Non-precision Approach

A standard instrument approach procedure flown to a published minimum descent altitude (MDA) without approved vertical guidance (FAA-S-ACS-8C, Area VI). The lateral-only family: VOR, LOC, NDB, and the LNAV and LP lines of minima on RNAV (GPS) charts. You may use a navigator that displays advisory vertical guidance — but the approach is still flown to an MDA, honoring every stepdown altitude on the barometric altimeter (FAA-S-ACS-8C; IPH ch. 4).

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

• At least one must include a course reversal (procedure turn, hold-in-lieu, or a TAA course reversal)
• At least one must be flown from an initial approach fix (IAF) without the autopilot and without radar vectors (yaw damper and flight director are allowed)
• One must be flown with backup or partial panel instrumentation, representing a realistic failure mode

The evaluator decides whether each approach ends in a landing or a missed approach (FAA-S-ACS-8C, Area VI Task A).

Before the final approach segment: altitude ±100 ft, heading ±10°, airspeed ±10 knots, no more than ¾-scale CDI deflection (VI.A S9).

Final approach segment: no more than ¾-scale CDI deflection, airspeed ±10 knots, and MDA +100/−0 feet to the visual descent point (VDP) or missed approach point (MAP) (VI.A S12).

Both are non-precision lines flown to an MDA.

LNAV — basic GPS lateral guidance; CDI scaling is linear (±0.3 NM on the final segment).

LP — uses WAAS accuracy to give localizer-like angular guidance: lateral sensitivity increases as you near the runway. LP is published only where terrain or obstacles prevent a vertically guided line (no LPV or LNAV/VNAV on the same chart), it is not a fail-down mode for LPV, and your WAAS navigator must be specifically approved for LP in the AFM (AIM 5-4-5).

• Within 30 NM of the airport: CDI ramps from ±5 NM en route to ±1 NM terminal sensitivity — arm the approach no later than this point
• Within 2 NM of the final approach waypoint with the approach armed: approach mode goes active and CDI ramps smoothly to ±0.3 NM
• If the approach mode is not active before the FAWP, the equipment flags — do not descend to the MDA; fly to the missed approach waypoint and execute the miss (IFH ch. 9)

Depends on the procedure (IFH ch. 1; IPH ch. 4):

• Timing from the final approach fix (FAF) — start the clock at the Maltese cross and use the chart's groundspeed/time table (30-knot increments), based on your estimated groundspeed
• NAVAID passage, when the VOR or NDB sits on the field
• A fix — DME on the course, a cross radial, or an RNAV (GPS) waypoint

On the chart it's where the solid course line ends and the dotted missed approach track begins.

A defined point on the final approach course of a non-precision straight-in approach from which a stabilized visual descent from the MDA to the runway touchdown point may be begun — charted as a V in the profile view and identified by DME or RNAV along-track distance to the MAP. You should not descend below the MDA before the VDP, and if you can't identify the VDP, fly the approach as if none were published (AIM 5-4-5).

No. The VDA is advisory only — an aid to a continuous, stabilized descent to the MDA, not procedure-derived vertical guidance. It guarantees no obstacle protection below the MDA in the visual segment; where an obstacle penetration would force a deviation from the VDA between the MDA and touchdown, the angle isn't published — the chart carries the note "Visual Segment - Obstacles" instead. Advisory glidepaths from the navigator carry the same caution — the barometric altimeter remains primary for every stepdown and for the MDA (AIM 5-4-5; IPH ch. 4).

Dive-and-drive — descend to each stepdown altitude, level off, repeat, then run level at the MDA to the MAP. It works, but multiple level-offs at low altitude invite instability.

CDFA — a constant-rate descent from the FAF that reaches the MDA near the visual descent point. A stabilized, constant-angle descent can be held from the FAF to landing, reduces CFIT exposure, and minimizes visual-illusion effects (IPH ch. 4; AC 120-108). One trap: the MDA is still an MDA — plan to level off or go missed at it, because descent below an MDA without the 91.175(c) references is never authorized.

Subtract the touchdown zone elevation (TDZE) from the FAF crossing altitude and divide by the time inbound. The IPH example: FAF at 2,000 ft MSL, TDZE 400 ft, 2 minutes inbound — 800 fpm (IPH ch. 4). Cross-check with the 300-feet-per-NM rule for an approximate 3° path: at 5 NM you should be about 1,500 ft above TDZE; at 2 NM, 600 ft (IPH ch. 4). Or just pull the rate from the descent table in the back of the TPP using the published angle and your groundspeed (AIM 5-4-5).

