Instrument rating · ACS IR.VI.A · lesson pack

Non-precision Approach

Why this one matters

Non-precision approaches have no vertical guidance, so the pilot manages the descent. Diving below the MDA early, or "ducking under" for a peek at the runway, puts the airplane below protected obstacle clearance in poor visibility, a classic pattern in controlled flight into terrain. Discipline at the MDA, a stabilized descent and an early decision prevent it.

1 · Know these cold

•A non-precision approach gives lateral guidance only, to a minimum descent altitude (MDA). You level off at the MDA and stay there until you see the runway environment or reach the missed approach point.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches)
•LNAV is GPS lateral guidance, linear ±0.3 nm on final. LP needs WAAS, uses angular scaling like a localizer, often has a lower MDA, and is published only where it beats LNAV. Neither is a precision approach: both use an MDA. An advisory glidepath (LNAV+V) does not change the MDA.(AIM, Chapter 1 (navigation aids, GPS and WAAS))
•You may not descend below the MDA unless you can land at a normal rate with normal maneuvers, have the required flight visibility, and see a required visual reference for the runway.(14 CFR 91.175)
•Don’t leave the MDA before the visual descent point (VDP), when one is published (straight-in only, based on the lowest MDA), and only with the 91.175(c) references. With none published, estimate it: height above touchdown ÷ 300 = miles from the threshold. If you pass the VDP still level and only then see the runway, a normal descent is no longer possible: go missed, don't dive.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches; 14 CFR 91.175)
•Tune, identify and confirm the navaid; for GPS, confirm the approach mode annunciates (for example LNAV or LP) before the FAF.(AIM, Chapter 1 (navigation aids, GPS and WAAS))
•Adjust minimums: your approach category; the Inoperative Components or Visual Aids Table (mostly visibility increases; with several components out, apply only the single largest); chart notes and NOTAMs that raise the MDA; and a remote altimeter setting (use the charted source, add the charted increment to every DA and MDA, apply any visibility increase, and no baro-VNAV or VDP where the chart says so).(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches; Terminal Procedures Publication)
•Checkride standard on final: no more than 3/4-scale deflection, airspeed ±10 knots, MDA +100/-0 feet to the VDP or MAP.(Instrument Rating ACS (FAA-S-ACS-8C), IR.VI.A.S12)

2 · The lesson

The approaches and their guidance

Ground-based non-precision approaches include VOR, localizer and NDB. Satellite-based: RNAV (GPS) LNAV and LP minimums.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches)
LNAV: GPS lateral guidance with integrity. LP: WAAS lateral guidance with localizer-like precision, used where vertical guidance can’t be published. Both have an MDA.(AIM, Chapter 1 (navigation aids, GPS and WAAS))
GPS habits: load the approach by name from the database, verify the waypoints against the chart, and check the RAIM prediction. The receiver arms approach mode within 30 nm of the airport and changes to approach sensitivity by 2 nm before the final approach waypoint (FAWP).(AIM, Chapter 1 (navigation aids, GPS and WAAS))
If it doesn't sequence to approach mode, or an integrity alert appears, before the FAWP: don't descend to the MDA; fly via the FAWP to the missed approach waypoint (MAWP), go missed there, and tell ATC. After the FAWP: start the missed immediately, flying to the MAWP before any turn unless ATC directs otherwise.(AIM, Chapter 1 (navigation aids, GPS and WAAS))
Identify the missed approach point: on RNAV, the MAWP; on ground-based approaches, a DME distance, a fix or intersection, station passage, or timing from the FAF using the chart's table and your groundspeed.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches)
Step-down fixes on any non-precision approach are floors: brief each one and how you'll identify it (DME or along-track distance), and don't descend below it until past it.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches)
Some GPS units show an advisory glidepath (LNAV+V). It’s advisory: the MDA and step-down fixes still govern.(AIM, Chapter 1 (navigation aids, GPS and WAAS))

Stabilized descent and energy

Two techniques. A continuous descent final approach (CDFA) flies a constant angle or rate from the FAF to a derived decision altitude (often MDA + 50 feet, so the missed starts without dipping below the MDA) and goes missed there if not visual. Dive-and-drive descends early to the MDA and levels off, with a long low segment. CDFA is the recommended one.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches; AC 120-108)
Know your descent rate: about 5 times your groundspeed in feet per minute gives a 3° path.(Instrument Flying Handbook (FAA-H-8083-15B))
High descent rates close to the ground, or large corrections, mean an unstable approach: go missed.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches)

At the MDA

Below the MDA only with: the airplane continuously in position to land at a normal rate with normal maneuvers, the required flight visibility, and one of the runway references in 91.175 (such as the threshold, runway lights, markings, REIL or VASI).(14 CFR 91.175)
The approach-light rule is two steps. (1) With the approach lights as your only reference, you may descend no lower than 100 feet above the touchdown zone elevation (TDZE). (2) If the red terminating bars or red side-row bars are also distinctly visible and identifiable, the approach lights let you go below 100 feet. Work the number out from the chart before the approach: TDZE plus 100 feet is your floor on the altimeter.(14 CFR 91.175)
Which lights have red bars: ALSF-1 has red terminating bars; ALSF-2 has red side-row bars in the inner 1,000 feet. MALSR, MALS and ODALS have none, so on those lights alone you never go below TDZE + 100; you need another listed reference (threshold, REIL, VASI, touchdown zone, runway, or their markings or lights) by then, or you go missed.(14 CFR 91.175; AIM, Chapter 2 (approach and runway lighting))
The lights never cure the other conditions: all three in 91.175(c) must hold the whole way down: continuously in position for a normal descent with normal maneuvers, the required flight visibility, and a listed reference distinctly visible and identifiable, not just glimpsed. And 100 feet above TDZE is a floor on a continuous descent, not a place to level off. Leave the MDA toward it only if a normal descent to landing is possible from where you are; reach it without a qualifying reference and you go missed right then.(14 CFR 91.175)
If the references aren’t there at the MAP, go missed immediately.(AIM, Chapter 5, Section 4 (arrival and approach procedures))

