When I unlocked the Prydwen as a fast travel destination, I noticed it was flagged as a Settlement.

So, given that it was labelled as such, I tried to connect it to my network of supply caravans, both to ensure a steady supply of food and grant them access to my crafting resources.

Thus far, I have not figured out a way to do so.

Boston Airport is the nearest Settlement and it appears it cannot be developed in any meaningful way.

You can't build a Recruitment Beacon, which means no Settlers.

I sent one of the Castle Settlers to this settlement. but so far, they have not shown up there.

My theory was if I could get this Settler to arrive, I could then send them to the Prydwen as a supply caravan.

So given the fact that Prydwen can't be used as a real Settlement at all, why is it identified as one?

The best I could do was put a Power Armor Station in Boston Airport and connect it to my caravan network, since it appears Prydwen doesn't have the materials on hand to repair my Power Armor when it gets damaged.

You are allied with the BoS, so you have access to their settlements to a limited extent

At least that's how I think it works

Now I am very confused!

Somehow a supply line got established directly to the Prydwen:

http://steamcommunity.com/sharedfiles/filedetails/?id=565957514

How did this happen?

And somehow, it removed my supply link to the Airport in the process.

I'm not sure I can fix this, how can I upgrade the Airport at all without access to any of the materials in storage?

I just checked the Workshop, it's got very little in the way of construction materials.

The Prydwen and Boston airport are all considered 1 settlement.

Setting up a supply line to the airpost sets the line to the Prydwen since its all the same settlement in the end.