Hkg_clk From Hong Kong, joined Jan 2001, 999 posts, RR: 2 Posted (14 years 4 months 2 weeks 1 day 14 hours ago) and read 5238 times:
Many people (both on this forum and elsewhere) have said that the 340 has poor take-off performance. In particular, its take-off performance is worse than the 777, its main competitor. This is certainly true when all engines are fully operational. However, many have therefore criticised the 340 , and have also said that the A340 is unable to take-off at certain airports as the runway is relatively short (see for example the post regarding AF flying 340s to SXM).
However, isn't minimum take-off performance calculated on a 'one-engine-out' scenario? If that is the case, the minimum runway length required for a 777 should be that that is safe for it to take off with 1 engine only (i.e. 50% down on its normal power), whereas that for the 340 is for it to take off with 3 engines (25% down).
If this is correct, then wouldn't the 777 be subject to very stringent runway length restrictions? Taking off with one-engine would, I imagine, require a very long runway. On the other hand, for the 340, it may use up more runway for normal take-offs, but in an engine-out scenario, wouldn't the extra runway length needed be less?
Please correct me if I am wrong! Please note that I'm not saying that four engines is better than two or vice versa, but I'd like to know the practical operational differences when it comes to minimum runway length.
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Artsyman From United States of America, joined Feb 2001, 4748 posts, RR: 32
Reply 3, posted (14 years 4 months 2 weeks 1 day 13 hours ago) and read 4930 times:
The point of the post though is about the actual 343, not the 340 500/600. I have flown the A343 on AF a few times and I must say that I noticed that it felt underpowered "compared to the 777" but underpowered would suggest that it cannot do the job, which it clearly can. It doesnt climb like many others do. I would also say that an A343 with one engine out would obviously be more powerful than a 777 with one engine out, as you would have a 3 engine to 1 engine ratio...
Skystar From Australia, joined Jan 2000, 1363 posts, RR: 2
Reply 4, posted (14 years 4 months 2 weeks 1 day 13 hours ago) and read 4908 times:
Logically a 343 with one engine out (so 3) would be more powerful than a 777 with one engine out (so 1).
However, the notion that when you lose an engine in a twin you have 100% of thrust, and then saying that when you lose an engine in a quad you have 100% thrust isn't quite true - because you're using different standards. ie. the 100%s are different.
FlyDLjets From United States of America, joined Aug 2001, 27 posts, RR: 0
Reply 5, posted (14 years 4 months 2 weeks 1 day 9 hours ago) and read 4849 times:
Granted the A340 does have notably sluggish takeoff performance. But a factor that affects all aircraft is one, density altitude and also for jet aircraft how much the power has to be de-rated to avoid over temping which could lead to an engine fire. If you get a 100 degree day at SXM the engines on the already slightly underpowered 340 would have to be de-rated so much that takeoff from a 7,000 foot runway would be near impossible. This could also feasibly happen to any plane! If you go to A340.net there is a video of a LH 340 departing Phoenix Sky Harbor when it is around 90-100 degrees outside and the plane uses most of the 11,000 foot runway. But agian, we have to think, Air France knows better than most of us. Even if I am a pilot. But you'd have to think that loosing one on a derated takeoff run at SXM would be a hairy experience. Any 340 drivers out there who can give us performance advice?
Cba From United States of America, joined Jul 2000, 4534 posts, RR: 2
Reply 6, posted (14 years 4 months 2 weeks 1 day 8 hours ago) and read 4821 times:
I flew a CO 777 and an AF A340 within 2 weeks of eachother this past Christmas. The A340 climbs like a slug. It rotated off the runway, and hung there for about 5 seconds. The 777 just rocketed up into the sky.
You may be right about DEN and SLC being high altitude hubs, but in all honesty, name me one route (single, non-stop) out of these 2 cities which would require an aircraft the size of and the range of the A340.
Someone mentioned that ATL is "high" altitude, but how does ATL compare to the following cities?
Even DEN (1655m) and SLC (1288m) may be high altitude, but this high altitude argument holds absolutely no water when you look at the operations of the A340 in China.
