Reading approach charts

Verify the procedure before extracting numbers

Use a current Terminal Procedures Publication (TPP) or equivalent current authorized chart. Confirm airport, runway, procedure type, version/suffix and chart validity, then review procedure, facility, runway and lighting NOTAMs. “ILS Z” and “ILS Y” to the same runway can have different transitions, equipment and missed instructions. A familiar runway number does not identify the whole procedure.

The title describes final guidance and alignment. An approach with a runway number generally has straight-in minima; a letter such as VOR-A indicates a circling-only procedure. Read the equipment and PBN boxes and notes as well as the title: current charting is removing some older slash-equipment naming, so absence of “/DME” does not prove that DME or a suitable RNAV capability is unnecessary. Check the entire approach and missed, including any RNAV missed on a conventional final.

A downloaded chart is useful only if it is the right current chart and accessible in flight. Compare the procedure loaded in the navigator with that chart. Use its legend to decode unfamiliar symbols rather than guessing. This lesson uses original teaching diagrams and invented values; they are not a chart suitable for navigation.

AIM 5-4-5: titles, current equipment/PBN notes and chart requirements · IPH Chapter 6, printed 6-14–6-17: naming and chart/database discrepancies · ACS I.C.K1h, printed page 4: Terminal Procedures Publications

Read restrictions as part of the brief

The briefing strip organizes essential information: final course, navigation frequency or approach identifier, runway and touchdown elevations, notes, communications, and missed instructions. Verify required equipment, approved capability, available altimeter source and any minima increase or unavailable operation. A brief that reads only frequency and final course is incomplete.

Some minima depend on an identifiable stepdown fix, local altimeter setting, operational approach lights, flight director/autopilot use, or another condition. Apply the actual chart notes and current inoperative-components guidance. A note prohibiting the procedure at night or circling on one side of a runway is a restriction, not a recommendation overridden by a clearance. Section 91.175(b) makes the authorized altitude the highest applicable value for the procedure, pilot and available/used aircraft equipment.

Identify cold-temperature requirements, uncompensated Baro-VNAV limits and any current outage that affects a minima line. Those are different issues. When the required altimeter setting is not available and no authorized alternative applies, the approach is not authorized. Do not substitute an unlisted nearby setting. Brief the amended missed procedure if NOTAMs or ATC replace it.

AIM 5-4-5: altimeter source, notes and equipment-adjusted minima · 14 CFR §91.175(b): authorized minimum altitude · AIM 7-3-3–7-3-5: temperature restrictions and corrections

Connect lateral segments with altitude restrictions

The plan view shows the route from above: facilities, initial/intermediate/final fixes, feeder routes, course reversals, arcs, distances and missed holding pattern. The profile view shows the altitude/path sequence. Read them together. A direct course to the runway that looks plausible in plan view does not replace a prescribed transition or authorize early descent.

On FAA charts, an altitude with a line below is a minimum; a line above is a maximum; lines above and below indicate a mandatory altitude. A value without those lines can be recommended for planning. If ATC assigns an altitude, that clearance also applies. When vectored or on an unpublished route, retain the last assigned altitude until established on an appropriate published segment unless ATC assigns otherwise; then obey each succeeding restriction.

Locate the FAF and any stepdown fixes. A Maltese cross marks a nonprecision FAF; the lightning-bolt symbol identifies the precision final approach point at published glideslope interception. Following vertical guidance outside that final point does not excuse preceding restrictions. Identify the procedure’s MAP from the profile and guidance type; it may be a fix, waypoint, facility, distance or timing from the FAF.

Distinguish a minimum safe altitude (MSA) used for emergency reference from a route descent authorization. A terminal arrival area (TAA) has its own defined areas and approach-clearance rules. Neither the largest nearby altitude number nor a map’s terrain picture supplies permission to descend.

AIM 5-4-5: plan/profile symbols, prescribed altitudes, MSA and TAA · AIM 5-4-6: approach clearance · 14 CFR §91.175(i): assigned altitude until established

Choose the actual minima line

One chart can support different operations. ILS uses localizer and glideslope to a DA/DH; LOC alone uses lateral guidance to an MDA. On an RNAV (GPS) chart, LNAV and LP are lateral-only operations to an MDA; LNAV/VNAV and LPV provide approved vertical guidance to a DA when the installation and available service support them. An advisory descent cue does not upgrade an MDA operation.

DA is an altitude referenced to mean sea level; DH is a height above its specified reference. MDA is also an MSL altitude. The separate height above touchdown (HAT) or airport (HAA) is not a second lower altitude to dial into the altimeter. On FAA TPP charts, the parenthetical ceiling/visibility figures are for military use and are not used by civil pilots. Read the chart legend to distinguish those values. Confirm both altitude and required visibility for the selected line and category.

AIM 5-4-5: approach types, RNAV minima and chart terminology · AIM 5-4-20: published minimums and MAP · IPH Chapter 4, printed 4-19–4-20: MDA, DA and DH · IFH Chapter 1, printed 1-26: landing minima, HAT/HAA and military parentheses

Use the applicable category and speed

Aircraft approach category is based on the certified reference landing speed VREF, if specified, or 1.3 VSO at maximum certificated landing weight. It is not selected from today’s groundspeed or reduced merely because the airplane is lighter. Verify the category from applicable aircraft information, then account for the speed actually needed for the operation.

