BA Boeing 747-436 options in 1/72 and 1/144?

[71chally]

It does depend on how hung up on super accuracy one is, and then balancing what you see in a particular scale. 

Just for info, from FlightGlobal,

 

Aside from the stretch, there is little visual difference between the -8 fuselage and earlier marks. But the same is not true for the wing.

"The wing is key to this airplane, combined with the GEnx engines, and what makes it so dramatically different from its predecessors," says Dickinson. "There's the advanced technology airfoil with the supercritical wing and raked wingtip designed using computational fluid dynamics, giving it the same technology level as the 787 wing. It is extremely efficient."

The wing shares little with the 747-400 other than its 35˚ sweep and incorporates new materials that help reduce weight. The design features an optimised reloft and retwist, while the raked tip (in place of the winglet on the -400) increases wing span by 4m to 68.4m. "The new wing has similar dimensions to the earlier wing, but it is quite different. We really did not use any of the earlier aerodynamic features," says Dickinson. Although he declines to reveal the area of the new wing for competitive reasons, Lufthansa quotes a figure of 554m².

The wing incorporates revised leading and trailing edge high-lift devices while fly-by-wire outboard ailerons "enable the wing to be even more efficient with the weight reduction, by providing manoeuvre load alleviation, which is new for the 747. This gives us a significant advantage for weight."

The ailerons are optimised to span-load in cruise flight and Boeing has introduced a droop capability as a performance improvement. "We developed this initially on the Intercontinental and have since introduced it on the Freighter," says Dickinson.

"We realised during -8I flight-testing that we had the opportunity to better position the aileron to optimise span-loading and discovered a 0.4% improvement, which is a pretty significant number."

WING CHANGES

The wing's major changes centre on the flaps. "Optimising the trailing edge is a real opportunity for performance," says Dickinson.

All earlier marks (except the 747SP "shrink") incorporate triple-slotted trailing-edge flaps, but the -8 has adopted a double-slotted inboard and single-slotted outboard design, which extend on redesigned tracks and new carriages. The leading-edge variable camber Krueger flaps have also been redesigned to incorporate a gapped configuration. Actuation systems are unchanged. The spoilers are also now fly-by-wire.

Boeing spent a lot of time during flight-testing optimising the flap settings to improve on the approach speeds, which is "always a challenge, but we did this successfully". Dickinson says that "fundamentally, the wing's structural design is not entirely different" from earlier variants, although advanced aluminium alloys are incorporated in the wing and carbon composites are used for the trailing edge and raked tip.

During development, the changes to the 747 airfoil design created a variety of new problems. Speaking at the time, the programme's then chief engineer Michael Teal explained: "When we changed the wing airfoil and ultimately changed the centre of gravity, it fundamentally shifted how the whole aircraft balances loads. As the loads shifted back on the wing, the tail is the balancing load. So we changed more parts in the tail. Then the loads in the aft body changed, so we had to change the aft body."

The knock-on effect was that the 747-8 supply chain was thrust into limbo as it waited to adjust tooling and this contributed to the two-year programme delay.

"After we put that issue behind us, no follow-up was required since I joined the programme," says Dickinson.

The wing side-of-body has the same basic overall geometry and construct to the -400, but "has been 'gauged up' to account for the increased loads on the 747-8", Dickinson says. "The fairings are unchanged in basic geometry. 

 

 

[71chally]

Also worth noting that the fuselage was stretched the same overall length for -8I and -8F, but in different places, in modelling terms it makes little difference.  

The Revell -8F kit would be a good candidate for conversion to early short upper deck versions.

 

It's such a great kit and really well priced, along with the Zvezda kit, it really makes sense to use it as the base kit, possibly less work than correcting the old 400 kit.

 

 

 

 

Edited October 9, 2020 by 71chally

[skippiebg]

13 minutes ago, 71chally said:

It does depend on how hung up on super accuracy one is, and then balancing what you see in a particular scale. 

 

I stand corrected! I was wrong on the span, definitely. Still, the other changes are visually minor, however great they are in service. Thanks once again

 

--

 

PS FlightGlobal's online archive has now disappeared, very sadly...

[skippiebg]

Just to add that Eastern Express are definitely going to launch 747-100/200 and 400 kits in 1/144. How long that takes is another matter -- most likely not before 2022 and 2023-4. Their 747SP is about to hit the shelves. Cost is likely to be excessive, sadly...

[71chally]

I saw that their -100 was announced with box PanAm boxart recently.  I was unaware of a -400 release so that is great news.

There was an injected 72nd 747 planned by an unnamed manufacturer but has gone very quiet on that.

[WV908]

31 minutes ago, 71chally said:

Also worth noting that the fuselage was stretched the same overall length for -8I and -8F, but in different places, in modelling terms it makes little difference.  

The Revell -8F kit would be a good candidate for conversion to early short upper deck versions.

 

It's such a great kit and really well priced, along with the Zvezda kit, it really makes sense to use it as the base kit, possibly less work than correcting the old 400 kit.