China Southwest Airlines flies regularly between Chengdu (CTU) and Lhasa (LXA) using the A340. CTU is 507m above sea level. No much, but when you consider that LXA is 3,650m above sea level (more than double the altitude of both DEN and SLC) you can see why this "high altitude" argument has no credibility.
Can anyone comment on why the A340 is able to operate effectively out of Lhasa, but some think it isn't able to operate effectively out of American airports?
Skystar From Australia, joined Jan 2000, 1363 posts, RR: 2
Reply 9, posted (14 years 4 months 2 weeks 1 day 6 hours ago) and read 4772 times:
The max derate temperature for the A340 is 55°C (effectively a 25% derate) - typical for the CFM56.
Generally speaking for large turbofans the max derate is 60°C.
I have to admit, if the runway is only 7000ft, the A340 will have to try very hard to get out. Then again, most large jets will have to. In any case, this will be pushing the limits of its performance.
The A340 is certified to takeoff & land up to 12,000ft.
Airsicknessbag From Germany, joined Aug 2000, 4723 posts, RR: 31
Reply 11, posted (14 years 4 months 2 weeks 1 day 3 hours ago) and read 4733 times:
the 777 is over powered by 100% while the 340 is over powered by only 33% - because the necessary 100% calculation base is indeed the "1 engine out scenario". So quite naturally the 777 is more powerful than the 340 (as is any twin compared to a quad).
A trijet is over powered by 50 % etc.
Dynkrisolo From United States of America, joined Feb 2001, 1896 posts, RR: 6
Reply 14, posted (14 years 4 months 2 weeks 1 day 2 hours ago) and read 4711 times:
The A340 can be comfortably operated out of Lhasa because it is a relatively short flight and the plane is never being closed to fully loaded. It is a misuse of the aircraft. China Southwest was forced to get the three A340s when the Chinese authorities couldn't get the other three major Chinese carriers to have them.
777kicksass From United Kingdom, joined Sep 2000, 668 posts, RR: 0
Reply 16, posted (14 years 4 months 2 weeks 1 day ago) and read 4673 times:
Airsicknessbag - THANKS for getting this straight! I have devoted much of my life to slating the a333s take off performance because it is dreadful. Yes it is within limitations but I think it loses any efficiency it claims to have over the 777 by taking most of the flight to reach cruising altitude!
Yes, the 777 is overpowered incase of an engine failure, moreso than the a330 dueto the engine numbers. I am glad to see Airbus has learnt their lesson and have some decent engines on the 500/600! Maybe a re-engining program for the a330-300? I suppose the smaller a330-200 has no such problems though.
Flight152 From United States of America, joined Nov 2000, 3508 posts, RR: 6
Reply 19, posted (14 years 4 months 2 weeks 21 hours ago) and read 4600 times:
Wouldn't using more flaps for those "hot and high" locations for take-off solve any problem?
No, it wouldn't. By adding an excess amount of flaps, you are also adding more drag, the drag which will make things worse, in this case the takeoff roll even longer. That is why you have to set flap settings to the manufacture settings and not 'play' see what happens if we try this.
Tom_eddf From Germany, joined Apr 2000, 454 posts, RR: 0
Reply 21, posted (14 years 4 months 2 weeks 19 hours ago) and read 4562 times:
I'd say using the A340 on shorthaul flights is of course inefficent, but also not the purpose it was designed for. And on a flight from, let's say FRA to HKG or SIN to SFO, climb performance and initial cruise altitude are not as crucial as on shorter routes.
Shorter routes should be operated by A330's, as far as airlines want to use the 330/340 family. The 333/332 have a much better t/o and climb performance than the quad, but are using engines quite different from the CFMs on the 340, which may lead into maintenance inefficency for airlines which are not using other CFM powered aircraft.
I was onboard of several A340 flights over the atlantic and as a passenger, I always felt safe and comfortable and didn't care about t/o performance. And the A340s cruise performance isn't that bad at all, optimum cruise speed @m.82 is quite above the 767, and I know several airlines operating the A340 at m.83 on some routes. Not to mention the A340s superior range capabilities.
However, I wondered why airbus did not offer the A340-300 with PW2000 engines...