If operating above the category’s upper limit, use the appropriate higher-category minima. For an invented example, a Category A airplane needing 100 knots on the approach uses Category B minima; 130 knots uses Category C under this recommended method. Those are category examples, not recommended speeds. Wind, icing, maneuvering or non-normal conditions may require speed and minima changes. A high groundspeed from tailwind does not itself change the certification category, but it affects turn radius and circling protection.

For circling, confirm the applicable speed/category, altitude-dependent protected area and all restrictions. If appropriate higher-category minima are not published, do not assume you can circle at a speed outside the protected category. Select a suitable straight-in approach, another runway or airport, or an appropriate revised operation.

AIM 5-4-7: category basis, speed bands and higher-category use · AIM 5-4-20: circling-area protection

Keep the descent point, missed point and visibility separate

A visual descent point (VDP) marks a point on a straight-in nonprecision final from which a normal visual descent from MDA may begin when the other landing conditions are met. It is not the MAP and not automatic permission to descend. The AIM advises no descent below MDA before the VDP. After it, a safe normal landing can become impractical well before reaching the MAP. If unable to identify a published VDP, fly as though none is provided and assess descent geometry conservatively.

A published vertical descent angle (VDA) is an advisory aid on a lateral-only approach. It does not supply approved vertical guidance or guaranteed obstacle protection below MDA. A “Visual Segment—Obstacles” note deserves particular attention. Seeing the runway late cannot justify diving through MDA or maneuvering steeply to save the landing.

Required visibility is usually statute miles or RVR in feet according to the chart format, while route distances are nautical miles. For ordinary natural-vision operations, §91.175 requires flight visibility at least the prescribed value for descent below minimums and landing. A favorable ground weather report alone does not prove what is visible from the cockpit. Use the prescribed RVR conversion when applicable; do not invent an interpolation between table values.

AIM 5-4-5: VDP and advisory VDA/visual-segment limits · AIM 5-4-20: visibility and RVR conversion · 14 CFR §91.175(c), (d), (h): visibility and descent/landing

Brief the landing decision and the complete missed

Below MDA or beyond DA/DH, ordinary §91.175 descent needs all three conditions: continuous position for a normal descent and normal maneuvers to the intended runway, sufficient flight visibility, and a listed runway reference distinctly visible and identifiable. A runway glimpse does not supply the other two. Approach lights alone allow descent only to 100 feet above touchdown-zone elevation, unless the red terminating or side-row bars are also distinctly visible and identifiable. Other listed runway references can support further descent when all conditions remain satisfied.

Read the whole missed text, not just the small profile icons. Identify initial climb/track, any altitude before turn, turning direction, required gradient, facility/waypoint, holding fix, altitude and equipment. Verify aircraft performance for the gradient using actual AFM/POH data and anticipated groundspeed. An approach clearance normally includes its published missed unless ATC specifies an alternative; obtain clarification before starting if the alternative is unclear or unsupported.

At DA or the applicable MAP without landing conditions, initiate the missed promptly. If a safe landing becomes impossible earlier, begin the appropriate go-around/climb but preserve the specified path to the MAP before an early missed turn unless cleared otherwise, observing maximum altitudes. Late, below-minimums or circling go-arounds do not automatically retain the normal missed obstacle/separation assurance.

14 CFR §91.175(c)–(e): visual conditions and missed triggers · AIM 5-4-21: missed instructions, gradients and early/late limitations · AIM 5-5-5: missed-approach responsibilities

Practice extracting a decision-ready brief

Invented study brief: a charted lateral-only procedure has a FAF crossing altitude of 2,400 feet, a stepdown fix requiring 1,600 feet, an MDA of 1,100 feet MSL and visibility 1 statute mile for the applicable category. A note using an authorized remote setting raises MDA by 80 feet; the local setting is unavailable. These are arithmetic targets, not a real procedure.

1. Identify the authorized altimeter source and apply the note: MDA becomes 1,180 feet. Do not confuse a printed height above airport with that altimeter altitude.
2. Plan a descent that respects the 2,400- and 1,600-foot crossing limits and the 1,180-foot floor; an advisory path does not erase them.
3. Identify how VDP and MAP are determined and when a normal visual descent is still possible.
4. State the three descent conditions and the approach-light limit; choose a missed when they are absent.
5. Read and brief the entire missed, required climb performance, sources and next decision before crossing the FAF.

Repeat using an actual current chart with your instructor and the aircraft’s real capability. Have another person point to a note, a lost component or a higher speed; explain how the usable operation changes. No simulator is needed to practice this extraction, but actual chart use and flight performance need training.

AIM 5-4-5: altimeter/minima notes and restrictions · AIM 5-4-20: category and minima · AIM 5-4-21: missed preparation

FLIGHT SCENARIO

What would change your plan?