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Topic: An Airliner That Burn 3 Time Less Gas Than A 737
Username: 747400sp
Posted 2006-06-21 18:06:04 and read 6124 times.

Right before the Concorde was retired, a travel reporter for the LA times said the Concorde burns 3 time more gas than a 747 burns. So I looking for a airliner that burns 3 time less gas than a 737, is there such a airliner?

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Oly720man
Posted 2006-06-21 18:20:33 and read 6112 times.

probably a small one like the emb 145

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Fr8Mech
Posted 2006-06-21 18:23:02 and read 6109 times.

Why do you even suspect one exists?

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: DH106
Posted 2006-06-21 19:10:50 and read 6081 times.

Quoting 747400sp (Thread starter):
So I looking for a airliner that burns 3 time less gas than a 737, is there such a airliner?

I assume you're talk comparible capabilities - number of passengers etc.
Well, surely if it did exist then every airline would be buying it and not the 737?

Quoting Fr8Mech (Reply 2):
Why do you even suspect one exists?

Exactly!

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: HAWK21M
Posted 2006-06-21 20:40:13 and read 6044 times.

By Gas Im sure you mean ATF.
I don't think so else The B737 would not be selling so well.
regds
MEL

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Seanp11
Posted 2006-06-21 21:11:24 and read 6036 times.

Quoting 747400sp (Thread starter):
Right before the Concorde was retired, a travel reporter for the LA times said the Concorde burns 3 time more gas than a 747 burns. So I looking for a airliner that burns 3 time less gas than a 737, is there such a airliner?

Your logic is a bit faulty, the concorde was a specialized a/c to go supersonic at the expense of economy, and the 747 was optimized for economy. That doesn't imply that there are other a/c that are like this. But to answer your question, probably a number of the smaller turboprops, like the DHC-8-400 probably burn less fuel than the 737, however these a/c do not have the size or cruise speed or altitude of the 737.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Kaddyuk
Posted 2006-06-21 21:21:02 and read 6027 times.

You need to compare TSFC (Thrust Specific Fuel Consumption) to get the true efficiency of an engine. I doubt you'd get an aircraft with a TSFC 1/3rd that of a B737.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: David L
Posted 2006-06-21 21:27:50 and read 6021 times.

Quoting 747400sp (Thread starter):
the Concorde burns 3 time more gas than a 747 burns

Was that over the same distance or in the same time?

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: StealthZ
Posted 2006-06-22 03:49:41 and read 5979 times.

You can't burn 3 times less...

If plane A burns X fuel and plane B burns 3 times as much that is a 200% increase in consumption.

Reversing that - Plane A uses 66% less fuel than plane B.

It is impossible to burn 3 times less fuel, the theoretical maximum is 100% less.. unless of course you have some miraculous device that actually makes fuel.

That would sell well!!

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: David L
Posted 2006-06-22 11:55:29 and read 5896 times.

Quoting StealthZ (Reply 8):

I've been biting my tongue very hard on that! It's a commonly used expression but I agree on the pedantic level.  Smile

  • Plane A burns x fuel
  • 3 times as much is 3x
  • 3 times less than x is x-3x = -2x


Plane B would have to produce twice as much fuel as plane A burns!

Sorry, 747400sp, I know what you meant.  Smile

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 7
Username: Oryx
Posted 2006-06-22 12:40:44 and read 5880 times.

Quoting Kaddyuk (Reply 6):
You need to compare TSFC (Thrust Specific Fuel Consumption) to get the true efficiency of an engine. I doubt you'd get an aircraft with a TSFC 1/3rd that of a B737.

That's only part of the question as there may be a plane with a lower demand in thrust per passenger. I believe a good candidate would be a big and slow turboprob. Unfortunate (for this thread) it is more economic from a financial point of view to fly a Ma = 0.85 than to fly and optimize for Ma = 0.3.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Dw747400
Posted 2006-06-22 23:18:37 and read 5769 times.

Quoting David L (Reply 9):
Plane B would have to produce twice as much fuel as plane A burns!

You just need a really big one of these with a refinery on top:

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Miller22
Posted 2006-07-05 16:16:19 and read 5525 times.

Q400.

Other than that, you're not going to find a jet that burns three times less gas than a 737.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: SlamClick
Posted 2006-07-05 16:55:16 and read 5508 times.

Quoting StealthZ (Reply 8):
You can't burn 3 times less...



Quoting David L (Reply 9):
I agree on the pedantic level.

I don't think it is really 'pedantic' at all. I consider myself a fairly bright boy and I've NEVER understood the 'three times less' statistic I hear from time to time.

Quoting David L (Reply 9):
Plane A burns x fuel
3 times as much is 3x
3 times less than x is x-3x = -2x

Plane B would have to produce twice as much fuel as plane A burns!

Now I DO understand it. This wonderful airplane motors along creating fuel.

I also understand why the 737 continues to sell better than this theoretical airplane. It's really pretty simple. The damn thing creates so much fuel during flight that you have to land all the time to offload it! Hell to keep schedule with a thing like this.

