How do I read an instrument approach chart?

Read an instrument approach chart in a fixed sequence: confirm the airport, runway, procedure and chart validity; read all notes; trace the lateral route in the plan view and altitudes in the profile; choose the correct minima; then brief the missed approach. Cross-check the loaded avionics against the plate fix by fix.

In our Aviation & Real-World Flying guidance, approach chart and approach plate mean the same document. Charts from different authorities and publishers arrange information differently, so no universal symbol guide overrides the legend printed for that chart series. For real flight, use only current authorised charts and approved navigation data.

Instrument approach chart sections explained

An instrument approach chart combines procedure identification, a top-down route, a vertical profile, landing minima and missed-approach instructions.

An approach plate is only one part of the chart set. Departure procedures, arrival procedures, airport diagrams and en-route charts serve different purposes; our guide to selecting and cross-checking aviation charts in a simulator explains how those documents fit together.

Approach chart legend: symbols and abbreviations that matter

An instrument approach chart legend explains the fix symbols, altitude notation, line styles, navigation aids and terrain markings used by that publisher.

Do not transfer symbol meanings blindly between chart families. Jeppesen charts, national authority charts and simulator-generated plates may depict the same procedure with different typography and panel arrangements. Readers using that format can follow our separate explanation of Jeppesen briefing strips, symbols and minima.

What do IAF, IF, FAF, FAP, MAP and MSA mean?

• IAF — initial approach fix: a point where an initial approach segment begins. A procedure may have several IAFs serving different arrival directions.
• IF — intermediate fix: a point beginning or lying within the intermediate segment, where the aircraft is positioned for final approach.
• FAF — final approach fix: the beginning of the published final segment on many non-precision and RNAV procedures. US-style plates commonly depict a non-precision FAF with a Maltese cross, but that symbol is not universal.
• FAP — final approach point: commonly the point where an aircraft established on the final course intercepts the glide path at the published altitude. Terminology varies with procedure design and charting standard.
• MAP or MAPt — missed approach point: the latest published point at which the missed approach is commenced when the required visual references have not been obtained. It may be defined by a fix, threshold, DME distance or timing.
• VDP — visual descent point: a point from which a normal visual descent may be started when the required references are visible. It is not the missed approach point and does not authorise descent by itself.
• MSA — minimum sector altitude: an emergency or situational-awareness altitude providing the stated obstacle clearance within the printed sectors and radius. It is not a route, an approach segment altitude or permission to descend.

How are altitude restrictions shown?

Altitude typography tells you whether a fix must be crossed at, above or below the printed value, but the exact notation depends on the chart standard.

• On many US-style charts, a line beneath an altitude means at or above, a line above means at or below, and lines above and below mean mandatory.
• Two stacked altitudes may define a window: cross no lower than the bottom value and no higher than the top value.
• A segment altitude applies until the next defined point; it is not automatically a target altitude for unrestricted descent.
• Altitudes may be printed in feet or metres. Check the unit rather than assuming feet.

The profile view is schematic and may not be to horizontal or vertical scale. Use the printed distances, fixes and altitudes, not the apparent angle or spacing of the drawing.

How do I read an approach plate step by step?

Read an approach plate in the same order before every approach so a missing item is easy to detect.

1. Verify the identity. Match the airport name and identifier, runway, procedure type and suffix. ILS Y and ILS Z are separate procedures, not difficulty grades or quality levels.
2. Check chart validity. Confirm the issue or effective information against the material intended for the flight. In a simulator, also check whether the scenery and navigation database represent the same runway layout.
3. Read every note. Look for required DME or GNSS, RNP values, temperature limits, remote-altimeter restrictions, night prohibitions, speed limits and equipment failures that change the minima.
4. Identify the expected entry. Find the IAF, feeder route, transition or vectors-to-final entry that matches the clearance. Do not fly an entire procedure transition merely because the FMS inserted it.
5. Set the navigation references. Note the navaid frequency and identifier, final approach course, communications and any separate DME source. Verify the identifier even when the simulated avionics tune automatically.
6. Trace the lateral path. Follow the cleared route from the entry through the intermediate segment, FAF or FAP, runway and MAP. Include procedure turns, holds, turn directions and maximum speeds.
7. Trace the vertical path. Read every minimum, maximum and mandatory altitude in sequence. Identify the glide-path intercept altitude or non-precision step-down fixes and check where descent is actually authorised.
8. Select the applicable minima. Choose the line matching the approach guidance available and the aircraft category required by the planned speed. Include conditional notes and visibility requirements.
9. Set the correct altitude reference. Confirm QNH or the specified pressure source, then set the appropriate DA or MDA. Do not set a parenthetical height value as though it were a barometric altitude.
10. Brief the missed approach. Read the initial climb, track or heading, climb-before-turn requirement, holding fix and final altitude. Compare the coded missed approach with the printed instructions.

How do I read an ILS approach chart?

To read an ILS approach chart, identify the localiser frequency and course, glide-slope intercept altitude, applicable ILS minima and complete missed-approach sequence.

