The LOC Approach Chart

"Oh, that's the one with the feather!"

Most localizer approaches are combined with ILS approaches. That is, because the localizer (LOC) is the horizontal guidance navigation system for an ILS. You will see an approach chart called 'ILS or LOC'. There are LOC only charts, and we'll focus on those in this article.

For a complete guide to IFR publications, please refer to the FAA Aeronautical Chart User's Guide. This will give you life, death, and miracles of IFR charts. My article gives you the simplified cliff notes.

Basic Guidance Summary

The LOC provides angular guidance laterally by virtue of a localizer antenna, found at the end of the runway.

By angular, we mean that the precision of the guidance will increase as you get closer to the antenna station (i.e., closer to the runway). Contrary to the ILS, there is no glide slope, and therefore no vertical guidance.

For further details on the specific guidance and geometry, please refere to this article, here.

The Approach Plate

The approach plate - the chart - has unique elements that we will examine in this article. Be warned that this article is not all-inclusive. As new procedures are developed, you will have to use your own intellect (that's your brain) to understand what the procedure wants you to do. For the sake of this exercise, we will examine the LOC runway 21 at KHXD.

Bureaucracy and Dates and Stuff

The date the chart was last revised is reported in the bottom left corner of the plate along with its amendment version (07 December 2017, amendment 6). On the sides you will find the validity dates of the chart (valid from 19 March 2026 to 16 April 2026) - see the second image on the margins.

Top Briefing Strip

The name of the approach is reported on the top right. The name of the approach refers to the navigation equipment required for navigating the final approach segment (FAS). In our case, LOC for Runway 21. It also reports the city, airport name and identifier (HXD).

On the top left of the header, the plate will report the navigation frequency. Since the LOC is a ground-based navigation approach (VLOC), you must have a frequency to tune to. In this case, the frequency is 111.3. The identifier for the localizer, needs to be verified before execution. In this case, it's I-HXD (the morse code is reported on the plan view, see later). If you have Garmin, it will identify the station for you. The channel reported below, 50, is for the Distance Measuring Equipment (DME).

Next to the navigation source information, you have the final approach course (FAC). In this case it's 213 degrees, which for runway 21, makes sense. This course will have to be set on your Course Deviation Indicator (CDI) and should be verified, even if the automation does it for you (in Garmin we trust). The box next to the FAC has runway information, specifically the runway landing length available (4597 ft), the Touch Down Zone Elevation (TDZE) of 18 ft, and the airport elevation of19 ft. These numbers are very important. The runway length available is exactly how much runway you have. If there is a displaced threshold on the back end, this value will account for it, so it's very helpful for exact distances. The TDZE is useful because it can be used to change your minimums, which we'll cover later.

Middle Briefing Strip

On the left side of the middle briefing strip, we typically have two boxes:

1. Procedure Equipment Requirements Notes Box. This includes all requirements for your navigation equipment. We have no special equipment requirements as there is no box (it would be above the notes).

2. Standard Procedure Notes Box. This is where we find generic notes, including alternate airport ATIS, changes to minimums with inop equipment, and more. Furthermore, there can be up to two symbols on the left side:

   1. T - Non-standard takeoff minimums, obstacle departure procedures, diverse vector area, or close-in obstacles. If that T in the upside down triangle is there, please go read the appropriate publication!

   2. A - Non-standard Alternate Minimums. If you planned on using this airport as an alternate for your IFR flight plan, look at the alternate minimums, cause there will be some! Since there is an NA next to the A, it means that you are not authorized to use this approach for alternate airport planning!

On the right side of the strip, you have your Approach Lighting System (ALS), if present. In the case of HXD, there is none, so there is only the textual missed approach information.

Communication Information

The bottom briefing strip, also known as your communication information, provides you with useful information in chronological order. As you approach the field, you should listen to the ATIS, then talk to approach, then to tower, and then to ground. Note that the symbols in the boxes follow general conventions. The star means part-time and the L in the oval means pilot controlled lighting (PCL).

The PlanView

Ok, this one is full of stuff. Let's look at it piece by piece.

Minimum Safe Altitude

On the bottom right we have our Minimum Safe Altitude (MSA), which is 25 NM away from the SAV VORTAC. In order for me not to hit anything within 25 NM of SAV I need to climb to 2600 ft.

