Aircraft and spotter question

[TW1Kell]

Are all aircraft capable of being spotters, or is there an ability listed for specific aircraft granting that ability? The other question made me wonder.

[Y2UAsk]

US aircraft can act as spotters for only one unit in the game -- the US 81 mm mortar. That's because the mortar has Improved Indirect Fire. Any US unit can spot for it, including US aircraft.

Steve