That only left the question of how many and what type of planes they should make, which was going to be a much easier decision than upgrading a whole network of underground tunnels.
The twin-engine plane that they had now could carry half a tonne of gear anywhere in their territory, which was enough for a single village at a time or multiple if they only needed a limited selection of what they had to offer.
Since they had about ten villages on the eastern side of the Frozen Wastes to look after, that would be about fifty kilos each when divided between a plane.
That was plenty for basic munitions drops, but they would have to be frequent for the villagers to keep up if the Grand Dutchies started to become a real nuisance.
So it was either send one of them every few days or make a much larger aircraft.