'Counter-air': Air attacks on air bases

[Diplomaticus]

According to the manual,

13.3 Air to Air Combat
In Air to Air combat, both attacker and defender fire simultaneously; there is no Shock Phase.

So, in a standard dogfight, it's a level playing field.

I've been wondering, though, about the mechanics of air strikes on air bases. It seems clear that the defender gets an advantage:

(13.2 Fire Phase: After the Shock Phase is the Fire Phase. The defender fires first in the Fire Phase, using the appropriate combat attribute as specified in the Unit Attributes above. This is multiplied by the Combat Modifier to get a percent chance of each Strength Point in the unit hitting and killing an enemy Strength Point and reducing the unit’s Effectiveness. Once the defender has fired, the attacker gets a chance to attack back with any remaining Strength Points.)

But do air units being bombed/strafed by other air units benefit from terrain? Does, say, a fighter unit based in a city defend more effectively when strafed than it would on a plain hex?

TYIA for your advice on this point.

[firepowerjohan]

No terrain or trench effects are used in Air vs Air or Carrier vs Carrier or Air vs Carrier.