Whilst researching for the logistics series I cam across this but didn’t include it.
The image below shows a system for double stacking 463L pallets and LD3 containers on the Japanese C2 transport aircraft.
It looks like an ingenious way of maxing out the volume of the cargo hold. Aircraft rarely max out on payload but with pallets, it is floor space that is the limiting factor, especially with low density payloads.
Although 463Lpallets can be double stacked there are restrictions.The rack system would add some weight but could be demountable and only used when required.
Interesting potential for the A400Mand C17 fleet.