How to float an instantiated spaceship from up to down?

I’m making a game like spaceshooter, warplanes come from upside and I’m trying to shoot them before they get borderline.

I’ve set a startpoint above and instantiate enemyplanes one by one as below code

enemyPlane = (Rigidbody)Instantiate (enemyPlane, startPoint, enemyPlane.rotation);

normal rotation of enemies should be uptodown (as seen right) 25864-11.png

but they fly as if they look from left. How do I set them as seen on picture?

Maybe you need to correct rotation before instantiate?

Quaternion rot = Quaternion.Euler(0, 0, 90.0f);
enemyPlane = Instantiate(enemyPlane, startPoint, rot)