Why not extend the upper deck of the 747-8?

You think when Boeing was competing against the A380, that they would extend the upper deck all the way to the back?



I mean look at it, its only about a third or half of its total length. I think the 747 would look great if they extend that "hump" all the way to the back.

Doing so would require significant re-engineering of the airframe. Likely the center of gravity would shift substantially towards the rear of the plane meaning the wings may need repositioned. The rudder assembly would need modification to ensure sufficient control surface would remain in the airstream. The added weight would probably result in serious reduction in the load capacity of the plane.
Keep in mind also that the 747 is a decades old design. Designing a new plane was likely going to be cheaper overall to accomplish that redesigning an existing airframe. It's more than just extending some cowlings, spars and such.

Ah that explains it. I figured that Boeing was constantly changing and modifying the 747 airframe that they would also include extending the upper deck, but as you said that would practically change the whole plane to the point that it would be a whole new plane.

Is there a replacement for the decades old design in the near future? A 747 resemblance but much bigger?

reply to post by deltaboy


The 747-8 is the replacement for the 747-400 and earlier versions. Boeing hasn't officially announced any plans for a similar sized or bigger replacement that I'm aware of.

Yhea as abecedarian said, I think that was pretty much at the limit of what was practical back when the 747 was designed (and considering it entered service in the 70's).

I heard the reason for the hump in the first place was to raise the cockpit to enable the main deck to run the length of the aircraft. They then realised there was a bit more seating space to be had behind the cockpit... So really they already have extended the hump as much as they could.

It's a great plane though - If it ain't broke and all that

reply to post by Zaphod58


Ever seen that movie Casino Royale? That Skyfleet S570? That resembles a 747 but has a double deck all the way to the tail section. Thats something I had in mind. Fiction yes, but perhaps practical.

reply to post by deltaboy


Boeing and Airbus were both working on a Super Jumbo at the same time. Boeing decided that it wasn't going to ever be a big seller, and went with the 747-8 instead of a 5-800+ seater. Airbus decided that it was going to be profitable and built the A380. I wouldn't expect to see a Super Jumbo from Boeing any time in the near future, unless the A380 sales pick WAY up.

Boeing have also announced its delayed - and they are only selling 28 of the 747-8I version anyway to 1 customer , who privately are a bit jittery for being the only operator of the type , given the success of the A380.

www.jamesbondmm.co.uk...

Here is some pics of the plane in the movie, I was wrong when I said it was extended all the way to the back.

Originally posted by Harlequin
Boeing have also announced its delayed - and they are only selling 28 of the 747-8I version anyway to 1 customer , who privately are a bit jittery for being the only operator of the type , given the success of the A380.

While the A380 has been somewhat successful, I wouldn't call it hugely successful. Break even was originally at 250 aircraft. As of November 30, they had 197 orders. Break even has reportedly gone higher than 450 aircraft not with the problems with the dollar and other issues.

Boeing needs to get off their butts and get the 787 flying. They have a lot of orders for it, but they're in danger of losing them. The 787 has the potential to be a great airframe, like the A380 could eventually become, but Boeing needs to get their butts off their chairs and get it finished.

totally off topic: flightglobal have an excelent poll running ; which will fly first , a Virgin 787 or a Virgin galatic space tourist

The Boeing 747 was originally designed with a full length double deck in the 1960's but Boeing ditched the idea.

Boeing also proposed full length double deck versions in the 1970's and 1980's before building the -400.

They have never found it worthwhile to proceed with it. In a description of the -300 before it flew (the first version with the stretched upper deck), Boeing described it as being like mounting a 737 on the roof.

Here are some stages of 747 design, and Boeing weren't the only ones thinking this way in the 1960's (bottom pic)

Double deck reveal;



single deck, mild hump;



And we're there!



bonus image;



And from 1982;



[edit on 14-12-2008 by waynos]

reply to post by waynos


Nice post waynos and starred.
Great to see you around.

The other issue with that is as noted before the 747 is a decades old design. There simply is not much more stretch left in the airframe. Also the inital design was a product of the time and the realities they faced. The 747 was never intended to spend much time as a passanger jet. It was a stop gap untill SST took over then it was going to relegated to cargo. That was launch customer Pan Am's intent.

You also have a fundemental difference in the forecasts of both airlines. Airbus with the A380 is designed for high volume slot limited hubs. Think Dubai to Heathrow etc. If you only have to fly one A380 as opposed to one 747-400 and a 777 you save money.

