Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
Armadillo1
Posts: 647
Joined: Thu Apr 20, 2017 5:14 pm

Re: 2 vs 4 engines

Tue Jan 05, 2021 9:34 am

looking at all this threads looks like the onl advantage of twin is dispatch availability
 
User avatar
Starlionblue
Posts: 20700
Joined: Fri Feb 27, 2004 9:54 pm

Re: 2 vs 4 engines

Tue Jan 05, 2021 9:40 am

Armadillo1 wrote:
looking at all this threads looks like the onl advantage of twin is dispatch availability


Not even that. Since there are more engines, there are more bits than can break. Twins win again.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
GalaxyFlyer
Posts: 7821
Joined: Fri Jan 01, 2016 4:44 am

Re: 2 vs 4 engines

Tue Jan 05, 2021 3:37 pm

Do you think Airbus is stupid in not considering an A340NEO? I’m pretty sure they’re not, but you never know,
 
Carmitage
Topic Author
Posts: 47
Joined: Tue Jan 17, 2017 1:24 pm

Re: 2 vs 4 engines

Wed Jan 06, 2021 1:12 pm

PM wrote:
Sokes wrote:
Has there ever been a case where four engines were chosen when two engines could have done the job?

BAe146? I believe there was no suitable engine if they wanted two so they went with four.


The joke at the time with the reportedly poor reliability was:
"Why does the BAe146 have 4 engines?"

"Because they couldn't get 5 on"
 
Carmitage
Topic Author
Posts: 47
Joined: Tue Jan 17, 2017 1:24 pm

Re: 2 vs 4 engines

Wed Jan 06, 2021 1:33 pm

SEPilot wrote:
This hasn’t been mentioned so far, but years ago I did a study of all crashes that I could find that were caused by engine issues (including engines falling off). What I found was that the same number of engine caused crashes had occurred in twins as in planes with more than two engines. I found this very interesting, as there are far more twins flying than planes with more engines. It indicates, contrary to popular opinion, that twins are actually safer than tris or quads. On closer examination, it actually makes sense. What are the engine issues likely to cause a crash? Two come to mind and are supported by history; the first is an uncontained engine failure doing structural damage. This is actually more likely the more engines you have. The second is an engine falling off doing structural damage and/or striking another one and causing it to fall off. Again, the first is more likely the more engines you have, and the second can only happen on a quad. Note that I can not find a single example of two unrelated engine failures on a single flight for jet engines, not even for B-52s. But since military records are less available I would not say there has never been one; I just couldn’t find it.


This is why the Harrier only had one engine - the most critical part of the flight envelope was hover and there was no way they could put two (or more) engines on that would give stability in hover with an engine out. Therefore it was safer to have one engine than multiple engines as the probability of a fail-unsafe is lower.
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Wed Jan 06, 2021 7:47 pm

zeke wrote:
VierBe wrote:
Somewhere else I read that a slat is different and some smaller tweaks but essentially it's the same wing that was also supposed to hold the Superfan, which is basically the PW1133g. Sorry I don't see, why there needes to be a new wing.

Needs to be something else. Oh guys, that would be a superb looking airliner. :)


That is correct, the wings are essentially the same, the deflections on flaps etc are slightly different between the the A330/340.

As for the wing itself, it was sized around the CFM56 engines, so it is designed not only to be able to takeoff with the fuel onboard for 12-14 hours, that increases the TOW, which the wing needs to be strong enough to hold, also the weight of those engines.

Countering the wing lift if the weight of the fuel and the weight of the engines. Changing to the new A320 engine would reduce fuel burn back closer to around 1-1.5 tonne per engine per hour, that means the fuel mass that is in the wing will be a lot lower as well as the reduced weight of the engine. The wing then would be significantly oversized resulting in the empty weight being much higher than it needs to be. It would still not be as capable as the A350-900 in range or payload.

