Is spray paint okay for plastic plane models?

Yes, it's fine... though I always use Testors brand spray paint for models.

As another answerer stated... wash your model before painting with lukewarm water and a little dish soap. This will get rid of finger-oils and other stuff that can mar the finish.

You can prime or not... but DO follow the instructions on the can... make sure you shake well, hold can 8-10 inches back, and move the can smoothly. It's better to put on two light coats than one heavy coat that might run.

To get the BEST results with decals... paint with a gloss paint OR give a coat of gloss finish to a matte paint before decals. Decals always adhere best to a smooth glossy coat... decals over matte paint will often "silver" (show a strange silver look that is micro air-bubbles trapped in the "texture" of a matte paint. If you want a matte finish... spray with a matte-coat AFTER you've applied the decals.

My Uncle painted hundreds of WWII models including Airplanes: detailing down to the brass buttons on soldiers uniforms. Spray paint is not only safe to use but gives a better coating; without brushmarks. It can be used to great effect on the base colors of camoflage also. Painting the dark green basic in spray and later going over the other color patterns by brush. Just use light spray in layers rather than blasting it close up and heavy which produces runs and drips and also can fill in details and puddle in places you do not want it. But if you keep the can at least a foot away and spray lightly and quickly with thin coats; with sweeping back and forth motion to avoid overspray allow at least 15 min between coats. It will give a more professional look with a cleaner surface, and can get in places not easily accesed by brush.

If you get good spray paint ($6-7 a can) you'll be fine but the cheap stuff that like $2 will drip and will always rub off on your hands and decals will not still to that.

Spray paint will work but u need to do it properly.

Wash what your painting.

Prime it with Primer.

Paint it.

Use a lacquer to make it last and shiny.

U'll be able to find help on youtube etc.

I think it'd be fine.

I think it'd only be a problem if it was a Styrofoam model... spray paint would be too harsh and would make the material shrivel and look awful...

I don't consider that's accurate

That's not true

yes. its safe.