directorguy
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What Is Aircraft Range?

Sun May 17, 2009 4:55 pm

Range? We all keep hearing about it, using it, but how is it defined? Granted, you take factors like wind, aircraft weight/load into account etc. but it doesn't always add up.
Take the Airbus A330-200 for example. On paper it has range of 12,500 km/6749nm which means it could operate BOM-SEA nonstop; however I don't see anyone operating US West Coast-India with an A332:


Distance of BOM-SEA is 12,481 km

It's a close call, but the A330 doesn't operate routes nearly as long. When an airline like Turkish Airlines operates the A330-200 to ORD (12 hour flight) which is 8836 km, it is apparently restricted and a stretch for the airliner's capabilities. Is that distance a good 4,000km off the maximum range? Even when taking wind, weight, takeoff altitude etc, it shouldn't be that close to 12,500km.


It's all a big confusing-anyone care to discuss?
 
antonovman
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RE: What Is Aircraft Range?

Sun May 17, 2009 5:09 pm

Its how far it can fly. The range figures you are quoting are probably for an empty aircraft. As soon as you put pax on and more so cargo, the range is significantly reduced.
The heavier the aircraft the more fuel it burns, so the heavy it is the range is shorter
 
B747forever
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RE: What Is Aircraft Range?

Sun May 17, 2009 5:13 pm



Quoting Directorguy (Thread starter):
. When an airline like Turkish Airlines operates the A330-200 to ORD (12 hour flight) which is 8836 km, it is apparently restricted

well that can be because of the runway length at IST.
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DAL763ER
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RE: What Is Aircraft Range?

Sun May 17, 2009 8:05 pm

Big version: Width: 486 Height: 246 File size: 21kb


LHR-Darwin is 7490nm...is anyone ever going to fly Europe-Australia non-stop? A380 range is 8200nm. As Antonovman said, it's all related to pax, cargo, winds...Although not the case in IST-ORD, would you like to sit on an a/c for 16-18 hours?
 
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seabosdca
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RE: What Is Aircraft Range?

Sun May 17, 2009 8:12 pm

Aircraft range is how far the aircraft could fly:

- in still air
- with a full passenger load (the density of which can change between manufacturers and aircraft)
- with no additional cargo
- at the most economical speed and altitude.

Of course, this is a figure that ends up being very, very optimistic compared to real-world use, since aircraft don't really fly straight along the GC route; are affected by winds and non-optimal cruise speeds and altitudes; and tend to carry cargo.

A few examples:

Airbus quotes 6750 nm for the A332, but the longest route an A332 has regularly operated in the real world is LAX-AKL at 5652 nm (GC), and that is widely acknowledged to be close to the A332's real-world limits without restrictions.

Boeing quotes 7700 nm for the 772ER, but CO has occasionally faced weight restrictions on its 7009 nm (GC) EWR-HKG route.

Boeing quotes 5900 nm for the 763ER, but the longest route regularly flown with the type is LAX-SVO, at 5251 nm (GC).

The operational history of a given type will tell you much more about its real-world range than the quoted range number.

[Edited 2009-05-17 13:14:09]
 
Viscount724
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RE: What Is Aircraft Range?

Sun May 17, 2009 8:25 pm

As a rough figure you have to deduct about 15% from manufacturer's quoted range figures to obtain a real-world number that takes into account things like wind, temperature, the many airports not located at sea level, as well as cargo.
 
vikkyvik
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RE: What Is Aircraft Range?

Mon May 18, 2009 3:42 am



Quoting SeaBosDca (Reply 4):
Of course, this is a figure that ends up being very, very optimistic compared to real-world use, since aircraft don't really fly straight along the GC route; are affected by winds and non-optimal cruise speeds and altitudes; and tend to carry cargo.

Yep. Reason for that being that the manufacturers have to provide the airlines with an objective way to judge the performance of airplanes. So you quote the range for a standard set of conditions.

Among other things, airlines will look at the Payload-Range curve for an airplane. This will give you a more realistic idea of how the airplane can perform.

Here's the document that contains the Payload-Range curves (along with TOFL and LFL lengths) for the 777 (they start on the 3rd page of the PDF):

http://www.boeing.com/commercial/airports/acaps/777rsec3.pdf

Basically, you have a Max Payload horizontal line, then a Max Takeoff Gross Weight diagonal line, then a Max Fuel Capacity diagonal line. This curve tells you more about how much payload you can expect to carry on various missions.
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Pellegrine
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RE: What Is Aircraft Range?

Tue May 19, 2009 12:43 am



Quoting Directorguy (Thread starter):
Range? We all keep hearing about it, using it, but how is it defined?

How far an aircraft will go given the constants of ZFW and fuel load, and the variables of wind at altitude, airspace requirements, terrain clearance, etc.

Quoting Directorguy (Thread starter):
On paper it has range of 12,500 km/6749nm which means it could operate BOM-SEA nonstop; however I don't see anyone operating US West Coast-India with an A332:

The A330-200 does have 6750nm range at 52-54,000 lbs. payload considering an OEW of ~258,000 lbs and MTOW of 513,676 lbs. (233 tonnes). In your specific example this route would be hard pressed to be operated by a twinjet because of terrain clearance concerns with one engine out. As your GC map shows, the route travels NNE directly over the Himalaya mountain range, that would probably be off limits for a heavy twin engine airliner. This route also looks to cut across the western part of China which is a no-no as most Chinese airspace is still closed except for specific routes.

Quoting SeaBosDca (Reply 4):
A few examples:

Airbus quotes 6750 nm for the A332, but the longest route an A332 has regularly operated in the real world is LAX-AKL at 5652 nm (GC), and that is widely acknowledged to be close to the A332's real-world limits without restrictions.

Boeing quotes 7700 nm for the 772ER, but CO has occasionally faced weight restrictions on its 7009 nm (GC) EWR-HKG route.

Boeing quotes 5900 nm for the 763ER, but the longest route regularly flown with the type is LAX-SVO, at 5251 nm (GC).

The operational history of a given type will tell you much more about its real-world range than the quoted range number.

Building on what you said... I doubt any airline wants to operate an a/c type all the way up to it's "quoted range" (which is basically a midpoint on the payload side of the range curve. That way they have plenty of operational flexibility when it comes to things like high alt. winds, routings around weather, cargo, etc.
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Starlionblue
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RE: What Is Aircraft Range?

Tue May 19, 2009 5:39 am



Quoting Antonovman (Reply 1):
Its how far it can fly. The range figures you are quoting are probably for an empty aircraft. As soon as you put pax on and more so cargo, the range is significantly reduced.
The heavier the aircraft the more fuel it burns, so the heavy it is the range is shorter

Furthermore, if you fill it with pax and cargo, you can take less fuel or you'll hit the max take-off weight limit.
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