Doesn't this argument also apply to the 339 with the wings being oversized for a lower fuel need? I'd imagine in the case of an A340neo, if you didn't need as much fuel, you'd leave the center tank empty and fill in more payload. Given the same structure as the 343, your range at MZFW would go out to ~6300ish nm, which is a bit much. That would give you more payload/range than a 359, but more of it in weight versus volume.
Image
 
User avatar
zeke
Posts: 16130
Joined: Thu Dec 14, 2006 1:42 pm

Re: 2 vs 4 engines

Wed Jan 06, 2021 9:11 pm

LH707330 wrote:
Doesn't this argument also apply to the 339 with the wings being oversized for a lower fuel need? I'd imagine in the case of an A340neo, if you didn't need as much fuel, you'd leave the center tank empty and fill in more payload. Given the same structure as the 343, your range at MZFW would go out to ~6300ish nm, which is a bit much. That would give you more payload/range than a 359, but more of it in weight versus volume.


The only people that would MZFW out that far would be in a freighter configuration. The A339 now has the capability the A343 had, it is oversized for the original role the A333 had at 4000 nm, if they wanted to optimise for 4000 nm it would involve a smaller wing, and smaller engine however it would not be as effective at longer ranges,
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 6:14 am

zeke wrote:
LH707330 wrote:
Doesn't this argument also apply to the 339 with the wings being oversized for a lower fuel need? I'd imagine in the case of an A340neo, if you didn't need as much fuel, you'd leave the center tank empty and fill in more payload. Given the same structure as the 343, your range at MZFW would go out to ~6300ish nm, which is a bit much. That would give you more payload/range than a 359, but more of it in weight versus volume.


The only people that would MZFW out that far would be in a freighter configuration. The A339 now has the capability the A343 had, it is oversized for the original role the A333 had at 4000 nm, if they wanted to optimise for 4000 nm it would involve a smaller wing, and smaller engine however it would not be as effective at longer ranges,

Right, I was responding to the earlier point you'd made:

zeke wrote:
Changing to the new A320 engine would reduce fuel burn back closer to around 1-1.5 tonne per engine per hour, that means the fuel mass that is in the wing will be a lot lower as well as the reduced weight of the engine. The wing then would be significantly oversized resulting in the empty weight being much higher than it needs to be. It would still not be as capable as the A350-900 in range or payload.


Based on the above payload/range chart, the 343 and the 359 have similar payload/range near MZFW, so giving the 340 better engines would put it out ahead of the 359. At a system level it would still be less efficient though, so I doubt it would sell very well.
 
User avatar
zeke
Posts: 16130
Joined: Thu Dec 14, 2006 1:42 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 7:03 am

LH707330 wrote:
Based on the above payload/range chart, the 343 and the 359 have similar payload/range near MZFW, so giving the 340 better engines would put it out ahead of the 359. At a system level it would still be less efficient though, so I doubt it would sell very well.


The A359 lifts around 10 tonnes more payload, crew rest is not in the cargo hold meaning it can carry 3 more pallets or 6 more LD3s, more floor area to generate income.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
Sokes
Posts: 2775
Joined: Sat Mar 09, 2019 4:48 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 7:17 am

zeke wrote:
The A339 now has the capability the A343 had, it is oversized for the original role the A333 had at 4000 nm, if they wanted to optimise for 4000 nm it would involve a smaller wing, and smaller engine however it would not be as effective at longer ranges,

Anybody knows how much weight the new wing added?
What exactly changed? I guess one can't just add an extension. It has to be continuous metal sheet, or do I imagine it wrong?
Why can't the world be a little bit more autistic?
 
Sokes
Posts: 2775
Joined: Sat Mar 09, 2019 4:48 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 7:19 am

zeke wrote:
The A359 ..., crew rest is not in the cargo hold meaning it can carry 3 more pallets or 6 more LD3s, more floor area to generate income.

I didn't knew.
Anybody knows if same is true for B787?
Why can't the world be a little bit more autistic?
 
User avatar
Starlionblue
Posts: 20700
Joined: Fri Feb 27, 2004 9:54 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 7:32 am

Sokes wrote:
zeke wrote:
The A339 now has the capability the A343 had, it is oversized for the original role the A333 had at 4000 nm, if they wanted to optimise for 4000 nm it would involve a smaller wing, and smaller engine however it would not be as effective at longer ranges,

Anybody knows how much weight the new wing added?
What exactly changed? I guess one can't just add an extension. It has to be continuous metal sheet, or do I imagine it wrong?


