A340-300 performance

[Dash8100]

I'm going to be travelling on an SAS A340-300, and I'm looking forward to it. I read in an other forum that someone rated the A340-300's performance to be rather poor, due to its engines being underpowered. Of course they would be meeting the standard of safe operation, but noting more? Very economic in cruise I guess? Any comments? Thanks.

[Ricky Butcher]

The A343 is cripplingly underpowered, but it was designed to fly very economically at a low-ish Mach No (0.76 I think) and it does it very well. Really annoys the Boeing drivers though!

[Dash8100]

Of course the A340-300 is designed to safely fly and land on three engines. But how would it perform with two engines failed? (Unlikely I know.) Would it be able to maintain some kind of altitude or would it be forced to do a powered glide to the ground? What about other fourengined aircraft? Smaller (Avros) and bigger (747)?

[GlueBall]

Keeping a 4 engined bird in the air on 2 engines has mostly to do with gross weight. If you're light enough it'll keep on trucking at lower altitude. To get lighter you can dump fuel.

A340 Website (http://www.A340.net)

[Flap 5]

For sure it will do better than losing two engines on a 777!

[Volume]

Did the ride on an SAS 340-300 4 weeks ago.
Yes, it is awfully underpowered, takes the whole runway til rotation and doesn´t really climb after. Just had a connection flight on the dash 8 before, what a difference ! might be ten times the climb angle ...
After reducing from take off power (which produces the typical Airbus ´snarring´ engine noise) it is a very quiet cabin, really nice ride.

[goldenrivet]

To give you some sort of idea of the A343 performance, Airbus have pushed all of the performance parameters to every corner of the aircrafts flight envelope in order to make it function as economical as possible. For example, with the standard take-off, climb at 250kt to FL100, 300kt/M0.78 thereafter at a TOW of 250T in ISA the time to FL350 is 33mins covering 211 nm. We operate most of our A340's with a MTOW of 257T.

The cruise performance varies according to the cost index used by the company but nominally with a cost index 50 a M0.80/M0.81 cruise is achieved. The approximate fuel consumption in the cruise is around 6T/hr.

Regarding the two engine out scenario, the gross ceiling at long range speed (more limiting) upto ISA+10 at 250T lies at approx FL140, so probably not as bad as you would first think.

[mutt]

Volume,

Yes, it is awfully underpowered, takes the whole runway til rotation

Has anyone explained the concept of Flex Temperature Takeoffs to you? The fact that the aircraft you rode in used the whole runway may have nothing to do with the actual aircrafts abilities, but it reflects the way which it is operated!

Mutt

[wonderbusdriver]

It´s not underpowered, but not overpowered either - just very economical. (Yes, they would have liked to get the more powerful IAE V2500 engines instead of the CFM56, but they just weren´t ready at the time)

Cruise speed is normally around M 0.82-0.83 which is not as slow as a B757/767. (now go figure out how much "difference" that makes on a ten hour flt compred to a B747 doing M 0.85!)

It doesn´t climb as fast as a twin - like any 4-eng aircraft!
It doesn´t climb as fast a B747/744 - takes 10-15 Min longer to get up to cruise alt, but can usually fly higher than a B747 right from the start.

Fuelflow is way below a B747.

Don´t believe all the BS you read about it.

p.s.: Reduced T/O power (and thus a longer T/O run) when possible, is not unsafe - just plane economical AND safe, since it greatly reduces engine wear especially in the hot section.

[RadarContact]

Just had a connection flight on the dash 8 before, what a difference ! might be ten times the climb angle ...

Probably at ten times the fuel consumption per passenger and mile...

[Rabbit]

As mentioned above, don't believe all the BS you hear on this subject. I have been operating this aircraft for many years now and I can assure you all that most of the comment this fine aircraft gets is rubbish.

We operate the 340 with a cost index of 100 and I can assure you that there are not many aircraft that are quicker. Climb to height does take a while but bear this in mind, the latter part is done at cruise speed, we normally climb higher than the competition and most importantly at a fraction of the fuel burn.

Remember when comparing aircraft you must compare apples with apples and not with oranges. Twins are inherantly overpowered as they must be able to provide sufficient minimum performance should it lose an engine on take off. Losing half your available thrust as against a quarter on a quad is where the differences all begin.

Overall you will find the 340 has all the power it requires to satisfy the necessary performance requirements that all other aircraft are required to achieve. Manufacturers do not provide aircraft with any more thrust than is required to achieve the required performance. To do so is a waste of money and the extra cost may make the type uncompetitive in the market place.

The one thing the aircraft is really famous for is that it is the quietest aircraft in the sky today. Along with the fact that it gives a good ride quality that many other aircraft dream about.

Now I have flown many hours on both Boeing and Airbus types so I can honestly say that both main manufacturers today produce fine aircraft so all the BS about denigrating a particular aircraft performance is a bit silly when ALL aircraft must comply with performance criteria as set down in the various regulations.

Have a nice day