Design challenge: next generation heavy-lift cargo plane?

[riggerrob]

A few musings from a non-technical chap.

The main current user of heavy lifters is the USAF. Western countries (UK, Australia) tend to buy what the USAF buys.

The C17 is out of production but its configuration seems likely to influence a replacement (and the C5 replacement).

A high wing, four engined aircraft about the same length and wingspan would make infrastructure easier.

So within those limits we could see a wider fuselage with higher ceiling mated to more powerful engines and rugged undercarriage.
T tails seem to work but a single or twin fin need not be excluded.

The USAF could just opt to give C17/C5 the B52 Trigger's Broom treatment and keep rebuilding.

The civil lifter market is going to have A380s etc to play with.

Please note that under the current president, the USA is entering an isolationist phase, so is unlikely to spend much money on long-range transports.
Global logistics is shifting to large civilian corporations.

Finally, if you are going to steal parts from A380s - as they retire - then how about a tandem wing using all of the wings robbed from a pair of retiring A380s. Using a total of 4 wings and 8 engines will allow you to double gross weight and the tandem wings will be more forgiving of poorly-balanced loads.
Mount the wings on top of the fuselage to ease loading.
The long cargo compartment will allow mounting plenty of low-pressure tires to reduce point-loadings on asphalt runways. Perhaps mount 2 sets of nosewheels under the front edge of the fuselage side-walls.

 

[OliverSedlacek]

The oil industry is a big heavy lift user but they all use Antonov 124s. Airport infrastructure then constrains you to stick with that class of wingspan as it determines runway width, taxi way width, stand spacing and turning circles. There's not much demand for larger cargo volumes because when you break down plant equipment into transportable chunks you don't really want to exclude the 124 as your transport option. Weight might be a different matter.
Where does that leave you? Folding wings a la 777 Max? A possibility. A seaplane like the Hughes H4 'spruce goose'? I don't think so.

 

[Scott Kenny]

The oil industry is a big heavy lift user but they all use Antonov 124s. Airport infrastructure then constrains you to stick with that class of wingspan as it determines runway width, taxi way width, stand spacing and turning circles. There's not much demand for larger cargo volumes because when you break down plant equipment into transportable chunks you don't really want to exclude the 124 as your transport option. Weight might be a different matter.
Where does that leave you? Folding wings a la 777 Max? A possibility. A seaplane like the Hughes H4 'spruce goose'? I don't think so.

Right, which is why I suspect that the next big civilian cargo lifter will be An124 cargo bay dimensions, and funded by the oil industry. Probably have better engines, whether Jets or UDFs or turboprops.

I don't see a seaplane working for super-heavy-lift. I could see one working like the Beriev Altair as a passenger plane or convertible passenger+cargo plane to tropical islands and as a heavy fire bomber.

 

[Archibald]

A380-800F was to carry 160 tons while staying inside airports size constraints :
80 m X 80 m.
An optimized cargo plane fitting the same "box" but with 4xGE90s should be able to lift 180 to 200 tons.

 

[Grey Havoc]

I don't see a seaplane working for super-heavy-lift.

You might be surprised:

Shin Meiwa Industries' “GS"
(h/t Stargazer and Silencer1)

There was also an interesting French cargo jet seaplane, project, albeit a WIG design IIRC, from around the turn of the century, if I can ever find it again!

 

[Grey Havoc]

A sea skimming project from 2016 that I have just come across which you might be interested in, though this one was designed to serve short routes:

Enough With Going Supersonic—How About a Sea-Skimming Hybrid Cargo Plane?

The Pelagor is a concept ground effect seaplane designed to haul cargo short distances.

www.wired.com