Quick Question

I'm playing Diety Babylon for a SV but one of my cities is being hit by air strikes, I have defending fighters set on intercept.
Now they are due for promotion, so question is do air units set to intercept heal each turn like fortify or do I need air repair for that.
If they heal by themselves each turn then am I better with Air Sortie (for 2 intercepts per turn) or Interception 3 for 100% bonus?
Basically I dont have the income stream to replace units every turn so I need to conserve my military as much as possible.
I guess having a medic unit will also heal air units?

Edit: 1 of the fighters is down to 50% so I need to ensure they stay alive.

Take Air repair. That'll keep them alive for a significantly longer time. This also stacks with faith healers if you have it, making your planes near invincible. Alternatively, Interception three so that they wont take nearly as much damage as intercepting. Not as effective, but it'll still get the job done. DO not take Air sortie though. Although it may take any craft down faster, that also means it'll wear YOUR craft down faster. The only thing it does for you is kamikaze itself into the other planes.

Thanks thats definitely the way to go