AFAIK, it isn't really a new wing, but a tweak of the old one.

The major change was the new winglets. These change the lift distribution so there may have been changes to the wing spars.

There were also changes to the slats and some other bits which could be made now that a four-engine version does not have to be catered for.

It isn't quite that simple obviously, but you can "just add an extension". Wing spars and skins aren't necessarily one continuous piece. If we're talking just the winglets, they're probably bolted on to the end of the wing structure proper. I remember Boeing used to have a "winglet guy" whose job it was to mount the winglets on the 747-400. A sledgehammer was an integral part of the process.

At a guess, the new winglets don't weigh much more than the old ones. They are much larger but composite instead of metal. And we're probably talking the lightest part of the wing.

Sokes wrote:
zeke wrote:
The A359 ..., crew rest is not in the cargo hold meaning it can carry 3 more pallets or 6 more LD3s, more floor area to generate income.

I didn't knew.
Anybody knows if same is true for B787?


The 787 crew rests are also in the crown and does not take up cargo space, or main deck space beyond the access stairs.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Sokes
Posts: 2775
Joined: Sat Mar 09, 2019 4:48 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 8:17 am

I always thought the A330 fuselage was quite perfect.
Well, that sure is an advantage for the B787.
Where do pilots rest in an A330?
Why can't the world be a little bit more autistic?
 
User avatar
Starlionblue
Posts: 20700
Joined: Fri Feb 27, 2004 9:54 pm

Re: 2 vs 4 engines

Thu Jan 07, 2021 8:26 am

Sokes wrote:
I always thought the A330 fuselage was quite perfect.
Well, that sure is an advantage for the B787.
Where do pilots rest in an A330?


Depends on the configuration.

If there is a crew rest, it is in the cargo bay same taking up space as the A340.

Many A330s don't have a crew rest. On 3-crew flights, the resting pilot would use a lie-flat business class seat.

Mind you, Airbus might be able to design a crown area crew rest. I think there might be space.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Fri Jan 08, 2021 10:49 pm

zeke wrote:
LH707330 wrote:
Based on the above payload/range chart, the 343 and the 359 have similar payload/range near MZFW, so giving the 340 better engines would put it out ahead of the 359. At a system level it would still be less efficient though, so I doubt it would sell very well.


The A359 lifts around 10 tonnes more payload, crew rest is not in the cargo hold meaning it can carry 3 more pallets or 6 more LD3s, more floor area to generate income.

When did they up the max payload? It seems that some newer charts are quoting 52t for the 359 versus 42ish for the 343.
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Fri Jan 08, 2021 10:59 pm

Starlionblue wrote:
Sokes wrote:
zeke wrote:
The A339 now has the capability the A343 had, it is oversized for the original role the A333 had at 4000 nm, if they wanted to optimise for 4000 nm it would involve a smaller wing, and smaller engine however it would not be as effective at longer ranges,

Anybody knows how much weight the new wing added?
What exactly changed? I guess one can't just add an extension. It has to be continuous metal sheet, or do I imagine it wrong?


AFAIK, it isn't really a new wing, but a tweak of the old one.

The major change was the new winglets. These change the lift distribution so there may have been changes to the wing spars.

There were also changes to the slats and some other bits which could be made now that a four-engine version does not have to be catered for.

It isn't quite that simple obviously, but you can "just add an extension". Wing spars and skins aren't necessarily one continuous piece. If we're talking just the winglets, they're probably bolted on to the end of the wing structure proper. I remember Boeing used to have a "winglet guy" whose job it was to mount the winglets on the 747-400. A sledgehammer was an integral part of the process.

At a guess, the new winglets don't weigh much more than the old ones. They are much larger but composite instead of metal. And we're probably talking the lightest part of the wing.

Sokes wrote:
zeke wrote:
The A359 ..., crew rest is not in the cargo hold meaning it can carry 3 more pallets or 6 more LD3s, more floor area to generate income.

