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a380900
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Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 12:40 am

I think Boeing planes tend to be lighter than Airbus for a comparable capacity. Is there a simple explanation?
 
FredT
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 2:06 am

Why do you 'think' they tend to be 'lighter'? Define the question. Do some research. Is it the ratio between MTOW and mean BEW you are looking at? (MTOW-MZFW)/MZFW? This is not hard to find data. By then you know the situation. Once that is accomplished, ask again and you will likely get informed answers.

Cheers,
Fred
 
TheSonntag
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 5:15 am

Yes, the B777 is lighter than the A380. Marvelous achievement  Wink

I honestly think this discussion will lead to nothing. Compare the A320 to the 737, you will NOT find a big difference.

The A340 is heavier than the 777, this is true, but you cannot claim that Boeings in general are lighter than Airbus aircraft.

Michael
 
N1120A
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 7:07 am

Quoting TheSonntag (Reply 2):
Compare the A320 to the 737, you will NOT find a big difference.

Every 737 is lighter per seat than every aircraft from the A32S family

Quoting TheSonntag (Reply 2):
The A340 is heavier than the 777, this is true, but you cannot claim that Boeings in general are lighter than Airbus aircraft.

The A340 is significantly heavier than the 777, the 764 is lighter than the A332 (though not as capable), the 737 is lighter than the A32S, shall I go on?
 
TheSonntag
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 9:03 am

Quoting N1120A (Reply 3):
The A340 is significantly heavier than the 777, the 764 is lighter than the A332 (though not as capable), the 737 is lighter than the A32S, shall I go on?

And the A300 is lighter than the 767. I know what you want to tell, but it really leads to nothing. With the exception of the 777, no Boeing product is lighter so that it makes a difference in a directly competing market.

Regards, Michael
 
mandala499
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 10:18 am

It does make a difference... in some places...
A320s don't sell here in Indonesia because the runways are in that marginal PCN that would support 734 ops and not 320... and 733 not 319s... coz the Boeings are lighter...

Unless you put the double bogey on the buses  Smile

Mandala499
 
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HAWK21M
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 3:53 pm

Quoting A380900 (Thread starter):
I think Boeing planes tend to be lighter than Airbus for a comparable capacity

What makes you say that.
regds
MEL
 
Shenzhen
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 6:00 pm

Because the aero guys have more weight in the decisions then the structuaral guys in engineering. Its always a battle... the structures want more, the aero guys want less.

Cheers
 
jush
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 6:33 pm

Quoting A380900 (Thread starter):
Why Are Boeing Planes Lighter Than Airbus Planes?

Is that so?? crappy topic.
 
aireuropeuk733
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Mon Sep 19, 2005 9:52 pm

It's all the hot air the Boeing salesmen speak  Wink

Sorry - couldn't resist!

AE733
 
mandala499
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 1:38 am

Just ran through the figures earlier... on the narrowbodies...
All Boeings are lighter in terms of OEW/seat based on max capacity up to the 738... Also better max payload per seat based on max capacity also... The 757 doesn't look so great and neither does the 739(nonER)... and all up to the 738 have higher MTOW, so you can use that payload for better range.

I guess the Airbuses are heavier because of the wider fuselage cross section (it's of composite/plastics? Imagine if it was metal!)... This gives better payload per seat on the A321 than the 739 and 752... Then you got the taller landing gear than the 737 and larger fans on the CFM56s (and I think the IAE is heavy too)... so... no wonder.

However, whether the better payload of the Boeing or the larger hold volume of the Airbus is better, it's up to the kind of stuff U carry down there.

There is one advantage the Boeings have over the Airbus where it does matter to sales... that is in areas where the runways are not strong. It was surprising that EADS "didn't know" of this weak runway problem of Indonesia until a meeting late last year... They kinda wished they pushed for the double bogey versions!

Mandala499
 
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Jetlagged
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 3:27 am

I don't have an axe to grind in the A v B weight debate. I just think some of the foregoing analysis has been way to simple and skewed.

