Precision Approach

The FAA's definition in FAA-S-ACS-8 is precise about what makes an approach a precision approach: it is a standard instrument approach procedure to a published decision altitude using provided approved vertical guidance. Two things distinguish it from a non-precision approach — the vertical guidance is approved rather than advisory, and the pilot flies to a decision altitude rather than descending to and levelling at a minimum descent altitude. At the DA the decision is binary and immediate: if the required visual references for the runway are not unmistakably visible and identifiable, the missed approach is initiated at once.

The skill tolerances split the approach into two phases. Before the final approach segment, the applicant maintains altitude ±100 feet, selected heading ±10°, airspeed ±10 knots, and no more than ¾-scale CDI deflection, while accurately tracking radials, courses or bearings. From the final approach fix to the DA or DH, the standard is a stabilized final approach allowing no more than ¾-scale deflection of either the vertical or the lateral guidance indications, with airspeed held within ±10 knots. The ACS notes that because instrument markings vary, ¾-scale deflection is deemed to occur when the indication is displaced three-quarters of the distance it can be deflected from the on-path indication.

The applicant also has to establish a predetermined rate of descent at the point where vertical guidance begins, approximating the rate required to follow that guidance, and to adjust the published DA or DH and the visibility criteria for the aircraft approach category to account for NOTAMs and for inoperative aircraft, navigation or visual-aid equipment.

For a school, the precision approach is the point in the instrument course where energy management stops being a talking point and becomes the grading criterion. The ACS lists a stabilized approach, including energy management concepts, as an explicit knowledge element, and an unstable approach including excessive descent rates as a risk-management element. A student who arrives at the final approach fix fast and high can still salvage a non-precision approach; on a precision approach the glidepath is unforgiving and the deviation shows up immediately.

The scheduling implication is that precision approaches need either a suitably equipped aircraft at an airport with the procedure, or a qualified flight simulation training device. Schools that run instrument courses at scale generally plan the device time and the aircraft time as a single sequence rather than booking them independently.

Aviatize records each approach type flown as its own syllabus objective, so a school can see at a glance which of the required approaches a student has completed and which are still outstanding before a checkride. Because aircraft, simulator and instructor availability all sit in the same schedule, a course coordinator planning an instrument block can see whether an approach-equipped aircraft and a qualified instructor are free in the same slot rather than discovering the conflict on the day.