I didn't knew.
Anybody knows if same is true for B787?


The 787 crew rests are also in the crown and does not take up cargo space, or main deck space beyond the access stairs.

I'm pretty sure the old winglets were also composite. Many of the other changes like wing twist were subtle, but the WBF is noticeable. The WBF is a neo-only thing to help area ruling with the new engines, here you can see the differences (convenient, if ugly, that Airbus puts those little seals around the WBF)....

L/N 1867: note the short flaptrack canoes and the WBF running roughly parallel to the window belt:
https://www.airliners.net/photo/Shenzhe ... /6203855/L

L/N 1795: new winglets, same newer short flaptrack canoes, WBF has forward bulge and different shape:
https://www.airliners.net/photo/Airbus/ ... /6103035/L

Also, why did they insist on putting that stupid trash panda paint on the neo? I think it spoils the look of the 330 nose.
 
User avatar
Starlionblue
Posts: 20700
Joined: Fri Feb 27, 2004 9:54 pm

Re: 2 vs 4 engines

Sat Jan 09, 2021 12:53 am

LH707330 wrote:
Starlionblue wrote:
Sokes wrote:
Anybody knows how much weight the new wing added?
What exactly changed? I guess one can't just add an extension. It has to be continuous metal sheet, or do I imagine it wrong?


AFAIK, it isn't really a new wing, but a tweak of the old one.

The major change was the new winglets. These change the lift distribution so there may have been changes to the wing spars.

There were also changes to the slats and some other bits which could be made now that a four-engine version does not have to be catered for.

It isn't quite that simple obviously, but you can "just add an extension". Wing spars and skins aren't necessarily one continuous piece. If we're talking just the winglets, they're probably bolted on to the end of the wing structure proper. I remember Boeing used to have a "winglet guy" whose job it was to mount the winglets on the 747-400. A sledgehammer was an integral part of the process.

At a guess, the new winglets don't weigh much more than the old ones. They are much larger but composite instead of metal. And we're probably talking the lightest part of the wing.

Sokes wrote:
I didn't knew.
Anybody knows if same is true for B787?


The 787 crew rests are also in the crown and does not take up cargo space, or main deck space beyond the access stairs.

I'm pretty sure the old winglets were also composite. Many of the other changes like wing twist were subtle, but the WBF is noticeable. The WBF is a neo-only thing to help area ruling with the new engines, here you can see the differences (convenient, if ugly, that Airbus puts those little seals around the WBF)....

L/N 1867: note the short flaptrack canoes and the WBF running roughly parallel to the window belt:
https://www.airliners.net/photo/Shenzhe ... /6203855/L

L/N 1795: new winglets, same newer short flaptrack canoes, WBF has forward bulge and different shape:
https://www.airliners.net/photo/Airbus/ ... /6103035/L

Also, why did they insist on putting that stupid trash panda paint on the neo? I think it spoils the look of the 330 nose.


I see it now. Thank you.

I like the racoon paint. :)
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
BerenErchamion
Posts: 242
Joined: Thu May 28, 2015 12:44 am

Re: 2 vs 4 engines

Sat Jan 09, 2021 11:24 pm

Sokes wrote:
Has there ever been a case where four engines were chosen when two engines could have done the job?


Depending on how one interprets that question, A340? It was designed as essentially a four-engined A330 in a pre-ETOPS era.

That latter bit is why I say it depends on how you interpret the question, of course, because given that, one could argue that two engines could not legally do the job, even though there's no significant performance differences between the initial versions of the 340 and 330.
 
User avatar
Starlionblue
Posts: 20700
Joined: Fri Feb 27, 2004 9:54 pm

Re: 2 vs 4 engines

Sun Jan 10, 2021 1:44 am

BerenErchamion wrote:
Sokes wrote:
Has there ever been a case where four engines were chosen when two engines could have done the job?


Depending on how one interprets that question, A340? It was designed as essentially a four-engined A330 in a pre-ETOPS era.

That latter bit is why I say it depends on how you interpret the question, of course, because given that, one could argue that two engines could not legally do the job, even though there's no significant performance differences between the initial versions of the 340 and 330.


