How come other helicopter light up bright white under night vision? Also the runway's are also way to bright.

Thermal/FLIR sensor fusion into the helmet display system. It's part of the Apache, Comanche, and Zulu stuff, so the rest of the American helos all have it too in the sim. In the config ini you can turn this off for the Russian aircraft, which is what I do. And yeah, it's not particularly subtle. I'm not sure if there's a way to do it for all aircraft in the sim, but considering the current issues with targeting by way of the FLIR MFD, you might want to keep it on.