Non-Precision Approach

FAA-S-ACS-8 defines a non-precision approach as a standard instrument approach procedure to a published minimum descent altitude without approved vertical guidance, and adds that the applicant may use navigation systems that display advisory vertical guidance during a non-precision approach if one is available. Advisory guidance does not change the classification — the approach is still flown to an MDA, and the MDA is a hard floor rather than a decision point.

The tolerances mirror the precision approach up to the final approach segment: altitude ±100 feet, selected heading ±10°, airspeed ±10 knots, no more than ¾-scale CDI deflection, and accurate tracking of radials, courses or bearings. The final segment is where the difference shows. The applicant maintains no more than ¾-scale CDI deflection and airspeed ±10 knots, and where altitude applies, holds it above the MDA at +100/−0 feet to the visual descent point or missed approach point. The asymmetry in that tolerance is the whole point: 100 feet high is a deviation, and any amount low is a bust, because the MDA is a minimum.

The checkride composition is prescriptive. The evaluator must select and the applicant must accomplish at least two different non-precision approaches. At least one must include a course reversal manoeuvre — a procedure turn, holding in lieu, or the course reversal from an initial approach fix on a terminal arrival. At least one must be flown from an initial approach fix without the autopilot and without radar vectors, though the yaw damper and flight director may still be used. And one must be flown with reference to backup or partial-panel instrumentation representing a realistic failure mode for the equipment installed.

Non-precision approaches are where instrument students spend most of their workload budget, and where the greatest variety lives: LNAV, LP, localizer, VOR and NDB procedures all fall under the same heading but fly differently. FAA-S-ACS-8 singles out the distinction between Localizer Performance and Lateral Navigation approach guidance as an explicit knowledge element, alongside the navigation system indications and annunciations expected during an RNAV approach — a recognition that in a modern cockpit the hardest part of a non-precision approach is often knowing what the box is doing.

The three-way composition requirement is a real planning constraint for a school. A course reversal, an autopilot-free approach from an initial approach fix, and a partial-panel approach cannot all be satisfied by flying the same procedure twice, so the instrument syllabus has to be built around what procedures are reachable from the school's base.

Aviatize lets a school model each required approach variant as a separate syllabus objective, so the course reversal, the initial-approach-fix approach without autopilot and the partial-panel approach are tracked individually rather than counted as generic approaches. A chief instructor reviewing a student for a checkride recommendation can see which variants are genuinely complete, and which have been logged but not yet flown to standard.