Quoting Mandala499 (Reply 10):
Just ran through the figures earlier... on the narrowbodies...
All Boeings are lighter in terms of OEW/seat based on max capacity up to the 738... Also better max payload per seat based on max capacity also... The 757 doesn't look so great and neither does the 739(nonER)... and all up to the 738 have higher MTOW, so you can use that payload for better range.

Payload per seat, that's a new one.  Smile Simple calcs like this are not how airlines choose aircraft. Structural weight is not a parameter that is important to them. They will evaluate seat-mile costs and payload/range tradeoffs for their specific route structure and load factors.

Doing the maths per seat at max density is very misleading. The heavier structure will of an A319 supports higher MTOW than the equivalent 737. For example, the A319 OEW is 2 tonnes heavier than the 737-700 (similar max seating), however the MTOW is 5 tonnes heavier than the 737-700 in normal and high gross weight versions. So it's capacity for fuel and payload is 3 tonnes greater. (Note, data taken from A.net A/C Data pages, not manufacturer's published numbers)

Quoting Mandala499 (Reply 10):
I guess the Airbuses are heavier because of the wider fuselage cross section (it's of composite/plastics? Imagine if it was metal!)...

Airbus fuselages are metal (although the A380 has introduced GLARE). Both A and B use composites wherever they can. The A320 is not significantly wider than the 737 (both six abreast seating).

Quoting Mandala499 (Reply 5):
A320s don't sell here in Indonesia because the runways are in that marginal PCN that would support 734 ops and not 320... and 733 not 319s... coz the Boeings are lighter...

Are Indonesian runways that much weaker than the ones in Vietnam, for example? Vietnam Airlines operate A320 family aircraft, as do many others in the region. We're only talking about an extra 5 tonnes MTOW spread over 4 main wheels.

Don't take this the wrong way, but selling equipment in Indonesia is as much about having the right agent as it is about having the best product. Also the financing of the lease or purchase is a very big issue, which might swing an operator more than the aircraft economics or weight limits.

Back to the topic:
Raw structure weight is not the issue. Payload/range and seat mile costs for the routes flown are. Runway performance and weight limits are also key factors. Not to mention the financing and buy back deals offered. Note some operators have chosen both competing A and B designs for different routes in their network. Examples include Cathay Pacific, SIA and easyJet.
 
B2707SST
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 11:43 am

Quoting Jetlagged (Reply 11):
Raw structure weight is not the issue. Payload/range and seat mile costs for the routes flown are.

Strictly true, but structural weight has a direct impact on both payload/range and seat-mile costs. When an A340-500 has to lift 65,000 pounds more empty weight than a 777-200LR before a single passenger or drop of fuel is loaded, the effect is significant: you need bigger engines with higher fuel flow and hence higher operating costs, larger fuel tanks, a stronger airframe, etc., just to match the payload-range capability of a lighter aircraft.

A heavier OEW can be justifiable when it is needed to increase range or provide a higher maximum payload, hence the success of the A330-200 relative to the larger 767s. However, neither is true in the case of the 777 versus A340, a major reason why the 777 is outselling its counterpart. The 737NG and A320 seem to be more or less equally matched.

--B2707SST
 
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zeke
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 12:21 pm

Quoting Mandala499 (Reply 5):
It does make a difference... in some places...
A320s don't sell here in Indonesia because the runways are in that marginal PCN that would support 734 ops and not 320... and 733 not 319s... coz the Boeings are lighter...

Operators flying A320s into Indonesia of late include, Royal Brunei, Tiger, Silk Air, Jetstar, Valuair. Operators of past include Ansett and AWAIR.

Air Asia have ordered 100xA320's, Tiger have more coming as do Silk Air and Jetstar. Operators within 2 hours flying time of Indonesia have ordered about 120 A320 series aircraft recently.

With A320 fuel burn of 600-800 kg an hour less than a 734, that would be around 2,500,000 kg less fuel burnt a year in an A320 working on average 10 hrs a day. Fleet of 10 aircraft 25 million kg of fuel is a large saving, enough fuel for over 11000 hrs of A320 flying , or to put it another way you can fly 8 x 734 or 10 x A320 for the same fuel cost, with more pax and cargo uplifted on each A320.

