From: Washington D.C.
In some scenarios, what I do is set up areas that the aircraft has to fly over. When it does this, it triggers an Event that says you have completed the recon mission and you get points. (You could cheat and use the aircraft without the recon loadout, but I'm not sure why anyone would do that.)
That's what I do with things like SR-71, old U-2 and RF-4 sorts of aircraft.
Of course, if what you're looking for is mobile units, then you actually have to fly around until you detect them. But, of course, you can use a Detect Unit trigger for the Event and give the player points that way. (And, of course, if the recon plane gets shot down, you lose points.)
I'm not so sure that'd be how you'd use an aircraft like that, though. That'd be more a job for a low-flying sort of aircraft like an OA-10, or an aircraft with a synthetic aperture radar like the JSTARs or newer U-2 variants. In that case they'd be looking specifically for moving targets using a MTI radar mode.