Question about the Semicircular Rule
So, I'm in the process of revising for my Air Law exam this weekend and I'm a little puzzled about the Semicircular Rule (IFR Rule 34).
I understand the basic principle that above FL245, the cruising level is determined by the aircraft's magnetic track. Simple.
What I don't understand is the levels which are stipulated for tracks 000-179 degrees: FL250, 270, 290, 330 (wait, what about 310?), 370 (no 350 either?)
And for tracks 180-359 degrees: FL260, 280, 310 (not 300?), 350, 390.
Although it'll probably never be of any concern to me in a PA-28, I'd just to satisfy my curiosity!
Rich