The only reason this theoretical airplane is still in production is that the USAF wants it as a tanker. It could take off empty and by the time it reaches the inflight refueling point it would have surplus fuel to deliver. The only reason they don't have it yet is because the Congresspeople in the appropriations committee think the US Budget works the same way and don't understand what is so wonderful about the principle.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Kaddyuk
Posted 2006-07-05 16:58:15 and read 5506 times.

Quoting SlamClick (Reply 13):
The only reason they don't have it yet is because the Congresspeople in the appropriations committee think the US Budget works the same way and don't understand what is so wonderful about the principle.

Now Now Slam, this is Tech Ops... NOT Off Topic  Wink

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: SlamClick
Posted 2006-07-05 17:14:37 and read 5500 times.

Quoting Kaddyuk (Reply 14):
this is Tech Ops... NOT Off Topic

I'm sorry. I lost my usual self-control for a moment.  Smile

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Zeke
Posted 2006-07-05 17:39:17 and read 5487 times.

EMB-145 burns about 22% fuel per hour of a 737-300.
F100 burns about 32% fuel per hour of a 737-200.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: A342
Posted 2006-07-05 20:58:48 and read 5429 times.

Quoting Zeke (Reply 16):
EMB-145 burns about 22% fuel per hour of a 737-300.

Really ? This means you could fly 4.5 E145s or one 733 with the same amount of fuel. In a high-density config you'd have 225 vs. 150 pax. But somehow I doubt this, the 733 fuel burn can't be that high.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: David L
Posted 2006-07-05 22:55:55 and read 5400 times.

Quoting Dw747400 (Reply 11):
You just need a really big one of these with a refinery on top:



Quoting SlamClick (Reply 13):

 biggrin 

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Kaddyuk
Posted 2006-07-06 00:27:47 and read 5379 times.

Quoting Zeke (Reply 16):
EMB-145 burns about 22% fuel per hour of a 737-300.
F100 burns about 32% fuel per hour of a 737-200.

This does not mean that they are more efficient aircraft, just smaller...

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Zeke
Posted 2006-07-06 03:48:58 and read 5348 times.

Quoting Kaddyuk (Reply 19):
This does not mean that they are more efficient aircraft, just smaller...

The question was

Quoting 747400sp (Thread starter):
So I looking for a airliner that burns 3 time less gas than a 737, is there such a airliner?

I provided an answer to that question.

Quoting A342 (Reply 17):
Really ? This means you could fly 4.5 E145s or one 733 with the same amount of fuel. In a high-density config you'd have 225 vs. 150 pax. But somehow I doubt this, the 733 fuel burn can't be that high.

Info I had from 'Civil Jet Aircraft Design' (ISBN 034074152X) book was that the 733 burns 3890 kg/hr EMB-145 880 kg/hr. I have since looked at data from USA operators (American Eagle, ExpressJet, TransStates, Mesa, Comair, Skywest, Pinnacle, Atlantic Southeast, Atlantic Coast, Air Wisconsin) shows

EMB135 1062 kg/hr
EMB140 1089 kg/hr
EMB145 1053 kg/hr
CRJ200 1008 kg/hr

I cannot find similar data for the 733 off hand, its been grouped together with the 737-700. I also think 3890 kg/hr seems high, I would have expected about 1600-1700 kg/side.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: A342
Posted 2006-07-06 21:08:42 and read 5259 times.

Quoting Zeke (Reply 20):
I cannot find similar data for the 733 off hand, its been grouped together with the 737-700. I also think 3890 kg/hr seems high, I would have expected about 1600-1700 kg/side.

In a book about airliners which I have it says 2900 liters/hour for the 734. Also, in a .pdf file published by BA about their fleet, the figure was in that ballpark. Unfortunately, I incidentally deleted it, so I'm not sure.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Prebennorholm
Posted 2006-07-07 01:38:17 and read 5212 times.

If we remove SlamClick's congressmen and the US budget from the figures and define 3 times less fuel as one third the fuel, then there are a few options:

We just ask the Boeing aerodynamic people to improve the 737 to have a lift to drag ratio of roughly 60:1 instead of 20:1. And hang a pair of Lear Jet engines under the wing.

Another option would be to improve the CFM56-7B engine to convert 45% of the energy in the fuel into thrust instead of only 15%. Wasting "only" 55% of the energy instead of 85% seems like a brilliant idea.

A good starting point would also be to reduce the 737 empty weight to one third and put the passengers on a 67% weight reduction diet prior to boarding.

 angel 

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Timz
Posted 2006-07-07 18:18:58 and read 5119 times.

Quoting A342 (Reply 17):
the 733 fuel burn can't be that high.

Stroud gives some figures for a 737-436 LHR-GLA-LHR trip in 1993. Northward the "average" cruise consumption was 2100 kg/hr at M0.72 FL310, southward the same consumption at M0.74 FL370. On the northward trip they burned 2200 kg from brake release to end of landing run -- airborne time was 51 minutes.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: A342
Posted 2006-07-07 21:28:37 and read 5085 times.