The A330/A340 was designed well into the ETOPS era. ETOPS-90 came in 1976 and ETOPS-180 in 1988. The A330 and A340 first flew in 1992 and 1991 respectively.

There are very significant performance difference between the original A330 and A340 versions. The A340 had about 35 tonnes higher MTOW, and significantly longer range.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
gloom
Posts: 547
Joined: Thu Jun 30, 2016 4:24 pm

Re: 2 vs 4 engines

Sun Jan 10, 2021 8:03 am

Starlionblue wrote:
The A340 had about 35 tonnes higher MTOW, and significantly longer range.


Original difference was even bigger. MTOW of initial versions of A330 was 212tons, 340 was maxed at 276tons. That's over 60 tons difference, almost 65.

Cheers,
Adam
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Sun Jan 10, 2021 4:05 pm

gloom wrote:
Starlionblue wrote:
The A340 had about 35 tonnes higher MTOW, and significantly longer range.


Original difference was even bigger. MTOW of initial versions of A330 was 212tons, 340 was maxed at 276tons. That's over 60 tons difference, almost 65.

Cheers,
Adam

276 only came in 1996 when Singapore pushed for it so they could make Paris non-stop. That's when the 342 stopped selling, because the 343 had enough range to cover 99% of what people wanted to fly. Prior to that, 257t was the max, which is still 45t more than the 330 at 212. That's either 40ish pax at a given range, or 5ish hours flying time at a given payload. That's why the 343 sold so well in the early years.
 
BerenErchamion
Posts: 242
Joined: Thu May 28, 2015 12:44 am

Re: 2 vs 4 engines

Mon Jan 11, 2021 6:17 pm

In the sense I'm using it, similar performance means ability to perform roughly the same missions. From this perspective, MTOW is irrelevant; what actually matters in terms of how it performs as a commercial vehicle is useful load, in which the differences between the two were minimal.

That said, I was thinking the 330-200 was the initial variant, and was comparing that to the 340-200 (which actually had slightly shorter legs than the 330-200) and -300 (which was similar to the 330-200). However, I erred in not realizing that the 330-300 was the first.
 
User avatar
zeke
Posts: 16130
Joined: Thu Dec 14, 2006 1:42 pm

Re: 2 vs 4 engines

Mon Jan 11, 2021 6:45 pm

LH707330 wrote:
276 only came in 1996 when Singapore pushed for it so they could make Paris non-stop.


The 276 tonne MTOW only came in after SQ got rid of theirs, we had 3 ex SQ aircraft. They would not have needed MTOW to get to Paris, that would have been around 12 hours which was a comfortable sector length in the A343.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
User avatar
Starlionblue
Posts: 20700
Joined: Fri Feb 27, 2004 9:54 pm

Re: 2 vs 4 engines

Tue Jan 12, 2021 1:51 am

BerenErchamion wrote:
In the sense I'm using it, similar performance means ability to perform roughly the same missions. From this perspective, MTOW is irrelevant; what actually matters in terms of how it performs as a commercial vehicle is useful load, in which the differences between the two were minimal.

That said, I was thinking the 330-200 was the initial variant, and was comparing that to the 340-200 (which actually had slightly shorter legs than the 330-200) and -300 (which was similar to the 330-200). However, I erred in not realizing that the 330-300 was the first.


I agree that "similar performance means ability to perform roughly the same missions", but the A340 could perform missions that the A330 didn't even get close to. For one thing, it could carry more than 50 tons more over the same distance.

Pure range isn't as important as useful payload over a given range.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Tue Jan 12, 2021 5:48 am

BerenErchamion wrote:
In the sense I'm using it, similar performance means ability to perform roughly the same missions. From this perspective, MTOW is irrelevant; what actually matters in terms of how it performs as a commercial vehicle is useful load, in which the differences between the two were minimal.

That said, I was thinking the 330-200 was the initial variant, and was comparing that to the 340-200 (which actually had slightly shorter legs than the 330-200) and -300 (which was similar to the 330-200). However, I erred in not realizing that the 330-300 was the first.


