Recon question

[MTTODD]

What determines if a recon plane will reveal the enemy unit in a hex ?

My recon plane flew on top of a city but did not reveal the enemy infantry unit in the city.

Many thanks.

[Myrddraal]

Infantry have the 'concealable' trait (you'll see it if you select one of your own infantry units on the right hand side of the stats bar).

The concealable trait means that infantry in forest or in cities won't be revealed unless there is a ground unit adjacent to them.

[MTTODD]

Thanks for your quick helpful reply.