1. Check the procedure title. Confirm that the chart authorises an ILS to the intended runway. A combined title may also publish localiser-only minima for use when the glide slope is unavailable.
2. Find the localiser details. Note the frequency, identifier and inbound front course. If DME is required, establish whether it comes from the ILS installation or a different station.
3. Find the intercept altitude. The profile view gives the altitude at which the glide slope should be intercepted while established on the localiser. Intercept from below unless the published procedure explicitly provides otherwise.
4. Check the final segment. Note the FAP or equivalent point, glide-path angle, threshold crossing information where shown and any restrictions before glide-slope intercept.
5. Select ILS minima. Use the ILS DA/H and visibility for the applicable category only when valid localiser and glide-slope guidance are available and all procedure requirements are met.
6. Brief the missed approach. At DA, continue only when the governing visual-reference and position requirements are satisfied; otherwise begin the missed approach and follow its published restrictions.

A glide-slope capture does not prove the aircraft is correctly established. Capturing from above can produce an unstable descent or, in some simulations, apparent capture of an unintended lobe. Verify localiser alignment, intercept altitude, descent indication and distance before following it.

Also check the active cockpit source. An approach can be drawn correctly on the moving map while the flight director is still following GPS rather than the localiser. Some avionics change source automatically; others require manual selection or arming.

How do I choose the correct approach minima?

Choose approach minima by available guidance, procedure notes and aircraft category—not simply by selecting the lowest line in the table.

• DA — decision altitude: a barometric altitude at which a missed approach must be initiated if continuation requirements are not met. The aircraft does not level at DA.
• DH — decision height: the corresponding height above a stated datum. On some low-visibility operations it may be associated with radio-altimeter use.
• MDA — minimum descent altitude: the lowest authorised altitude for the applicable non-precision or circling operation until further descent is permitted.
• HAT and HAA: height above touchdown and height above airport respectively. Parenthetical height figures provide a height reference; they are not normally the value entered into a barometric altitude selector.
• OCA/H: obstacle clearance altitude or height. In charting systems that publish OCA/H rather than operating minima, an operator may have to derive the usable minimum under its approved rules.

Visibility and cloud base are not interchangeable. A minima table may require flight visibility, reported visibility or runway visual range; the governing rules and table headings determine which value applies.

Aircraft categories are primarily speed-related, and the precise method is jurisdiction-dependent. If the planned manoeuvring speed requires a higher category, use the higher category and observe any category-specific restrictions. Our detailed guide to matching approach minima to aircraft category covers that selection without reducing it to aircraft size.

Advisory vertical guidance does not change the published minima type. If the selected line is LNAV, localiser-only or another MDA-based procedure, an FMS-generated glidepath does not turn it into an ILS or LPV approach.

Why does the approach chart not match my simulator?

An approach chart usually disagrees with a simulator because the chart, navigation database, avionics and airport scenery represent different revision cycles or capabilities.

• Runway number mismatch: older scenery may retain a previous runway designation after magnetic variation caused a real-world renumbering.
• Missing or renamed fixes: the simulator's navigation data may represent an older or newer procedure design.
• Different Y or Z approach: the wrong procedure variant or transition may have been loaded.
• Route discontinuity: a vectors segment or manually flown leg may intentionally appear as a gap rather than a connected magenta route.
• Unavailable LPV or vertical guidance: the chart may publish capability that the simulated receiver or aircraft implementation does not support.
• Small course difference: rounding and magnetic-variation updates can produce a one-degree discrepancy without changing the underlying path.
• Missing missed-approach legs: some avionics model holds, altitude legs or manual termination points differently from the chart.

Start by verifying the airport, runway, procedure suffix and transition. Then compare every fix, course, distance and altitude. For a coherent simulator exercise, use a chart and navigation-data cycle that describe the same procedure; a historical mismatch must never be treated as suitable operational material for real flight.

Which approach-chart mistakes cause the most trouble?

The most consequential errors involve descent authority, minima, navigation-source selection and missed-approach timing.

• Using MSA as a cleared altitude: remain at the applicable published segment altitude unless a valid clearance and procedure permit otherwise.
• Descending because the magenta path descends: the charted restriction governs even when the FMS displays a smooth vertical path through it.
• Using the wrong altitude from the minima box: DA or MDA is not the same as the parenthetical height above touchdown or airport.
• Following advisory VNAV below MDA: generated vertical guidance does not authorise descent below the published minimum.
• Failing to identify the navaid: a tuned frequency or displayed localiser needle should be checked against the published identifier.
• Loading the full transition after accepting vectors: this can command a turn away from final towards an unwanted IAF.
• Mixing pressure or distance units: check feet versus metres, hectopascals versus inches of mercury, and whether distance is from a station, fix or threshold.
• Turning early on the missed approach: begin the climb as required, but do not make a turn before the point or altitude specified by the procedure.

What should a complete approach briefing include?

A complete briefing states the procedure, entry, lateral and vertical paths, minima, landing cues and missed approach in a compact, repeatable order.

Airport and approach; runway; transition or vectors; navigation source, frequency and identifier; final course; FAF or FAP and intercept altitude; DA or MDA and visibility; runway lighting; missed-approach track, altitude and hold; special restrictions and expected threats.

Complete the briefing before the high-workload final segment, then verify the aircraft against the chart rather than reading while chasing the guidance. The next task is cockpit execution: loading the correct transition, intercepting final, managing the navigation source and flying the missed approach are covered in our simulator instrument-approach flying walkthrough.