Flying it: setup, automation and configuration

Brief the chart before you need it: frequencies, final approach course, FAF altitude, minimums, the missed approach, and notes.(Instrument Procedures Handbook (FAA-H-8083-16B), Approaches)
Tune, identify (Morse code) and confirm every navaid; for GPS, check the approach is loaded and the correct mode annunciates before the FAF.(AIM, Chapter 1 (navigation aids, GPS and WAAS))
Know what the autopilot and navigator will do next, and be ready to hand-fly. Automation confusion on an approach is a known accident pattern.(Risk Management Handbook (FAA-H-8083-2A))
Configure in stages, per the POH: approach configuration and speed by the FAF so the final segment needs only small changes; final flaps when landing is assured (when circling, not until you leave the MDA). Know the missed approach configuration too.(Your airplane's POH/AFM)
Fly the procedure as published or as cleared. If you can’t comply with a clearance, say "unable".(AIM, Chapter 5, Section 4 (arrival and approach procedures))

Want it all on one page, with scenarios? Read the full lesson.

On the flight

ACS standards

Before the final approach segment: altitude ±100 feet, heading ±10°, airspeed ±10 knots, no more than 3/4-scale CDI deflection.(Instrument Rating ACS (FAA-S-ACS-8C), IR.VI.A.S9)
On final: no more than 3/4-scale CDI deflection, airspeed ±10 knots, and altitude above MDA +100/-0 feet to the VDP or MAP.(Instrument Rating ACS (FAA-S-ACS-8C), IR.VI.A.S12)

What your instructor is watching for

Your instructor watches your briefing, navaid identification and GPS mode check, a stabilized descent to the MDA, holding the MDA precisely, and a prompt missed approach without the required references.

3 · Say it out loud

Answer each one out loud, then check yourself and mark how it went.

Remember Recall it
“What’s the difference between LNAV and LP?”
Understand Explain why
“Why not leave the MDA before the VDP?”
Apply Use it on a flight
“At the MDA you see the approach lights but not the runway. How low can you go?”

4 · Common mistakes

Diving and driving without a plan.
Long level segments at low altitude, and late, steep descents.
Instead: Fly a CDFA to a derived decision altitude, or brief the step-downs and VDP if you must level off.
Ducking below the MDA early.
No obstacle protection without the references.
Instead: Stay at the MDA until you meet 91.175.
Skipping the GPS mode check.
Wrong sensitivity or integrity.
Instead: Confirm the approach mode before the FAF.

5 · Quick check

Answer, then reveal. Flag anything you want to see again.

1. What minimum does a non-precision approach use?
2. Name three requirements to descend below the MDA.
3. Does an advisory glidepath (LNAV+V) change the minimums?
4. What is a VDP?
5. Checkride altitude tolerance on final?
Scenario6. A RAIM/integrity alert appears after the FAF. What do you do?

Trained it? Now prove it: practice non-precision approach out loud with our examiner.

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Connect it

One situation that runs across this lesson and its neighbors in the same ACS area. Decide first, then check.

Connect it · Instrument Approach Procedures

On an LNAV approach you reach MDA two miles before the missed approach point. At one mile you see approach lights, but not the runway.

Can you descend, how far, and what makes you go missed? Decide, then see the worked answer

Under 91.175(c) you may leave MDA only when the airplane is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers, the flight visibility is at least the published minimum, and at least one of the listed visual references for that runway is distinctly visible and identifiable. The approach light system counts, but it lets you descend only to 100 feet above the touchdown zone elevation. That's a floor for the descent, not a target to level off at. Below it you need the red terminating bars or red side row bars, which only ALSF-1 and ALSF-2 systems have, or another 91.175(c)(3) reference: the threshold, its markings or lights, the REIL, the VASI or PAPI, the touchdown zone, or the runway, its markings or lights, distinctly visible and identifiable. Reach 100 feet without one and go missed immediately. Go missed at the MAP if you don't have the references. If you lose them below MDA, go missed at once too. Obstacle clearance on the missed approach assumes it starts at or above MDA at the MAP, so climb, re-intercept the published missed approach as safely as you can, and contact ATC as soon as possible.

14 CFR 91.175(c)-(e); AIM 5-4-21

Brings together: Non-precision Approach · Missed Approach · Landing from an Instrument Approach

Teaching this? The instructor lesson plan →

Study aid, not FAA guidance. Sources: Instrument Procedures Handbook (FAA-H-8083-16B); Instrument Flying Handbook (FAA-H-8083-15B); Aeronautical Information Manual (AIM); 14 CFR; Instrument Rating ACS (FAA-S-ACS-8C); Terminal Procedures Publication (TPP). Checked against current sources 2026-11-13.