Airline geeks question

forzaminardi

what's the difference between a 747-400 and a 747-306m ?

Jello_Biafra

I believe when Boeing uses a number in the ones place, it denotes what block the aircraft is from. It's common with military aircraft, you might hear of 'Block-20 F-16' or something to that effect. That would be an F16 of whatever spec, but from the 2nd or 20th block built. Changes are minimal if at all and I'm not really sure of the reason for building them in this manner.. quality control perhaps?

Now that I've typed all of that out, watch me be wrong.

MCSF

I thought that was passenger capacity.

Jello_Biafra

I don't think 737-500's can hold 500 people. :(

Lease

Give a star to the young-un.......almost.

The first number is always the series identifier. In this case, a 300 series (first of the extended upper deck). If the specification by a particular airline differs enough from the standard product, then Boeing gives the aircraft its own model number. In this case it is a 306m, meaning a 300 series to KLM's particular requirements, with the M (as always) specifying that it is a Combi.

A similar aircraft is the 747-338 of Qantas. Qantas usually specifies 747s with certain features that either make the airplane more suited to very long range, or - in that airline's particularly arrogant view of things - to overcome defficiencies in the design.

Other examples in the same theme:

747 - 341 (Varig)

747 - 329 (Sabena)

But RJ's question was 'what is the difference between a 747 - 400, and a 747 - 306m? The answer is plenty. Way too much to list here, but can be summarised as:
- Physically, the 400 has winglets (except freighter versions, and Domestic versions)

- The 400 has heaps more range

- The 400 has much more powerful engines and a much higher take-off weight

- The 400 is nicer inside, cause it's younger. Mind you, some are approaching 17 years in service.

[Edited on 17/1/2006 by Lease]