - it's just ineconomic because it's less aerodynamic and less efficient because you have more moving parts in engines. Plus four engines are more pricey to maitain.
Given the fact that oil gets more and more a short resource (your over next car might already be bought in a situation where oil is 5 times the price of today and nearly to expensive to burn in cars) 4 engined planes are getting even more behind the two engined.
The A 380 and the 787 wil be the planes of the future because they can fulfill the request for low price air transport. The one beeing a bulk carrier the other beeing a versatile long range mid-size aircraft.
Even more amazing is the patriotic circus around these two companies - chirac is not loosing a day to refer to the success of airbus hoping to proof his anti-americanism with the success of a world wide operating company he's visiting every 2 days for a photo shooting - while most people in the US think Boeing is an american company through and through neither subsidized nor technological challanged by anyone.
It's hard to beat the 777 in its class. The GE90 engines are the biggest and most efficient engines, with the highest compression ratios.
The A340 cannot compete in fuel efficiency because it has 4 engines for the same capacity while the 777 has only two.
I was wondering why the A340 was still selling, but I guess it was not. It's strange that airbus went with that design since their ealier successes were due to the twin engine solution of A300 and A310 which with etops allowed them to compete with 3 engined DC10, 727 and 4 engined 707 types.
Technicaly big engines like the GE90 can cost tremendously in weight and drag. The Brits are proponents for numerous small engines, according to Whittle's tradition. I believe the midsize engines of the A340 are either too big to be weight efficient like Whittle's design, and too small to be compression efficient like the GE90. I think the A340 design takes the bad from both world, and not the good. (Note that Russians for a time have been proponents of turboprops and propfans, which, though noisy and inefficient at high speeds, have provided in fact interesting results).
Note that at full capacity, the 747 is still the most fuel efficient airplane per passenger, even more so than the 777! The A380 aims to displace that record held for the past 40 or so years kept by the 747.
The A330 is a twin jet version of the A340 but they apparently cannot slap GE90 engines on it, nor does the elongation of fuselage for larger sitting capacity seem possible.
They need an A340 with twin GE90 type engines, which would be a souped up modified A330, really, a bad copy of the more comfy and wider 777!
When a Boeing designer was asked why the 777 did not have vertical winglets like the airbus, he answered: coz we like our wings horrizontal this way, not that way vertical. Which is true as induced drag is reduced in greater fashion with an increase in span equal to the area of the winglet! (although it may be struturaly more challenging).
Airbust is simply a subsidized job creation program for western europe. No wonder that socialist clown Chirac jerks off thinking about it.
And when you get fat, lazy, and stupid, (by always depending on someone else (EU taxpayers) to provide your R&D money, not your own profits) your bound to get arrogant and make mistakes.
A340 ping.
}:-)4
The A350 is just a attempted cheap knockoff of the 787. They are using an existing body design made of metals like Aluminum that are still 20% heavier than the composite material going on the 787.
The wings will be copied from the 787, and they will just buy the same engines the 787 uses.
So far, sales prove airlines aren't interested. I've heard many have said they efficency numbers Airbust is promising that the A350 will have are completely in the realm of ridiculous, and airlines aren't buying it.
The only ones buying A350's are state-run airlines doing so for "political" reasons, not because its the superior product.
The A340 is a total gashog, just like the A380. End of story.
The only plane airbust recieved impressive orders on this year was the A320, which has a niche. Sales where abysmal for the rest of their their planes.
Boeing made the right call on what airlines where going to want in longhaul travel in the coming years. Airbust didn't and watch where production numbers of planes built are in 2008 compared to Airbust.
It seems like the efficiency of it would be very high, but the downside was low cruise speeds and it was a paradigm shift so support vehicles etc. might have to be altered.
Whatever the Frogs do I hope they dont change the nose gear. After seeing that piece of equipment hold up when the Airbus with the malfunctioning nosestrut landed in LA recently, I'll ride the old bus any day.
Into Roman candles, are we, R.W.?
I've spoken with several commercial pilots, and they like 3-4 propulsion systems in case one engine becomes inoperable. They are not comfortable with twins.
You got that right!
Don't think there's any room for the BWB batmobile in the near future! ;)
I've never heard a commercial pilot make such a statement regarding modern turbofans, for the reason that it's difficult even to imagine a problem that would cause the failure of exactly two, and no more, engines. Back in the post-WWII era of piston-engined commercial aircraft, the ultra-highly stressed, turbocharged radial engines were sufficiently unreliable (and maintenance procedures were less highly developed) that it was not impossible to lose a second engine in a given flight. Those engines also didn't have such excess power that one could climb after losing half the engines. These days, engines are so powerful and reliable that, for example, British Airways continued two recent 10+ hour 747 flights on 3 engines after losing one on takeoff. I question flying with minus one engine much more than I do starting with two in the first place.
BTW, up until, two years ago, I was booking many legs and miles on domestic and some international transatlantic flights. Then again, I am very practical... when your time is up... then...!
I'm not a nervous-nellie, just trying to understand the twins, versus the triples, or the fourples.
It's certainly understandable from the perspective of "if one quits, another one might quit too." But from a safety and engineering perspective, two engines are no less safe these days than four, especially given ETOPS requirements.
The funny thing is that from an engineering perspective, one engine that makes "x" power will always be more efficient than two engines that each make "x/2" power, but a pilot will always want as much redundancy as possible, whether it'll do any good or not. So an engineer would prefer just one really huge engine, while the old joke about the pilot is that when he orders the engineer to "shut down 4", he wants to hear "which four?"
There are plus and minuses with multiengine usage. You need a good pilot to fly with one engine dead, and the more engines, the greater the chances one goes out. A plane gliding down gently with two engines out is much less rough in control. A duchess crashed in my area after one engine went out on take off, all died as "the airplane" lost control and flipped upside down. A single piper did crash too later ahead the runway in a forest, and the guy died there.
Being a glider pilot myself, it's a lot easier to get used to gliding than flying with an engine out in assymetry. Control has become more important than engines. Flybywire fighter jets are useless when the computer glitch occurs, and as a fighter pilot told me, he'd rather see the wings fall off than go into one of those sageburners or pios on take off.
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