You getting that data from the payload/range charts? The first 332s at 230T had a brochure range of ca 6400 nm vs the 7300 of the 257T 342. They have the same tank capacity, so an empty 332 would go further than an empty 342, but with a realistic payload the 342 wins. Same story with the 788 vs 789: the small one goes further empty, but has a lower range with payload due to a reduced MTOW.

zeke wrote:
LH707330 wrote:
276 only came in 1996 when Singapore pushed for it so they could make Paris non-stop.


The 276 tonne MTOW only came in after SQ got rid of theirs, we had 3 ex SQ aircraft. They would not have needed MTOW to get to Paris, that would have been around 12 hours which was a comfortable sector length in the A343.


I just looked it up, turns out it was the 271T MTOW that they got. Per Norris and Wagner, "changes included strengthened landing gear and attachments, a beefed-up main wing box, and reinforcement of the pickup structure for the nose and main undercarriage legs." It's unclear whether further physical changes were needed to get the last 5T up to 276, or if that was done through some load alleviation software or other clever tricks.
 
User avatar
zeke
Posts: 16130
Joined: Thu Dec 14, 2006 1:42 pm

Re: 2 vs 4 engines

Tue Jan 12, 2021 6:08 am

LH707330 wrote:
I just looked it up, turns out it was the 271T MTOW that they got. Per Norris and Wagner, "changes included strengthened landing gear and attachments, a beefed-up main wing box, and reinforcement of the pickup structure for the nose and main undercarriage legs." It's unclear whether further physical changes were needed to get the last 5T up to 276, or if that was done through some load alleviation software or other clever tricks.


I’m pretty sure we operated them at 275 tonnes when we got them after SQ, and upgraded to 276 tonnes around 2008.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
LH707330
Posts: 2460
Joined: Fri Jun 15, 2012 11:27 pm

Re: 2 vs 4 engines

Tue Jan 12, 2021 6:20 am

zeke wrote:
LH707330 wrote:
I just looked it up, turns out it was the 271T MTOW that they got. Per Norris and Wagner, "changes included strengthened landing gear and attachments, a beefed-up main wing box, and reinforcement of the pickup structure for the nose and main undercarriage legs." It's unclear whether further physical changes were needed to get the last 5T up to 276, or if that was done through some load alleviation software or other clever tricks.


I’m pretty sure we operated them at 275 tonnes when we got them after SQ, and upgraded to 276 tonnes around 2008.

Probably a paperwork exercise then, doubt they'd have made further mods later on anyway. I suspect the beefed-up frame became the build standard anyway on the 343, which helped kill off the 342.
 
User avatar
zeke
Posts: 16130
Joined: Thu Dec 14, 2006 1:42 pm

Re: 2 vs 4 engines

Tue Jan 12, 2021 6:25 am

LH707330 wrote:
Probably a paperwork exercise then, doubt they'd have made further mods later on anyway. I suspect the beefed-up frame became the build standard anyway on the 343, which helped kill off the 342.


Think some landing gear work was required, seem to recall a red placard with “275 tonnes” on the main gear.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
BerenErchamion
Posts: 242
Joined: Thu May 28, 2015 12:44 am

Re: 2 vs 4 engines

Wed Jan 13, 2021 1:57 am

Starlionblue wrote:
BerenErchamion wrote:
In the sense I'm using it, similar performance means ability to perform roughly the same missions. From this perspective, MTOW is irrelevant; what actually matters in terms of how it performs as a commercial vehicle is useful load, in which the differences between the two were minimal.

That said, I was thinking the 330-200 was the initial variant, and was comparing that to the 340-200 (which actually had slightly shorter legs than the 330-200) and -300 (which was similar to the 330-200). However, I erred in not realizing that the 330-300 was the first.


I agree that "similar performance means ability to perform roughly the same missions", but the A340 could perform missions that the A330 didn't even get close to. For one thing, it could carry more than 50 tons more over the same distance.

Pure range isn't as important as useful payload over a given range.


You're absolutely correct, I jumped things a bit.

Who is online

Users browsing this forum: zanl188 and 22 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos