Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Cargo Aircraft Efficiency  
User currently offlinec5load From United States of America, joined Sep 2008, 917 posts, RR: 0
Posted (4 years 5 months 1 week 5 days 2 hours ago) and read 3556 times:

Why are some models of airplanes more efficient for carrying cargo than others? For example, the A332F is better than the A333F (if there ever was one) as far as weight-carrying capability. The 763ERF is better than the 764F. But in both of those examples, the larger airplane has more room inside than the other, so why wouldn't manufacturers build the larger model of that series to suit the needs of a cargo carrier. The 744F is capable, the MD-11F is capable, so why can't the 764 be capable or the A333 be capable?

One last example is the new Boeing KC-X tanker, which IIRC is built on a 762 frame with winglets. But wouldn't a 764 with the raked winglets and longer fuselage hold more cargo and fuel and still be able to go just as far if not further?


"But this airplane has 4 engines, it's an entirely different kind of flying! Altogether"
5 replies: All unread, jump to last
 
User currently offlineBMI727 From United States of America, joined Feb 2009, 15809 posts, RR: 27
Reply 1, posted (4 years 5 months 1 week 4 days 22 hours ago) and read 3503 times:

Quoting c5load (Thread starter):
A333F (if there ever was one)

There might be on a conversion basis, but it would most likely be used for hauling packages.

Quoting c5load (Thread starter):
But in both of those examples, the larger airplane has more room inside than the other, so why wouldn't manufacturers build the larger model of that series to suit the needs of a cargo carrier.

Because most of that extra room would be wasted on a flight of any length, as the aircraft would reach its maximum weight at a lower volume. This is why the 777F is built off of the 77L airframe, as it allows it a large payload and a greater range.

Quoting c5load (Thread starter):
But wouldn't a 764 with the raked winglets and longer fuselage hold more cargo and fuel and still be able to go just as far if not further?

Not likely for two reasons. First I think that there was a field length requirement that the other 767s would have trouble meeting, and second, using either of the longer 767 models could leave insufficient boom clearance on rotation.



Why do Aerospace Engineering students have to turn things in on time?
User currently offlinesunrisevalley From Canada, joined Jul 2004, 5126 posts, RR: 5
Reply 2, posted (4 years 5 months 1 week 4 days 2 hours ago) and read 3370 times:

Quoting c5load (Thread starter):
Why are some models of airplanes more efficient for carrying cargo than others?

There are a number of considerations. Very important are the Uniform Load Devices ( ULD's) that the industry has grown up around and that are interchangeable from carrier to carrier. Do a search on Google under "ULD's" to get some idea of all that are in use. IATA have a spec sheet on the various sizes. The Emirates brochure at http://www.skycargo.com/Images/B777F%20A4%20Brochure_tcm79-421138.pdf shows how efficiently the 777F space can be used with just a few ULD types. The ability of an aircraft type to be loaded as close to the max available volume with these contributes greatly to it's efficiency.
Cargo density is another issue. Different carriers haul different types of cargo and the density varies greatly starting as light as about 120kgf/m3 of ULD space for packet carriers. Another group are in the 150 to 170kg/m3 density for package carriers and so forth. At the other end of the scale is the example that one of the subscribers to the list quoted ; he flew for SQ Freight and one particular load was a one piece propeller shaft for a bulk freighter. I don't remember what it weighed but it was substancial.


User currently offlineViscount724 From Switzerland, joined Oct 2006, 25837 posts, RR: 22
Reply 3, posted (4 years 5 months 1 week 4 days 2 hours ago) and read 3369 times:

Quoting BMI727 (Reply 1):
Quoting c5load (Thread starter):
But wouldn't a 764 with the raked winglets and longer fuselage hold more cargo and fuel and still be able to go just as far if not further?

Not likely for two reasons. First I think that there was a field length requirement that the other 767s would have trouble meeting, and second, using either of the longer 767 models could leave insufficient boom clearance on rotation.

Another issue for the tanker is the ramp space required for parking, so overall length and wingspan are important criteria.


User currently offlinethegeek From Australia, joined Nov 2007, 2638 posts, RR: 0
Reply 4, posted (4 years 5 months 1 week 3 days 23 hours ago) and read 3334 times:

Not only would the extra hold space be wasted, but the extra fuselage weight would contribute to MTOW (and MZFW) and therefore actually reduce the amount of cargo which could be carried. It all comes down to the fact that cargo is denser than pax. Not sure why the 742F didn't work better based on the shrink 747SP either. Perhaps it was a too radical shrink.

User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3423 posts, RR: 4
Reply 5, posted (4 years 5 months 1 week 3 days 20 hours ago) and read 3293 times:

Quoting thegeek (Reply 4):
747SP either. Perhaps it was a too radical shrink.

747SP was a very comprimized design. Its only benifit over the 747-100 was extra range. The shorter fuselage cut lower cargo hold volume, and the wieght savings doesn't translate to payload. Oh and the 747 was designed around a fairly heavy cargo density so cutting volume to cut wieght isn't approprate.


Top Of Page
Forum Index

Reply To This Topic Cargo Aircraft Efficiency
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Best/Worst Aircraft Cargo Holds posted Wed Jan 28 2009 20:36:41 by TSS
Efficiency Of Aircraft Via SFC & SR posted Wed Jan 3 2007 16:23:18 by Corsair2
Small Cargo Planes For Large Aircraft Flights posted Sun Apr 23 2006 10:33:50 by QFA380
Why No C-130 Aircraft For Cargo Airlines? posted Fri Mar 18 2005 01:19:54 by PPVRA
Three Engine Aircraft Popular Cargo Airplanes posted Fri Apr 9 2004 15:02:16 by Beowulf
Do Aircraft Ever Get "earthed"? posted Wed Jun 9 2010 11:41:12 by speedbird9
Aircraft Development Costs posted Sat May 29 2010 12:30:31 by jamies80085
Economic Viability Of Operating With Old Aircraft? posted Fri May 28 2010 18:55:04 by c5load
Pressurization In Cargo Planes? posted Fri May 28 2010 16:45:29 by peteschiller
Max Range Of Aircraft At Mtow posted Thu May 27 2010 16:00:41 by vin2basketball

Sponsor Message:
Printer friendly format