Tom_eddf From Germany, joined Apr 2000, 454 posts, RR: 0
Reply 24, posted (14 years 4 months 2 weeks 15 hours ago) and read 4498 times:
Don't want to start an a vs. b war, but last time i checked the specs, the A340-213X (known as the A340-8000) had a range of 8000nm, more than any commercial airliner available today.
Older A340-200s (like the -311) are capable to fly 7450nm non stop, while the A340-313X fully loaded with passengers and baggage flies 7300nm.
The maximum range for the 777-200ER is, if i'm not wrong, 7150nm. Very close, but the 340 flies a bit farther.
Beside that, saying "superior" does not mean to compare the A340 to the 777 or A vs. B anytime, I even did not mention the 777 in my posting. By the way, there are other long range birds in the sky, like the 762/763ER, A332/3, some DC-10s, MD-11s and numerous 747s. And the A340 (as well as the 772ER, indeed) offer more range than most of them.
: From ATC point of view this is really simple: 2 engine jets climb much better then 4 engine.
: A Lufthansa A340 captain once told me, that he can directly climb to FL390 or similar for example. A B747 for some erason has to do a level off to bur
: Note here: The frequently quoted engine-out scenario actually works like this: Any passenger plane has to be capable of safe takeoff if an engine fail
: When Sabena used to Fly A340's out of CVG they would take up most of CVG's 10,000 foot long runway 18L. It made me kind of Nervous! (CVG is about 950
: 340s regular do reduced-power takeoffs which are more economical and reduce engine wear and tear.
: The one-engine out scenario is probably the driving factor for the relatively higher take-off power of a twin vs. the A340. However, there are probabl
: Something that may have been mentioned, but I missed is that ALL airplanes have three take off airspeeds noted (sometimes more). I'll use an example b
32 El Al 001
: LH404, Thats right, a year ago I took a night flight to JFK from TLV, the a/c was 744 (LY) and we were 100% full with maximum payload. Until Vienna we
: Hopefully with this TECH56 project GE/SNECMA is working on will boost the thrust of the CFM56-5C engine to close to 40,000lbs, which will help the A34
: Tom_eddf: Find me an airline that has ordered the A340-8000. Airbus has not sold a single one of them to an airline customer. Then obviously its "supe
: I was on a Lufthansa Airlines A340-300 twice in 2001. I have to tell you, the A340 has such a GREAT climb, it is truely spectacular! It climbed very f
: Climb performance is very different than takeoff performance. Other limitations control climb, which do not limit takeoff. Cameron
: I have to say this, but as a passenger, I don't care what kind of takeoff/climb performance the A340-300 has, to me and to many pilots I've met, it is
: Hello TK, Well said!! I agree with You. I am affraid that most of the people criticising the A340 take-off performance, do not realize that most of th
: All I can say is that the takeoff roll of the A340-300 reminds of a 747-400 takeoff roll fully loaded--it takes a long roll down the runway even in th
: My question is why NOT to use the whole runway to take off? If a B777 can take off, let's say with 20-25% less runway length than an A340, why not to
: Sigh! To say the A343E is a fantastic plane is like to say the B764ER is a fantastic plane. Well, airlines aren't buying too many of them.
