What causes Fighters to not intercept bombers?

[AlbertN]

Start of the turn...
It seems fighters have not intercepted at all, and I do not know why. (Yes there is oil in stock).
Is it a bug or is there something I do not know of?

Also I feel there is some error in the formula of the Efficiency recovery. Or at least my math is not returning of how much efficiency troops are to recover.

[Worg64]

Problary their low effience value, they are hardly a fighting unit with those numbers.You need to rest them and get back to health

[AlbertN]

Don't think that's the case. If I do not want to have them intercept to have them rest I set them 'mission only'.
Otherwise they should intercept no matter what as long as they got fuel.