I just noticed this as of Heart of the Swarm Patch 2.02- Flying units like mutalisks have a 'turning radius' when they are making a turn less than about 170 degrees, but when they are turning almost perfectly 180 degrees, they do a perfect 180 and do not lose momentum.
I made a quick video of a mutalisk using this in combination with attack-move to appear to shoot while turning, reminiscent of BW mutalisk micro. This may be the standard for WoL, but as I couldn't find any mutalisk micro threads I thought I'd share!
![](https://s2.save4k.ru/pic/ITep_eK4t8Y/mqdefault.jpg)