If a runway cannot handle a A320, it will still get damaged by repeated 737 operations, on shorter runs it would be better to run a Q400/F28/RJ than a 732/731 if the runway strength was actually a consideration.
 
Aviation
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RE: Why Are Boeing Planes Lighter Than Airbus Plan

Tue Sep 20, 2005 1:20 pm

Even if Boeing's are lighter than Airbus' isn't a Airbus cheaper to purchase than Boeing but, a Boeing is much more Cheaper to service than a Airbus.

I believe this is going to be another A vs. B thread... weeping 


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Sorry Guys But Its Going This Way!

Thanks,
Aaron J Nicoli
 
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Jetlagged
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 2:29 pm

Quoting B2707SST (Reply 12):
Strictly true, but structural weight has a direct impact on both payload/range and seat-mile costs. When an A340-500 has to lift 65,000 pounds more empty weight than a 777-200LR before a single passenger or drop of fuel is loaded, the effect is significant: you need bigger engines with higher fuel flow and hence higher operating costs, larger fuel tanks, a stronger airframe, etc., just to match the payload-range capability of a lighter aircraft

OEW certainly has that effect as you say, but airlines are interested in payload, range and operating costs, not OEW in itself. Obviously if the structure weight is too high relative to MTOW the payload/range will become uncompetitive. Boeing don't even mention OEW on their site, which shows how useful a parameter it is.

You should examine OEW as a percentage of MTOW, to see how efficient the structure is. (The higher the percentage the less efficient the structure):

777-200ER 49.6%
A340-200 46.9%
A340-300 47%

767-200 48.1%
767-300 50%
A310-300 49.5%
A300-600R 53.4%

777-200 56%
777-300 53.5%
A330-200 52%
A330-300 53%

A320-200 54.8%
737-800 52.4%

A340-500 46.5%
777-200LR ??? (OEW not given by Boeing.com, nor listed on A.net data page)

This isn't the whole story, because it doesn't tell you how far the aircraft will fly at its MTOW, but it does show how relatively heavy each type is.

Regarding the A345 v 772LR, the A345 carries more pax slightly less far than the 7772LR (9000 nm versus 9240 nm). It uses more fuel overall, but about the same on a per passenger basis. You say the OEW of the Airbus is 65,000 lb more. That make the 777-200LR OEW about 311,000 lb. That is less than the 777-200ER (314,000 lb), which I doubt due to the more powerful and heavier engines on the LR version. Given the extra span, structural strengthening, heavier engines, I'd guess the OEW would be at least 320,000 lb. This figure gives a OEW to MTOW percentage of 42.5%, an impressive reduction on the basic 777-200 and 777-200ER. I can only assume the basic 777's have very conservative MTOWs.

This is a highly complex area, and airlines study the performance brochures long and hard before deciding on their choices. You can't see the whole picture without knowing how far the aircraft can fly with max payload and how far it can fly on max fuel. OEW per passenger is a completely meaningless figure in all this
 
GQfluffy
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 3:24 pm

Quoting Jetlagged (Reply 15):
777-200 56%
777-300 53.5%
A330-200 52%
A330-300 53%

And you're comparing the 773 with the other three why? Comparing the 777-200 with the A330 is pretty marginal as well, but I do understand why
 
mandala499
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 4:25 pm

Jetlagged,
Those numbers I just drummed up for fun... No practical applications. And the max density was used because that would be the max permissible seats that can be shoved into the aircraft... anything else is airline option...

Regarding the runways & Airbus in Indonesia... they've tried selling here for yonks... but again technical issues came up... But most of the issues were the fears of the advanced technology... It was only apparent after that meeting what the problem was...

The buses weren't able to carry the same payload range as the 737s out of the weaker runways... if the airports here have flexible category Bs, then bus v boeing don't matter, but for F/C and F/D, it matters... one or 2 PCN numbers can make a cargo department smile or cry.

