Reading FAA Instrument Approach Charts

An FAA instrument approach chart, often called an approach plate, is the published picture of a standard instrument approach procedure. The procedure itself is designed to the US TERPS criteria and prescribed under 14 CFR Part 97, and 91.175(a) requires a pilot who needs an instrument approach to a civil airport to use it. The chart turns that legal text into a page that can be briefed before the approach and glanced at during it: where to go, how low to descend at each point, and when to give up and fly the missed approach.

FAA charts follow a fixed layout, set out in the FAA Aeronautical Chart Users' Guide: margin data, a briefing strip, the plan view, the profile view, the landing minimums and an airport sketch. Learning that order is most of the skill. ICAO-format charts in European AIPs and commercial charts carry the same information in a different arrangement (see reading ICAO instrument approach charts). Examples below use the ILS or LOC RWY 14R at Boeing Field, Seattle (BFI), in the edition valid from 3 September to 1 October 2026.

The Terminal Procedures Publication

The Terminal Procedures Publication (TPP) contains the instrument approach procedure charts, airport diagrams, departure procedures, standard terminal arrivals and charted visual flight procedures. It also holds text sections for take-off minimums and obstacle departure procedures, radar minimums and IFR alternate minimums, a hot spot page, the chart legend and a rate-of-descent table. It is issued in regional volumes, such as NW-1, on a 56-day cycle with a change notice at 28 days; charts taken from the FAA's digital edition, like the BFI example, carry a 28-day period in their side margins. Between editions, changes to procedures such as raised minimums or an unusable navaid are issued as FDC NOTAMs, which belong in every pre-flight check.

The margins identify the chart. The city and state appear top and bottom, the approach and landing number with the responsible organisation, for example AL-384 (FAA), at the top centre, and the procedure title in both the top and bottom margins. The title names the system giving final approach guidance and the runway, as in ILS or LOC RWY 14R; "or" means either system may be used. A circling-only procedure takes a letter instead of a runway, as in VOR-A, and several procedures of one type to the same runway are told apart by letters from the end of the alphabet, as in RNAV (GPS) Y RWY 14R. Above the title, a five-digit Julian date gives the latest revision: 26022 is day 22 of 2026. The side margins give the volume and its period of validity, and the bottom left the procedure amendment number with its AIRAC date, such as Amdt 32 29DEC22.

Briefing strip and notes

The briefing strip consists of three rows above the plan view.

• Top row: the primary navaid with identifier and frequency (for a WAAS approach, the WAAS channel and reference path indicator, such as W14A), the final approach course, and the runway data. At BFI it reads LOC/DME I-BFI 110.9 Chan 46, APP CRS 135°, Rwy Ldg 9120, TDZE 18 and Apt Elev 22. Rwy Ldg is the shorter of the declared landing distance available and the runway length less any displaced threshold, which is why it can be less than the physical length. An underlined frequency means no voice is transmitted on it.
• Middle row: the notes box, the approach lighting system and the full missed approach text.
• Bottom row: the frequencies, from left to right in the order used on arrival (ATIS, approach, tower in a bold box, ground). A star marks a part-time facility, and "(CTAF)" after a frequency shows that it is also the common traffic advisory frequency, as on the tower frequency of a part-time tower.

The notes box carries equipment requirements ("DME and RADAR required"), restrictions such as "Circling Rwy 32R NA at night", visibility increases for inoperative lights, remote altimeter notes and symbols:

Plan view: feeder routes, IAFs and MSA

The plan view shows the procedure from above, to scale unless concentric rings, an inset or a zigzag scale break say otherwise. It shows feeder routes and the segments defined in 14 CFR 97.3:

• feeder routes from the en route structure to an initial approach fix (IAF), which a pilot cleared for the approach is expected to fly;
• the initial approach, from the IAF to the intermediate fix (IF);
• the intermediate approach, from the IF to the final approach fix;
• the final approach, from the final approach fix to the runway or missed approach point;
• the missed approach, drawn as a hatched track with an arrow.

A route label such as "2200 to ISOGE 322° (16.1)" gives a minimum altitude, a course and a distance in NM. Altitudes printed along a route are minimums. At fixes, the bar convention applies: a line under the figure is a minimum, a line over it a maximum, both lines a mandatory altitude, and no line a recommended altitude. Speeds use the same bars, so "200K" with a bar above is a maximum of 200 kt.

A procedure turn barb or a hold-in-lieu of a procedure turn shows where the course reversal is made. It must be flown when charted unless the route is labelled NoPT, the aircraft is radar vectored to final, or a timed approach from a holding fix is being flown. The profile states the limit within which the turn must be completed, normally 10 NM.