: Hi Dynkrisolo, more than 300 costumers had ordered A340, and about 250 is A343X(E) So the plane is sucessful in its class But You can not say that abo
: Although I admit that saying the A340 is as slow-selling as the 767-400ER is a bit drastic, when compared to the respective competition, the comparisi
: AS a passenger, i don't care about how long it takes to FL350 as long as we got there, last year, i have a chat with a SIA 744 Captain in London, he s
: Without looking at any numbers or any other facts, relying on only my expierences while plane spotting, the A340 does rotate and climb "like a slug" a
: Andrej: Remember the number that Hamlet69 posted for the A340 includes three years of sales before the B777 was launched. In the first few years of ma
: Dynkrisolo Yes but unfortunately, Hamlet69 hasn't speak of the A330-300 that is indeed a competitor of the 777. So you have to add the +115 A330-300 b
: The way I see it.... All engines work during takeoff - you survive in the 777 and 340 One engine fails at a critical time during takeoff - you survive
: Johannesburg is a long way above sea level and is also very hot which results in draining the engines' power. It often takes Virgin 70 seconds to take
: OO-AOG, I didn't use A330-300 numbers because we were comparing direct competitors, i.e., 300 seat long-range aircraft. If we look at medium-haul airc
: I think the A340 is a wonderfull plane for the passengers. It has a smoth climbing and it never sounds as intent as a 777 or 330. Only the 747 comes c
: Hamlet69: >> Although I admit that saying the A340 is as slow-selling as the 767-400ER is a bit drastic, when compared to the respective competition,
: I suspect the 343 and 772er share very close in-air operating costs.But its probabarly the cheaper maintenace of the 772 that makes it more popular.If
: Magyar, This forum is ripe with supporters of both Airbus and Boeing claiming how one aircraft or another is a 'failure' based solely on either its nu
: The A340s t/o and climb performance is the price it has to pay for such a long range, they could have given it more powerful engines-but why carry the
: Hamlet69 wrote: >> To be perfectly honest, so is the A340-300. The future sales prospects are far from promising. There remains very few airlines that
: Magyar, Oopps! I left out an entire line of what I was going to write. Sorry! Here is the complete sentence: "There remains very few airlines that rem
: Prior to the B777 launch, Airbus had received orders for more than 120 A333s. So if you look at the post B777 launch orders, the baseline B772 and the
: Hi everyone, AF used to operate A340-200's to MEX for about 4-5 years. Now, as some of you probably know, MEX is located at about 2,300 meters (7000+
: Dynkrisolo wrote: >> B777, it means this sector is pretty robust. If Airbus has problem attracting customers to buy the A343, it means the product has
: Magyar: If there is a better plane than the A343, then the A343 is deficient relative to the competition, period. And who's arguing that the A330/340
: Hi all, I haven't had the opportunity to fly on A340 yet. Virgin, Swissair, Iberia all fly 340's in and out of here (Johannesburg). The altitude is ov
: I'm pretty sure that Flex t/o power setting was in use when I noticed our takeoff roll of 1 min. 24 sec. @ FRA RWY 18 on our way to DFW. Rollin' and r
: I honestly don't think that AF will phase out their A340s in preference of the 777 as somebody wrote above. The reason for AF to chose the 777 is that
: FLEX, DERATE or STD T/O power settings are used in all aircraft as opposed to MAX T/O THRUST whenever conditions permit. This is not an Airbus thing.
: Tom_eddf wrote: [quote] One of the reason for the higher numbers of 777s sold is the fact that leading US carriers prefer Boeings on the long range ma
: I you look at A340/330 customer in Asia. Nearly all of them also operates 777. CX, TG, AF. Even small carriers such as BR will be operating 777 along
: Dynkrisolo wrote: "Nonsense. If your theory is correct, then the B737 should have at least 70% of the market instead of sharing the market fairly even
: A340 with only 3 engines for better performance than B777, I dont think so... A340 could been a trijet instead..... !!!! baec777
: Tom_eddf: Gimme a break. Why is your "theory" so conveniently applies to long-range aircraft only? Your theory is absolute nonsense. You suggested tha
: My personal believe is that this is a pure marketing game. Boeing's strategy is to tout that their "2 engined birds are cheaper to operate yet as safe
: Flitepathsa, Virgin fly out of Cape Town to LHR in the early morning with a 343.
: Dynkrisolo you should not have bring this up: >> Nonsense. If your theory is correct, then the B737 should have at least 70% of the market instead of
: Magyar: The US domestic market is the largest market in the world. It has the greatest demand for narrowbody aircraft. Therefore, it is not a big surp
: Spk: Airbus has not proven it is safer to have more engines on an aircraft. It is a fact that there are more delays and cancellations, more turnbacks,
: Their is more to the 2 (777) versus 4 engine (A340-300)debate than "engine failure". When an aircraft encounters severe windshear, I doubt anyone on b
: BTW, why would airlines care about climb performance? A340 has a good range, cabin comfort and low cost. Aren't that the main points they should care?