The problem is that the runway strength limits are more suited to the 737 classics and the NGs I was told (haven't checked this myself) have less penalties than the A32x.

Zeke,
Ansett flew the A320 to DPS only... big airport.
AWAir v1.0 flew their A320 CGK, MES, BPN, SUB, DPS... that are major airports, not a problem... And the 320 was flown to replace the A310 they flew.
RBI only to SUB, DPS and CGK... and now mainly 319s.
Tiger to Padang (where 1 hr trip is about all it can take on payload).
Valuair to CGK... again, not a factor.
Jetstar to Indonesia? Now that's new  Smile

The current AWAir is now considering whether to take the A320s from Air Asia or take the 733s... As of the latest from inside the company, it'll be the 733s, again for that reason. Their current routes can take the 320 but the future routes? Who knows.

A lot of the runways have been retested to see if they can take higher loads (thanks to Lion wanting to bring their MD80s everywhere)...

Semarang, can only take 732/5... and only recently there has been SRG-SIN/KUL (forgot).
Pontianak, same as above, and can't take 733 with weight penalties... The longest route is a 50m 732/5 ride... it can't take a fully loaded 732.

The other airports around can only take 734/320 for 1hr flights... but most of these are >1hr away from Jakarta.

Q400 = too expensive
F28s = pax know their age
CRJ = too expensive
732 = the prevalent type, but age is showing.

Now the urge is to move to the 150 seaters to keep ASM costs down. So far no 320s have made it here to stay... Would love to see some buses here though  Smile

that would be around 2,500,000 kg less fuel burnt a year in an A320 working on average 10 hrs a day

It could also mean a loss of the same amount in cargo... but that's a different matter....  Smile Without good leasing packages, no matter if you have a perfect plane, it ain't gonna sell...

Mandala499
 
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zeke
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 7:09 pm

Jetlagged good guess, the 777-200LR OEW currently used for planning is 320,000 lb from http://www.boeing.com/assocproducts/aircompat/faqs/lcglcn.pdf

Mandala499,

Seen a Jetstar A320 in CKG in December last year. Silk Air go to a few regional ports also. I was thinking of where Bouraq and Mandala go with 737's, thought most could handle an A320.

50 nm sectors should not be done with jets, turboprops would be way cheaper. A Q400 would be faster and cheaper than a 737 over a 50 nm sector, and quicker to turn around.

But reading between the lines, anything that costs money like new aircraft to good runways will not happen.
 
mandala499
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Tue Sep 20, 2005 10:01 pm

Zeke,
They're not flying to CGK anymore... maybe it was a trial flight.

Silk Air flies to: MES PLM SOC AMI MDC BPN... AMI is the weakest runway of them all... served by 319s. PLM can handle the 320 coz it's a short flight and the runway has been completely rebuilt. PDG used to be served by MI's own planes but now codeshares with GA... they used the 319s... PKU was closed when they went from Fokkers and Boeings to the Airbuses because the runway then was too weak, but now rebuilt... and yes it can take the 320 for <2h trips... small cargo for departure though (the 734s also got the limitations).

Sorry, with Pontianak is 50 mins sectors (apologies).

I'm actually going through planning for an operations serving the east of the country. Sad to say that the airbuses won't be able to land to where I'm flying anytime soon... but after going through the various operational costs, those <60 seaters are expensive! Even the props! It's just feasible with the current fuel prices, but 12 months ago I'd be laughed at proposing big props to serve the region.

Back to the topic, there's a massive but unpublicised program to improve the airfields infrastructure here. Airbus will eventually get some sales for narrowbodies here... just not for the time being (add the market environment too)... weight and price... I expect Boeing's almost total dominance here will recede as more improvements come.

As we've discussed for the case in Indonesia, Airbus is currently at a disadvantage coz of the weight, but with the NGs heavier than the classics, it'll just be a matter of time before that disadvantage is eroded...