'RADAR REQUIRED'

Here's a nerdy and important topic: beginning the approach. Back in the day, ATC services were rare, and as such, most approaches were designed to be flown without ATC vectoring you around. For you to do that, there needed to be a connection between the enroute world and the terminal world (i.e., this chart). If there isn't a connection, then the chart should say 'RADAR REQUIRED' on the plan view, because there is no way for you to navigate from the enroute world to the terminal world on your own. It's the case for this approach, and the text 'RADAR REQUIRED' is promptly shown in the top left of the plan view.

Minimum Route Altitude, Course, and Distance

Each leg of the approach will have helpful information, like your Miminim Route Altitude, your course, and distance to the next fix. In the case of the leg from ZEXUN to JAAMM, you cannot descend below 1800 ft and you will be on LOC course 213 for 7.4 NM.

NAVAIDs (VORs, LOCs, etc.)

The I-HXD LOC, which originates the approach, has its own identification box with useful information, like the identifier (I-HXD), frequency (111.3), morse code, and channel, 50 (for the DME).

The box is bolded because the LOC is the primary NAVAID used for the approach. The same applies for other NAVAIDs, like the Savannah VOR that helps you build your missed approach. In that case, the VOR's name 'SAVANNAH' is reported at the top of the box.

Airports

Airport symbols depict the runways available with simple straight thin lines. Nothing special here. Note that nearby airports may be depicted if their position may be confusing to a pilot flying the approach. There's been many cases of pilots landing on the wrong field because there was another airport along the approach that was mistaken for the destination. In the case of KHXD, we only have one runway.

Localizer Feather

The localizer feather depicts the presence of a localizer antenna. It is not to scale - it just helps the viewer recognize that LOC will be used to navigate the approach. The LOC feather will be depicted with the shaded color on the right side to show it's a front course. Some approaches use a back course (i.e., the localizer antenna is flipped backwards for convenience - like if it serves multiple runways), and the shaded colors will help you notice that (beyond the large letters 'BACK COURSE').

Fixes

Each fix on the approach has five letter identifier names, just like in the enroute world. Except we call them more commonly "intersections". On approaches, we usually call them "fixes". On VLOC approaches, these are depicted with vertical lines perpendicular to the Final Approach Course.

They are paired with a data block, which provides lots of information. In the case of ZEXUN the data block shows the fix's name (ZEXUN) and ways of identifying it. We can use the DME from I-HXD (the localizer) of 13.5 NM. Those are called DME boats, just like the enroute world. However, if you don't have DME, then you can't identify the fix (assuming you don't have GPS). For that reason, RADAR is required on the plate. If it didn't say that, it would also say RADAR underneath the DME boat. That means that ATC can see that fix on their scope (the radar screen) and can tell you when you are at ZEXUN. At the very top, ZEXUN is also qualified as an IF which means as an intermediate fix.

No Procedure Turn

Because there is no procedure turn, you need to proceed on the approach in either of two ways: direct ZEXUN inbound, or vectors to final. RADAR is required for this approach, so you have both options available to you with ATC.

Approach Segments

The approach segments are in a thick black line and retain the various leg information. For example, between ZEXUN and JAAMM, you must be at no lower than 1800 ft on a course of 213 degrees. The distance between ZEXUN and JAAMM is 7.4 NM.

The Missed Approach

The missed approach is depicted in dashed lines.

In the case of KHXD LOC 21, the missed approach is shown in dashed lines after the runway with a turn to the southeast. As a reminder, the missed approach for KHXD instructs the pilot to climb to 800 ft, then right climbing turn to 2000 on to track SAV R-085 to SELER intersection (defined as 21.5 DME from SAV) and hold. The dashed line clearly shows that right turn to intercept R-085. Because the SAV VOR is so far off the chart, a set of zig-zag lines crossing the radial are drawn to indicate "not to scale".

Airspaces and Geography

To provide good situation awareness, the FAA shows terrain and water (if present) as well as complicated airspace, like Special Use Airspaces. KHXD is very clearly defined by the Atlantic ocean and marshland. If appropriate, the FAA will also depict obstacles.

The Profile View

In my mind, the provide view is the heart of the approach, and if I had to keep one section from the entire chart (and burn the rest), this would be it.

The profile view is shown by a thick line that leads to the runway. Some elements are repeated from the plan view, just like distances, some altitudes, fix identification information, and the missed approach.

Fixes

Fixes are labeled at the top of the profile view with a dashed vertical line all the way to the ground. After all, ZEXUN is a lateral designation only (i.e., lat and long). The same identification information from the plan view is reported, here.