Quoting Timz (Reply 23):
Stroud gives some figures for a 737-436 LHR-GLA-LHR trip in 1993. Northward the "average" cruise consumption was 2100 kg/hr at M0.72 FL310, southward the same consumption at M0.74 FL370. On the northward trip they burned 2200 kg from brake release to end of landing run -- airborne time was 51 minutes.

Those numbers definitely sound more reasonable. Thank you.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Zeke
Posted 2006-07-08 14:26:30 and read 5015 times.

Quoting A342 (Reply 24):
Those numbers definitely sound more reasonable. Thank you.

Look at the speeds, 0.72 is fairly slow.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: A342
Posted 2006-07-08 19:50:53 and read 5012 times.

Quoting Zeke (Reply 25):
Look at the speeds, 0.72 is fairly slow.

Sure it is, but with these fuel prices nowadays, airlines let their aircraft fly slower so that fuel burn is reduced. On short flights the slower speed is hardly noticeable.

But what would be the burn at Mach 0.78, which IIRC is the standard for narrowbodies ?

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Lehpron
Posted 2006-07-09 10:01:27 and read 4923 times.

Quoting David L (Reply 9):
3 times less than x is x-3x = -2x

3 times less than x is x/3 or one-third of x. Less isn't always subtraction.

Quoting DH106 (Reply 3):
Well, surely if it did exist then every airline would be buying it and not the 737?



Quoting HAWK21M (Reply 4):
I don't think so else The B737 would not be selling so well.



Quoting StealthZ (Reply 8):
That would sell well!!

You people are making dangerous assumptions to say that. Such aircraft exist but as Seanp11 says:

Quoting Seanp11 (Reply 5):
however these a/c do not have the size or cruise speed or altitude of the 737.

Such efficiency is mainly...well, I was going to say 'about the engine', and while the scale of the airplane is irrelevant, shape isn't. To me shape is everything; a plane can be designed to take an engine designed for one plane and end up have a completely set of performance parameters, if not be better. But if doing so is not worth the cost, then why do it at all? This is how Sonic Cruiser turned into 787. Heck, if a company has enough investment, market doesn't matter. Ask Airbus, they know what I'm talking about.  Wink

Quoting Kaddyuk (Reply 6):
I doubt you'd get an aircraft with a TSFC 1/3rd that of a B737.

...in operation circa year 2006. Careful there, what you're saying can be interpreted as we cannot get an aircraft to do that, ever. It's only a matter of money, in my view time is less of an issue when things become priority. Just because it aint out doesn't mean it aint happenin. Big grin

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: Mpsrent
Posted 2006-07-10 18:15:27 and read 4805 times.

Quoting Prebennorholm (Reply 22):
A good starting point would also be to reduce the 737 empty weight to one third and put the passengers on a 67% weight reduction diet prior to boarding.

A 67% weight reduction for passengers...now that is funny.   

[Edited 2006-07-10 18:16:59]

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: David L
Posted 2006-07-10 23:25:55 and read 4763 times.

Quoting Lehpron (Reply 27):
3 times less than x is x/3 or one-third of x

No it's not. See the arguments above.  Smile

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: WildcatYXU
Posted 2006-07-11 03:55:43 and read 4740 times.

Quoting SlamClick (Reply 13):

SlamClick, it was so funny. I can't help it, you have to join my RU list

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: EGTESkyGod
Posted 2006-07-17 15:47:41 and read 4510 times.

Quoting 747400sp (Thread starter):
Right before the Concorde was retired, a travel reporter for the LA times said the Concorde burns 3 time more gas than a 747 burns.

That's not accurate, I'm afraid. For example, between LHR and JFK.....

Concorde burnt about the same amount of fuel going between London and New York as a 747 did. However, Concorde burnt it a lot faster as it got there faster too. And Concorde could have 100 people on board whereas a 747 could have 400 people.

At Mach 2, Concorde's Olympus 593 engines were the most fuel efficient on the planet, however at subsonic speeds, she was less efficient as the characteristics of a delta wing at slow speeds require more power, which equals more fuel burn.

Had Concorde B model ever been manufactured, the engines that were being developed for her would have been more fuel efficient still, thus making Concorde B a more economic aircraft.

Topic: RE: An Airliner That Burn 3 Time Less Gas Than A 737
Username: David L
Posted 2006-07-17 17:23:33 and read 4497 times.

Quoting EGTESkyGod (Reply 31):
Concorde burnt about the same amount of fuel going between London and New York as a 747 did. However, Concorde burnt it a lot faster as it got there faster too.

Thank you. That's what I was fishing for here...

Quoting David L (Reply 7):
Quoting 747400sp (Thread starter):
the Concorde burns 3 time more gas than a 747 burns

Was that over the same distance or in the same time?


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