Asia Pacific sales for Airbus and Boeing I'm sure are quite happy that Fokker had closed down and remained closed... Otherwise this country could be dominated by the F100s and most airports will still be less than PCN 30FCYT or 30FDXT....

Mandala499
 
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Jetlagged
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Wed Sep 21, 2005 1:07 am

Quoting GQfluffy (Reply 16):
And you're comparing the 773 with the other three why? Comparing the 777-200 with the A330 is pretty marginal as well, but I do understand why

I only categorised them approximately to demonstrate the point. There are so many combinations it's hard to directly compare like with like without spending hours studying the detail. (Which is why airline consultants make so much money Big grin )

What the numbers do show is just how structurally efficient the A340 is generally, very far from being overweight. Interesting how well the 767 compares too. Presumably the 777-200LR figures show how much growth potential there was in the initial design.

In the A v B debate there is no winner, each manufacturer has some outstanding designs and to be prejudiced one way or the other is very short sighted. The slow climb rate of the A340 clouds peoples judgement, but it's not because it is heavy, it's because it has four engines, so less installed thrust than the equivalent twin.

On a very long haul, I'd rather be in a quad than a twin if there's an engine failure. To paraphrase a better engineer than me, the only reason I choose to fly in four engined aircraft is that there are no five engined ones.
 
zvezda
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Thu Sep 22, 2005 6:55 am

Quoting Jetlagged (Reply 15):
Regarding the A345 v 772LR, the A345 carries more pax slightly less far than the 7772LR (9000 nm versus 9240 nm). It uses more fuel overall, but about the same on a per passenger basis. You say the OEW of the Airbus is 65,000 lb more. That make the 777-200LR OEW about 311,000 lb. That is less than the 777-200ER (314,000 lb), which I doubt due to the more powerful and heavier engines on the LR version. Given the extra span, structural strengthening, heavier engines, I'd guess the OEW would be at least 320,000 lb. This figure gives a OEW to MTOW percentage of 42.5%, an impressive reduction on the basic 777-200 and 777-200ER. I can only assume the basic 777's have very conservative MTOWs.

According to Boeing's website, the OEW of the B777-200LR is 145.1 metric tonnes.
 
mikkel777
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Thu Sep 22, 2005 4:50 pm

Quoting Jetlagged (Reply 15):
A345 carries more pax slightly less far than the 7772LR

This is very not true!
If an airline choose the same pitch and seatwidth, the T7 have room for more passengers.
 
A350
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Fri Sep 23, 2005 12:22 am

These simple OEW or OEW/MTOW numbers just say nothing. There are other factors like aerodynamics or the efficiency of the engines.

Following to the logic "low OEW/MTOW is always good" or "low OEW is always good" measures like winglets or higher bypass engines would decrease efficiency. This is totally crappy.

A350
 
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Jetlagged
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Fri Sep 23, 2005 12:27 am

Quoting Mikkel777 (Reply 22):
This is very not true!
If an airline choose the same pitch and seatwidth, the T7 have room for more passengers.

It's not about space, but weight. I got the pax and range numbers from the respective Airbus and Boeing sites.
 
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Jetlagged
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RE: Why Are Boeing Planes Lighter Than Airbus Planes?

Fri Sep 23, 2005 12:51 am

Quoting A350 (Reply 23):
These simple OEW or OEW/MTOW numbers just say nothing. There are other factors like aerodynamics or the efficiency of the engines.

Not nothing, but not the whole story either, and I said as much in my posts. OEW/MTOW is a measure of structural efficiency. Not everything I grant you but without an efficient structure, payload and fuel capacity will be severely limited. The thread starter implied all Airbus were relatively heavy aircraft, I was trying to show this is not always the case.

To repeat, airlines look at payload, range and costs per seat mile. This includes the effect of things like aerodynamic drag and engine fuel consumption. MTOW is important as far as the runways to be used is concerned (no point in a high gross weight if the runway length is limiting it). MTOW-OEW tells you how much payload and fuel you can carry. OEW itself is contributory, but no aircraft can fly in that condition (no fuel  Smile ) so it is not a performance parameter.

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