The Non-precision Final Approach Fix (FAF)

The non-precision FAF is the maltese cross (it's a templar cross, actually, but I'll shut up) and defines the beginning of the final approach segment (FAS).

The FAF is at JAAMM and has a minimum altitude of 1,800 ft MSL.

Stepdown Altitudes

Non-precision approaches don't have vertical guidance. Therefore, you don't have vertical guidance to follow. What you have is stepdown fixes. These are altitudes that you can descend to on each leg, getting you closer and closer to minimums.

For KHXD LOC 21, you can begin the approach at ZEXUN at or above 1800 ft. After sequencing JAAMM, you can descend down to 760 ft. Only after WOVIN you can descend to the Minimum Descent Altitude (MDA).

Geometry Notes

The profile view often provides some notes concerning the geometry of the vertical path. The Threshold Crossing Height (TCH) and vertical path angle are shown for the final approach segment. For KHXD LOC 21, the vertical descent angle is 3.13 degrees, and the threshold crossing height for that geometry is 40 ft. These numbers are important because they affect other guidance.

Minimum Descent Altitude (MDA), the Visual Descent Point (VDP) and the Missed Approach Point (MAP)

The LOC minimums are based on a Minimum Descent Altitude (MDA), and is clearly depicted by a horizontal line that leads to a dashed line. That indicates that when you reach the I-HXD 0.8 DME (which is the runway), you will have to execute the missed approach. The runway is therefore your missed approach point (MAP). It is not labeled as such - you have to figure it out based on the dashed line and your intellect. Note also that this segment is called the "visual segment" because the approach will no longer protect you from anything - you are responsible from landing safely.

The I-HXD 1.9 DME point is a visual descent point (VDP). The VDP is the point before which a pilot should not descend below minimums even if the runway environment is in sight. The VDP protects you from obstacles, terrain, and conveniently aligns you with the Visual Glide Slope Indicators (VGSI) if present.

Lateral Distances

Leg distances are reported - not to scale - at the bottom of the profile view. On the far right you can see the runway (thicker line).

Missed Approach

Since you will be focusing on the vertical profile as you descend to minimums, the FAA depicts the missed approach in icon format at the top right of the profile view. In the case of KHXD LOC 21, when you reach your MAP, if you don't see the the runway, you have to go missed. Climb straight ahead to 800 ft, then climbing right turn to 2000 to intercept SAV radial 085 to SELER and hold.

Lines of Minima

Below the profile view you will see the lines of minima. The "how low can I go" information. The minimums are categorized by equipment on the left column (LOC, circling) and by categories (A, B, C, D) on the top row. The speeds are based on final approach speed. Category A is <91 kts, Cat B is 91-121, etc.

The 'S' in front of LOCLS means "straight in". There are some approaches that are laterally angled differently and may not be considered "straight in" anymore. The minimums will reflect that angle change.

The minimums are reported in the big numbers: 400-1. That means 400 ft MSL and 1 SM visibility. The smaller number before the parenthesis reports the minimums in AGL. So 400 ft MSL = 382 ft AGL. The values in parenthesis are military minimums that do not apply to us civilians.

The circling minimums may apply to us if we choose to do a circling approach. In that case, for category A minimums, we can fly down the approach but change our MDA to 480 ft. That is a Minimum Descent Altitude (MDA) as well. We cannot descend below that until we are in a position to land. We require 1 SM visibility (the 480-1) and we will be at 461 ft AGL. For a reminder on how to circle, see this article. As mentioned earlier, if you decide to circle, your missed approach point is the runway as well.

Airport Sketch

The FAA charts also show you a summarized airport diagram to increase your situation awareness (SA). It repeats some information from the top header (so you don't have to look up and down too much), including some new stuff. The bolded 'D' at the top means 'Declared Distances', so the reported runway lengths are appropriate to be used for performance calculations. So 4,597 ft are the maximum runway length available for someone who needs to land.

The ALS, along with slope and VGSI locations are shown (P = Papi, V = VASI). The rotating beacon is shown by the star and the control tower is labeled 'TWR'. All runway distances are provided. What is also very useful is the final approach course (FAC) on the top side (213 degrees) to help you understand how you will be approaching the runway.

Other interesting depictions could be the two woven lines perpendicular to runway 21. Those are actually depicting displaced thresholds. That's why the runway length is shown as 5,000 ft and yet the runway available on the header reports 4,597!

On the bottom, further information on the runway lights is indicated. The L in the bolded circle indicates that they are pilot-controlled during after-hour operations.