This is called a nonprecision approach
. Here, the pilots may be alone with a single nondirectional radio beacon, perhaps quite far from the field.
* For a nonprecision approach
procedure (LPV, LNAV, VOR, etc.): Ceiling 800 feet and visibility of two statute miles.
In other words, according to the AIM, "The presence of a VDA does not guarantee obstacle protection in the visual segment and does not change any of the requirements for flying a nonprecision approach
So, there was no nonprecision approach
that day into my home field, but there was a perfectly usable ILS available only 15 miles away.
If you fly a FAA Practical Test Standards-style, "dive and drive" nonprecision approach
(as opposed to the growing technique of flying a constant-rate, glideslope-like descent on nonprecision approaches
as well), you'll need a fourth configuration for flying in the draggy, level-flight condition at Minimum Descent Altitude.
CDFA Continuous Descent Final Approach: The opposite of the "dive-n-drive" method of flying a nonprecision approach
, CDFAs use a calculated descent rate from FAF to the runway.
Other important info at this stage is the final aproach course itself, the distance from the final approach fix to the runway and the decision height for an ILS or minimum descent altitude for a nonprecision approach
. Now's a good time to also get an idea of where the missed-approach fix is and what it'll take to get there.
The table below tells us if the approach is a NonPrecision Approach
(NPA) or precision (including APV).
Jeppesen uses a dashed line to depict the nonprecision approach
profile, showing a minimum altitude of 2560 until KNOLL and then a slight descent to the MDA at XOPYU.
In a nonprecision approach
(to an MDA), the path is clear to the MDA.
Change 2 permits an applicant to fly an LPV with a DA above 300 feet height above terrain (HAT) as a nonprecision approach
. An LPV with DA of 300 feet HAT or less can be used to demonstrate precision approach proficiency.
What constitutes a precision, versus nonprecision approach
? It was always my understanding, from the 2007 FAA Instrument Procedures handbook, that LPV approaches were considered nonprecision, despite the fact that they have similar performance capabilities as the ILS approach.