The minimum safe altitude (MSA) circle gives at least 1,000 ft of obstacle clearance for emergency use, normally within 25 NM of the navaid, waypoint or airport reference point named in it. It may be split into up to four sectors, each at least 90° wide, and it does not assure navigation signal coverage. On RNAV procedures built on the "T" design, terminal arrival area icons may replace it; unlike MSAs, TAA altitudes are usable operationally once cleared for the approach (see minimum safe altitudes).

Obstacles selected by the approving authority are charted with their elevation in feet MSL, the highest with a bolder symbol, and ± after the figure marks doubtful accuracy, used for vegetation and ships. Brown terrain tints appear when terrain in the plan view rises more than 4,000 ft above the airport, or at least 2,000 ft above it within 6 NM of the airport reference point.

Profile view: altitudes, glide slope and missed approach

The profile view shows the descent from the side, with the distances between fixes rounded to tenths of a NM.

On a precision approach, a lightning-bolt arrow marks the glide slope intercept altitude, at BFI 1600 ft; the point where the glide slope is intercepted at that altitude is the precision final approach fix, where the final approach segment begins. A note gives the glide slope angle and threshold crossing height, here GS 3.00° and TCH 39, and warns when a visual glide slope indicator is not coincident with the ILS. Stepdown altitudes inside the final approach fix, such as the 1080 at SOTEE, apply only to the lines flown to an MDA, such as the localiser-only line.

On a non-precision approach, a Maltese cross marks the final approach fix. Where none is charted, the final segment begins where the aircraft is established inbound on the final approach course. The track descends to the MDA, then runs level to the missed approach point, where the hatched missed approach track begins.

The visual descent point (VDP), a bold V drawn like a solid downward arrowhead above the track on a dashed line (at BFI, I-BFI 3.4 DME), marks where a normal descent from the MDA to the touchdown point can begin. Pilots should not leave the MDA before it. An advisory vertical descent angle, written as an angle with a TCH, helps a stabilised descent but gives no obstacle protection below the MDA; where obstacles in the visual segment could destabilise the approach, the chart shows no angle and says "Visual Segment-Obstacles" instead. The missed approach appears three times: as text in the briefing strip, as a track in the plan view and as up to four icons in the profile. Where applicable, a time and distance table below the airport sketch gives the time from the final approach fix to the missed approach point at several groundspeeds.

Minimums section and approach categories

The minimums section sits below the profile, one line per type of approach: S-ILS, S-LOC, LPV, LNAV/VNAV, LNAV, circling and, where parallel runways exist, sidestep. LPV, LNAV/VNAV and ILS lines are flown to a decision altitude (DA); LNAV, LP, localiser and circling lines to a minimum descent altitude (MDA) (see instrument approach procedures).

Each entry reads in the same order. At BFI the S-ILS 14R line is 308/40 290 (300-¾):

The columns are approach categories. Under 14 CFR 97.3 they are based on VREF, or 1.3 VSO if no VREF is specified, at maximum certificated landing weight:

A pilot who must manoeuvre faster than the category's upper limit should use the minimums of the higher category: an aeroplane in Category B circling at 145 kt uses Category D. A negative C, white on black, on the circling line means the larger circling areas developed since late 2012, whose radius grows with the altitude of the circling MDA. Notes such as "Circling NA for Cats C and D northeast of Rwy 14L-32R" restrict where circling may take place. Notes also adjust minimums, for example raising the visibility when the approach lights are inoperative. See obstacle clearance and approach minima for how the figures are derived.

Airport sketch, airport diagram and hot spots

The airport sketch in the bottom corner draws the runways to scale and oriented to true north, with their dimensions. The airport elevation, the highest point of the usable runways, is boxed at its upper left, and the touchdown zone elevation (TDZE), the highest point in the first 3,000 ft of the landing surface, at its upper right; circling-only charts show no TDZE. Approach lights appear as symbols at the runway end: at BFI an A4 with a dot is the MALSF, since A4 stands for a MALS (or SSALS) and the dot adds sequenced flashing lights, while a negative (white on black) symbol means pilot-controlled lighting. A circled P marks a PAPI, and notes list the runway lights, such as HIRL Rwy 14R-32L.

Complex airports also have a separate airport diagram for ground movement, not for approach and landing. It shows runways with their magnetic headings, taxiways, hold lines, ILS critical areas, parking areas and the frequencies. A hot spot is a confusing intersection with a history or risk of surface incidents, shown by a brown circle or ellipse labelled HS 1, HS 2 and so on, with a description on the hot spot page at the front of the TPP (see taxiing and runway incursion prevention and aerodrome charts and airport diagrams).

Library articles are written for study and exam preparation. They do not replace your aircraft's approved documentation, your operator's procedures or the regulations themselves.