 

 

 

 

Hi 71chally,

  Reading up on the old -400 kit the wings are too fat as well as sitting at the wrong angle, so I'd be better off with a -8 wing shapewise anyway 

 

Cheers,

  WV908

[71chally]

7 minutes ago, WV908 said:

 

 Reading up on the old -400 kit the wings are too fat as well as sitting at the wrong angle, so I'd be better off with a -8 wing shapewise anyway 

Comes to something when a different version is more accurate than the original!  That Revell Landor sells for around £50 now, crazy price.  You can get two of the lovely -8 kits for that.

 

Can I ask where you found the wing tips/winglets and flap fairings?  I hadn't realised that there were any available?

There is a lovely resin wheel set for -400s by Reskit, though it bumps the price up a bit.

[WV908]

@71chally The winglets and flap fairings are spares from Abandoned project, who is kindly supplying some RB-211's for my build in exchange for the -8 kit's engines

 

 

I'm not too bothered by different wheels in 1/144 so I'll not worry about those, but thanks for the heads up. 

 

Cheers,

  WV908

[71chally]

The -8 kit wheels are nice anyway, and certainly near enough for scale.

[Abandoned Project]

Very interesting technical details there. The -8i is definitely a better kit. Unless someone is aware of the subtle differences between the -400 and the -8 wing when looking at your model they won't get noticed.

[Cyberduck]

Hannants has a set of Boeing 707-336/-446 British Airways/Cargo and British Airtours. All registrations, Red tail Union flag scheme. Includes doors, windows and detail decals and British Airways Landor Boeing 747-436 "BA 100" decals in 1:144 scale for sale from 26 Decals for £10.80 and £12.00 each

[WV908]

Hi @Cyberduck It's the set that Hannants doesn't have that I need. It's the Negus 436 decals that I need and 26 decals will have it back in stock in four weeks, but thanks anyway

 

Cheers,

  WV908

[Abandoned Project]

This thread is very good for either option to build a 747-400

https://www.airlinercafe.com/forums.php?m=posts&q=10468

Especially post #68941 by Stevej for converting a -8i into a -400. It has a great set of step by step pictures.

[Turbofan]

Hi,

Just to add my thoughts and experiences.

I have done the Zvezda 747-8 to -200, -300 and am currently working on a -400 conversion and can recommend it to anyone. It isn't a particularly difficult conversion and most of what needs to be done is covered in this thread and on the Airlinercafe link above but there are a few extra things to be aware of.

 

Firstly, the trailing edge is different on the -8 being gently curved in the area of the high speed aileron. Fortunately this is easy to change as it seems to be a radius they have added to the old wing so therefore just needs to be removed but then the underside needs to be thinned out. 

This view shows the -8 wing trailing edge nicely.

http://cdn.cnn.com/cnnnext/dam/assets/130412144531-lufthansa747-8-wing.jpg

And this of the -400 from a very similar viewpoint

https://www.airliners.net/photo/Korean-Air/Boeing-747-4B5/5301421?qsp=eJwljUEKwjAQRe/y1xUiLRa6Uw%2BgCy8QkqEtVidMBjSU3t1p3D3eh/dXBH4rffVREmFAJi9hQoPkxb8yhhVPKh%2BWaIy%2B6w%2Bdc/s8sfLVK40sBUPrGmQWvRgjmj6HQEkp4u9vEkn2iXKo8dHOjgYk98poT%2BbjnNPia4PUzwu27QfdIjRz

 

Secondly, the leading edge of the vertical stabilizer is different for earlier 747s. See this thread.

https://www.airlinercafe.com/forums.php?m=posts&q=11378

 

Thirdly, the -8 does not have the 3 louvred vents on the underside of the WBF so these need to be either scratch built or represented with decals.

 

For me the different airfoils are not noticeable neither is the size of the wheels.

 

I believe converting the -8 to any of the earlier models, especially the -400 is the only way to get an accurate 747 unless you buy the Authentic Airliners kits but if you want as many 747s as me you'd need another mortgage to go down that route!

 

Hope this helps,

Cheers,

Ian

Edited October 10, 2020 by Turbofan

[Turbofan]

On 08/10/2020 at 19:04, Abandoned Project said:

On 08/10/2020 at 13:35, WV908 said:

Now to find the engines

I have a set of spare Revell engines if they are of any use.

Hi,

A heads up about the Revell RR engines, the intake trunking could do with thickening up as it is a bit thin and flimsy looking.

I have just lined the inside of the intake of mine with some rolled up .75mm plasticard and reshaped the intake rings with a rub round with some wet and dry and I think it's made the world of a difference.

Cheers,

Ian

[WV908]

Hi @Turbofan Thankyou for the extra information and links - it's good to have more evidence to back up and show the merits of the conversion. I have a Zvedza -8 kit on the way now and will either build G-CIVB in Negus 100 livery or G-CIVL in her 'One World' livery.

 

Cheers,

  WV908

[Abandoned Project]

A couple of pics of the wing trailing edge

As you can see the change is minimal