Boeing forcasts point to point with smaller volumes hence the 787.

Who is right? Both. Airbus has been forced to compete with the A350 while Boeing has chosen not to go after the A380 directly and is trying to siphon off sales for carriers that are looking for an inbetween the 777 / A340 and the A380. To try to develop a direct competitor would be too little too late at this stage.



[edit on 12/14/08 by FredT]

Its decades old design and yet waynos has posted pics of a concept of the design that has a double deck for the 747.

Originally posted by deltaboy
Its decades old design and yet waynos has posted pics of a concept of the design that has a double deck for the 747.

Planes go through alot of desing phases and proposals. The inital design was from the early 60's The last double deck design was dated 1982. Boeing looked at further stretches in 1996 the 500-700X variants but these kept the same basic outline

Boeing announced the 747-500X and -600X at the 1996 Farnborough Airshow.[77] The proposed models would have combined the 747's fuselage with a new 251 ft (77 m) span wing derived from the 777. Other changes included adding more powerful engines and increasing the number of tires from two to four on the nose landing gear and from 16 to 20 on the main landing gear.[159]

The 747-500X concept featured an 18 ft (5.5 m) stretch to 250 ft (76.2 m) long, and the aircraft was to carry 462 passengers over a range up to 8,700 nautical miles (10,000 mi, 16,100 km), with a gross weight of over 1.0 Mlb (450 Mg).[159] The 747-600X concept featured a greater stretch to 279 ft (85 m) with seating for 548 passengers, a range of up to 7,700 nmi (8,900 mi, 14,300 km), and a gross weight of 1.2 Mlb (540 Mg).[159] A third study concept, the 747-700X, would have combined the wing of the 747-600X with a widened fuselage, allowing it to carry 650 passengers over the same range as a 747-400.[77] The cost of the changes from previous 747 models, in particular the new wing for the 747-500X and -600X, was estimated to be more than $5 billion.[77] Boeing was not able to attract enough interest to launch the aircraft.[78]
en.wikipedia.org...

In retrospect though, I wonder... what if there were a dual-decked airliner in use today in the USA? Would it reduce flight traffic and the delays at airports? Would it be cost-effective, i.e.: would the increase in fuel consumption due to the weight be more than enough to offset the reduction in flights between airports due to fewer planes flying?

And off the cuff- thank someone that MD did not push the DC-10 in the direction the drawing above indicated, what with the engine mounts failing and such.

Originally posted by abecedarian
In retrospect though, I wonder... what if there were a dual-decked airliner in use today in the USA? Would it reduce flight traffic and the delays at airports? Would it be cost-effective, i.e.: would the increase in fuel consumption due to the weight be more than enough to offset the reduction in flights between airports due to fewer planes flying?

The US airline market is actually a very poor example to base any speculation off of - its largely going point to point, with frequency becoming more desired than capacity (although hub routes will never disappear). For example, rather than have one or two 400 seat aircraft flying between New York and Washington DC twice a day (start of business day and end of business day), you now have twenty or so 50 - 100 seat aircraft doing the same route, because businessmen no longer want to spend all day at their destination.

Smaller aircraft can also be both retasked and replaced easier - you can move a regional aircraft around between potentially thousands of destinations, while a jumbo can realistically only services a few dozen economically.

What you want to put your large aircraft on is the 'long fat' routes - the destinations that will *always* remain hubs for traffic.

People who insist that airline traffic is going down either the 'hub and spoke' or the 'point to point' markets completely are deluding themselves - hubs are more often than not hubs for reasons other than simply linking up point traffic, that only became part of their job as more destinations opened up. People will still want to fly between New York and London, because they are large financial centers.

And off the cuff- thank someone that MD did not push the DC-10 in the direction the drawing above indicated, what with the engine mounts failing and such.

Its worth noting that the engine mount only failed because of bad maintenance techniques (you do *not* leave an engine supported overnight by a forklift truck....).

Could have happened to any airliner.

[edit on 17/12/2008 by RichardPrice]

reply to post by deltaboy



Man I am glad that S570 is fictional, what an ugly bird.

Non of the 747's grace and elegance at all...

IIRC the 747-8 will have new wings and engines similar to the 787's, thereby increasing it's fuel efficiency considerably.

It's already the fastest commercial jet now that Concorde is no more. ( )