LGW
Topic Author
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Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 7:32 pm

A340's always take off late cos they r under powered for their weight. same with the 346?

LGW
 
CX Flyboy
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 7:59 pm

I believe that the A340-600 will have a lot more power than the current A340s. I saw one take off from HKG for LAX yesterday and it performed more like a 747-400 than an A340, but I have no idea how it was loaded.
 
donder10
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 8:00 pm

The 346 has a much better thrust:weight ratio ,so should be a better climber althoug perhaps less economical?
 
VC-10
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 8:40 pm

A340's always take off late cos they r under powered for their weight - If that was true they would never have got a Type Certificate or a C of A.
 
Joni
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 10:10 pm


LGW,

If 343 is not underpowered, it's built the way it was designed. You might as well say that all 777's are missing 2 engines.

 
N79969
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 10:14 pm

I think LGW meant that the plane had less than ideal power for its weight. Not that it was not safe. The 747-100 was underpowered but received its A/C and T/C. I read once (and I do not recall where) that the earliest 747 models took a very long time to reach cruise altitude. The example they gave was that on a JFK-LAX flight, the original 747 would not reach cruise altitude until the plane was near Chicago. Obviously Boeing fixed the problem quickly.

I think Airbus has heard the same complaint about the 340 and made the necessary changes.
 
racko
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 10:19 pm

The A340 isn't "underpowered", other planes are overpowered. A twin has to be 50% overpowered, a trijet 33% and a quad 25% as they have to be able to take off with a lost engine.
 
Skystar
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 10:42 pm

IIRC, the A346 has a power/weight ratio nearly equivalent to the 773!

Cheers,

Justin
 
DIA
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 11:01 pm

Without getting technical,

We've all heard that the A340 climbs only because the curvature of the Earth, and so on. I've never seen an A340 climbout like a 777, or for that matter, an A320!

I too wonder if it was such a grave concern for Airbus, that they boosted the power substancially for the new A340-500/600 series.

Personally, I don't mind climbing slowly, I love to look out the window at lower altitudes, but I do bet that the airlines mind. Faster climb = fuel/money savings.

Cheers, DIA
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CX Flyboy
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 11:25 pm

DIA,

Twin engines aircraft are always going to be more powerful than 4 engines. They cannot be compared. A twin has to be able to lose an engine (50% of thrust) and still climb away. It has to be very powerful to be able to do this. A 4 engined jet only has to be able to climb with one engine failure (25%), and therefore the other engines don't have to be as powerful.

As for faster climb=more fuel savings....look at the Space Shuttle!!! It burns tonnes and tonnes in seconds!!
 
DIA
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RE: Is The A346 Take-off Late Like The Other 340's?

Fri Apr 12, 2002 11:41 pm

CX:
Comparing the space shuttle is like comparing the Wright Brothers craft to an F-16, two totally different subjects, which is what you were just telling me about comparing 4-engined A/C to 2-engined A/C. Point is well taken. Although, I do dee those 747-400s climbing fast as well.

The Concorde has four engines, but I will not compare it, because it is a different subject, like the space shuttle, so I will assume you are joking.

As with all commercial A/C, the quicker the craft can get to cruise altitude, the more efficient the flight will be in terms of saving on fuel costs. This is why on some short flights, the A/C will climb to altitude, say fl280, fly a few minutes, then begin its descent, rather than staying at fl150 the whole way. Good example: Phoenix to Palm Springs, it's a short hop that basically involves only climbing and descending. Just a few minutes are spent at altitude.
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