Wed Feb 06, 2019 1:10 pm
#1672319
Genghis the Engineer wrote:IFR traffic, of any size, uses much less airspace than VFR because it can be assumed to be able to stick to a height and track. Because VFR traffic must be able to stay clear of cloud, it cannot - hence "not above", "not below", "staying west of", etc.
That's one way to look at it. But the opposite argument is also valid.
IFR needs to be separated from other IFR by 1000ft or 3/5NM (depending ATSU) whereas VFR don't need to be separated. So IFR use much more airspace.
Controller and power VFR pilot should be able to come to a fixed level/track in most case if the weather conditions are not marginal.
Of course for gliders and for all when conditions are iffy we need "not above" and "west of".