Can someone please tell me why the F-18E didnt explode completely in the movie Behind Enemy Lines. Instead it broke into two perfect pieces giving the pilots time to eject. Also, what kind of missile struck the plane. Im assuming that its not heat-seeking because it totally ignored the flares that were previously dropped by the aircraft.

I love that movie! As far as how realistic that ejection scene was  don't know, that was probably just Hollywood adding drama to the movie. Also, heat-seeking missiles are not always stopped by flares, I am pretty sure that that was a heat-seeking missile. If it had been a radar-guided missile then the pilot would have released chaff instead of flares.

I hope that helped.

It broke apart perfectly because that's simply how the Hollywood producers scripted it.  That was a good movie, but that scene was pretty unrealistic.