I noticed that some Mig-29 Fighter Jets have a little mirror-like-thing over the cockpit. I can't imagine a possible usage from it (If it's really a mirror).
Here's a picture from Wikipedia:
As you can see on the following picture, not every Mig-29 has this thing:
- What is this "Mirror"-like-thing supposed to do?
- Why can't I find it on every Mig-29?
- When is this thing used? In combat, training etc.?
- How does it help the pilot / trainer in flight?