Initial approach fix
The Initial Approach Fix (IAF) is the point where the initial approach segment of an instrument approach begins. An instrument approach procedure may have more than one Initial approach fix and initial approach segment. The initial approach fix is usually a designated intersection, VOR, NDB, or DME fix. The initial approach fix may be collocated with the intermediate fix (IF) of the instrument approach and in such case they designate the beginning of the intermediate segment of the approach. When initial approach fix, and intermediate fix are combined there is no initial approach segment.