Non-precision Approaches

Everything tightens on final. Prior to the final approach segment: altitude ±100 feet, selected heading ±5°, airspeed ±10 knots, accurately tracking (AA.VI.D.S9). On the final approach segment: no more than ¼-scale CDI deflection, airspeed ±5 knots of the selected value, and altitude above MDA +50/−0 feet to the VDP or missed approach point (AA.VI.D.S12). Compare the instrument rating: ¾-scale, ±10 knots, MDA +100/−0. A third the lateral corridor, half the speed band, half the altitude window — flown in an airplane covering the final segment roughly twice as fast.

A ¼-scale deflection means the indication is displaced ¼ of the distance it may be deflected from the on-path indication (ACS Appendix 3, Vertical or Lateral Deviation Standard) — instrument markings vary, so the ACS defines it explicitly. On a five-dot display that's about one dot from center; on a two-dot display, half a dot. Know what a quarter of your scale looks like before the check, because the evaluator does.

At least two different non-precision approaches in simulated or actual IMC:

• At least one including a course reversal (procedure turn, hold-in-lieu, or the course reversal from an IAF on a Terminal Arrival Area (TAA))
• At least one from an IAF, without the autopilot and without radar vectors — the yaw damper and flight director are allowed
• One flown with backup or partial panel instrumentation or navigation display, representing a realistic failure mode for your avionics

Advisory vertical guidance may be used, and the evaluator decides whether each approach ends in a landing or a miss (ACS Appendix 3).

A DDA (derived decision altitude) is the altitude above the MDA where the go-around must begin, ensuring the airplane doesn't sink below the published MDA during the missed-approach transition (AC 120-108 para 3.7, citing 91.175) — necessary because pilots must not descend below the MDA once executing a miss. At the DDA there are exactly two courses of action: continue visually with the 91.175 references in sight, or execute the missed approach without descending below the MDA, proceeding on track to the MAP before any turn (AC 120-108 para 3.8.1). The +50/−0-foot skill tolerance (S12) is this discipline in miniature: the bottom of the window is hard.

Continuous descent final approach: a constant-rate, constant-angle descent from the FAF, timed to intersect the MDA near the point a normal landing descent continues to the runway — instead of dive-and-drive level-offs. It's built on the stabilized-approach concept: for turbojets, before descending below 1,000 feet above the airport or TDZE on any straight-in instrument approach —

• Approved landing (or circling) configuration
• Engines spooled up
• On speed and flight path
• Descent rate less than 1,000 fpm

(IPH ch. 4). The ACS folds the same components into its own definition — stable speed, stable descent rate, stable vertical path, and departure from the FAF configured for landing (ACS Appendix 3, Stabilized Approach Criteria). Cross the FAF at final approach speed, configured — especially on timing-dependent approaches (AC 120-108 para 3.6).

From the DDA:

1. Do not descend below the MDA
2. Unless ATC has issued climbout instructions, fly the published missed approach procedure
3. Proceed on track to the MAP before accomplishing any turn (AC 120-108 para 3.9)

The published miss provides obstacle clearance only from the missed approach segment at or above the MAP, assuming a climb of 200 ft/NM or higher as published (IPH ch. 4). Turning early trades protected airspace for hope.

What changes is the tolerance interaction: LP's sensitivity increases as you approach the runway, so the same ¼-scale standard demands progressively smaller corrections, exactly like a localizer. The definitions themselves don't change from the instrument rating — LNAV is linear-scaled lateral GPS guidance; LP uses WAAS for localizer-like angular guidance, published where terrain or obstacles preclude a vertically guided line — both flown to an MDA (covered in the IFR guide, Task VI.A). Know your navigator's annunciations cold (K2): the ACS expects you to recognize inaccurate or inoperative instrumentation and act (S5), and a mode that never activates is a mandatory miss, not a judgment call.

Select, tune, identify, and confirm the operational status of the navigation equipment to be used for the approach (AA.VI.D.S3). The risk the ACS names is selecting the wrong navigation frequency (R2) — classic setups: the localizer or VOR for a parallel or nearby procedure, the ILS tuned when the clearance is the VOR, or a CDI still showing GPS while the briefed needle is a localizer.

Defenses:

• Identify the facility (Morse ident or the navigator's decoded ident)
• Verify the loaded procedure's fixes against the chart
• Confirm the nav source annunciation on the display that's actually flying the approach

Signal-integrity and interference fundamentals (K3) are unchanged from the instrument rating — covered in the IFR guide; the ATP behavior is confirming status before the approach and acting on a loss-of-integrity annunciation when it appears (K2, S5).

Work the chart against reality:

• NOTAMs — procedure NOTAMs can raise minimums or make lines of minima unusable
• Inoperative aircraft or navigation equipment — losing a sensor may drop you to a higher line of minima
• Inoperative visual aids — apply the TPP's Inoperative Components Table; the IFH example: an ILS with a malfunctioning MALSR can be flown if minimum visibility is increased by ¼ mile — and watch for chart notes like "Inoperative Table does not apply to ALS" (IFH ch. 1)
• Aircraft approach category — flying final faster than your category's band means the higher category minimums apply (IPH ch. 4)

Under part 121 there's a gate before any of that matters: you may not continue past the FAF unless a weather report exists and reports visibility at or above the procedure's minimums (121.651(b)) — details under the precision task.

Unstable: any stabilized-approach component missing below the gate —

• Configuration not final
• Speed off target
• Descent rate excessive — greater than about 1,000 fpm below 1,000 feet is unacceptable in either the instrument or visual portion, a human-perception limit (IPH ch. 4)
• Flight path not established

Response: a go-around, decided by criteria, not by feel. The ACS treats attempting to salvage as the risk; the skill it wants is a stabilized descent to the appropriate altitude (S11) and a prompt miss when the picture isn't right (S13).

Plan to arrive at the DDA decision, not at a level-off. If the operator's CDFA procedure has you go missed at the DDA, the window takes care of itself — the airplane never levels at the MDA. If you do level (for example, running to a VDP on a timing approach), lead the level-off consistent with your descent rate, trim, and keep the FD or pitch reference on the horizon line rather than chasing the altimeter. The tolerance runs to the VDP or MAP (AA.VI.D.S12) — brief which of those points ends your level segment and what happens there before the FAF.

Fly your operator's flow; the pattern the evaluator expects to hear (per the ACS's briefing and CRM threads, Appendix 3; AA.VI.D.S7):

• Approaching the FAF: configuration confirmed, final approach speed set, missed approach reviewed
• FAF: time started if applicable, descent rate called
• Through each stepdown: altitude verified against the chart by the monitoring pilot
• Approaching minimums / minimums: the decision callout — runway cues or go-around
• Any deviation beyond the operator's limits: called immediately, corrected or rejected

The ACS grades the underlying skills directly: checklist timing (S7), configuration and airspeed for conditions (S8), and MFD use to monitor position and wind drift (S14).

The requirement is calibrated to your airplane: backup or partial panel instrumentation or navigation display, depending on the aircraft's avionics configuration, representing a realistic failure mode (ACS Appendix 3). In a glass transport that usually means standby instruments or a reverted/composite display, not a covered vacuum gyro. The graded skill is recognizing what failed and acting (AA.VI.D.S5) — which display survives, which nav source still feeds it, and how the ¼-scale standard will be judged on the surviving needle. Rehearse the reversion in your type before the check; the failure the evaluator picks will be one your airplane can actually have.