Why no stretched 747 in the past?

[LUNN]

Was there no need for s stretched version of the 747 atleast in the last 20 years if not earlier, Airbus are looking at the stretched A380 already I think it exists in concept too, so why wasnt a 747-500 required in the past?

[MCM]

Compare a 747-100 to a 747-400.

Then to a 747-800.

[turbotraker]

What about a 'double decker' 747?

[HalcyonDays]

There are several factors, but one was that the "stretch" occurred via the extended upper deck on the -300 and -400. There was otherwise no economic imperative to extend the airframe (eg., as noted above, the -100 versus -400 - virtually a new aircraft).

[decker1993]

I have "Airliner Color History" book on 747. Back in 1996 when 747-500/600 were in considertion, 747-600 would have been 278' long with wingspan of 251'. This caused some stirs with airport managers about handling 278' long 747s and air control were concerned about the wake-turbulences.
While several airliners showed interested, none of them were willing to comment to it plus market uncertainty and some delays- this pretty much killed the projects so Boeing decided to drop it in favour of long range and high-capacity variants 777.
Who knows- maybe those long 747s will come out as stretched variants of 747-8? Two things would have to happen- enough airlines interest in it and markets for it.

[Foxtrot]

^The proposed stretched variants of the 747, the -500X, -600X and the -700X (yes, there was a -700X Boeing had proposed) came with some problems. First, the aircraft would have trouble fitting in on ramps at many of the major hubs/gateways, as you can imagine, an aircraft that's longer than the 346/773 and even the 748 would likely cause some problems. Then also were development costs that were escalating to about $5 billion according to some reports, and with airline interest not there, Boeing had to cancel the project.