Configured, on speed, on the planned flight path, with a descent rate of less than 1,000 fpm — established before descending below 1,000 ft above the airport or TDZE for any straight-in instrument approach. Descent rates greater than about 1,000 fpm below 1,000 ft AGL are unacceptable in either the instrument or visual portion — a human-perception limit, not an aircraft one (IPH ch. 4). Significant speed or configuration changes during the approach degrade situational awareness and complicate the decision at the MAP.

Only when all three 91.175(c) conditions are met:

• Continuously in a position to land on the intended runway using normal maneuvers and a normal descent rate
• Flight visibility at or above the published minimum
• At least one of the ten visual references distinctly visible and identifiable

Otherwise level at the MDA to the MAP and go missed. The full reference list and the transition to landing are covered under Task VI.E.

A letter suffix means the procedure is circling-only — it's expected to end in a circling maneuver, and no straight-in minimums are published. As a general rule that happens for one of two reasons: the final approach course is aligned more than 30° from the runway centerline, or the descent gradient from the FAF to the threshold crossing height exceeds 400 ft per NM (IFH ch. 1). You may still land straight ahead if you see the runway early enough for a normal descent, but only circling minimums apply.

An ATC clearance for the RNAV procedure authorizes you to use any line of minima for which the aircraft is certified — a WAAS aircraft can take LPV or LP; a GPS-only aircraft is limited to LNAV (AIM 5-4-5). Publishing up to four lines (LPV, LNAV/VNAV, LNAV, circling) on one chart is deliberate: if WAAS service becomes unavailable, all GPS-equipped aircraft can still revert to the LNAV MDA (IPH ch. 4).

Tune, identify, monitor. Set the frequency from the chart's briefing strip, then listen to the station identifier before relying on the instrument for navigation (IFH ch. 9).

• The frequency plan itself punishes a mis-set digit: VOR assignments between 108.0 and 112.0 MHz use even tenths, avoiding conflict with localizer frequencies, which use the odd tenths in that range — one knob click can put a different facility's needle in front of you (IFH ch. 9)
• Watch the flags: an OFF flag or blank TO/FROM window means the signal is unreliable (IFH ch. 9)
• For an RNAV approach, the equivalent step is loading the procedure from the current database — building it point-to-point doesn't assure compliance, and CDI/RAIM sensitivity won't ramp down (IFH ch. 9)

No procedure turn may be made — unless ATC clears you for it — when you're:

• On a radar vector to the final approach course or fix
• Flying a timed approach from a holding fix
• On a procedure marked "No PT"

If you're unsure whether a course reversal is expected, ask before the FAF (91.175(j)).

The minimum altitude at the stepdown fix becomes your MDA. Stepdown fixes exist to authorize a lower MDA after you've passed an obstruction — no fix, no lower altitude. And if circling minimums are higher than that stepdown altitude and you're circling, circling minimums control (IFH ch. 1).

• Loss of RAIM/integrity before the FAWP: the approach mode won't go active, CDI sensitivity never ramps down — don't descend; fly to the MAWP and execute the missed approach (IFH ch. 9)
• WAAS unavailable: revert to the LNAV MDA and fly it as a lateral-only approach — GPS-only service is available nearly 100 percent of the time (IPH ch. 4)
• Loss of the navigation source entirely is a failure you must recognize and report to ATC (VI.A S5; V.A S7)

Consult the Inoperative Components or Visual Aids Table printed inside the front cover of the TPP. Example from the IFH: an approach with a malfunctioning MALSR can still be flown, but minimum visibility increases by ¼ SM (IFH ch. 1). If more than one component is inoperative, apply only the highest single penalty — the increases don't stack (IFH ch. 10). Also check chart notes: some procedures state the inoperative table doesn't apply to a specific component.

When you fly the approach — straight-in or circling — at a speed above the upper limit of your certified category. The category itself comes from 1.3 Vso (or Vref) at maximum certificated landing weight and never changes, but the minimums you use follow the speed you actually fly (IPH ch. 4). Details and the category speed bands are covered under Task VI.D.

Under Part 91 you may begin the approach regardless of reported weather — but the bottom doesn't move: if flight visibility is less than prescribed, execute the missed approach regardless of the reported visibility (IFH ch. 10; 91.175). Treat a downward trend as a decision trigger:

• Get the latest weather before the FAF and rebrief the miss — the decision at the MDA should be recognition, not deliberation
• A worsening trend makes your alternate and fuel live numbers — you must land with a 45-minute reserve (91.167); holding to await improvement or proceeding to another airport are both legitimate requests (IFH ch. 10)
• The wrong wind-and-visibility combination can make every approach at an airport unusable — know which other procedure you'd fly before you need it (IPH ch. 4)