2.3 - Approach, vertical profile

Right below the missed approach summary, there is a sumamry of all waypoints and altitudes in the approach: 1. The approach initiates at an altitude of 4100ft, a 1 minute holding pattern is available at DUMBA; 2. A descent to 3200ft (or above) should be initiated after DUMBA; 3. A descent to 1800ft (or above) should be initiated after CEPIN; 4. The glideslope must be captured and followed after AXMUL, and normal landing accomplished.

On the bottom of this section, the minimums for this approach are displayed accordingly to the approach condition and the aircraft type. Let's start by discussing three new terms: minimum descend altitude (MDA), missed approach point (MAP, MAPT) and decision height (DH):

1. The minimum descent altitude is the lowest altitude an aircraft can descend without having the runway in sight. It is only used for non-precision (VOR, NDB, ...) and circling approaches, and should be maintained until either having the runway in sight or executing the missed approach (at MAP).

2. The missed approach point is equivalent to the decision height, and is the time to decide whether to land of to execute the missed approach - it is also used only for non-precision and circling approaches. MAP is determined by either a DME distance or timing from a determined fix.

3. The decision height is the lowest altitude an aircraft performing a precision approach (such as ILS) can go without having the runway in sight, it is also the time to decide whether or not to land. The decision height will be exactly at the same place as MAP if the glideslope is correctly followed.

Now, use the chart below to determine your aircraft category:

In this example, there are three approach conditions: full ILS (both LOC and GS), LOC only, sidestep runway 28L and circling - all of them have different minimas. To detemine MDA/DH use the table provided on the plate. For example, a category C aircraft performing a full ILS approach will have a DH of 213ft and a minimum RVR (runway visual range) of 1800ft while a category D aircraft performing a circling approach will have a MDA of 1160ft with a minimum visibility of 3 statute miles. Please ignore the small numbers, they are radio altimeter settings and are normally used only on CATII/CATIII ILS approaches.

A sidestep approach consists of landing on a parallel runway when the runway being approached is in sight. In this example, you would descent to 460ft and wait until you have the runway in sight, then turn left and land on the parallel ruwnay.

2.4 - Airport plan view

The airport plan view provides airport information such as runway lighting, touchdown zone altitude, airport altitude, and the most important: MAP location and timing, based on the final approach fix. In this example, AXMUL is our final approach fix (FAF) because it has a cross right below it on the vertical profile. If your aircraft has DME installed, you can use it to precisely determine the MAP location; but if it doesn't, you'll have to use the not-so-precise knots/time table to determine the MAP - simply choose the speed you're flying and start the chonometer, when it reaches the time shown in the table, you're right above the MAP.

In short ...

Let's summarize the whole approach:

1. Look at all the information the plate provides - determine the approach minimas, brief the approach and missed approach procedures, determine DH/MDA, etc.
2. Set the ILS frequency, select a initial approach fix (IAF) and get to the initial altitude. Remeber to enter the holding pattern if needed
3. Descent to recommended altitudes, intercept the localizer and glideslope
4. Decide whether to land or execute the missed approach
5. Accomplish normal landing or fly the published missed approach as briefed

Other types of approaches

There are two important procedures that I'd also like to dicuss here: an approach with a proceure turn and a circling approach:

Procedure turns

An approach plate with a procedure turn looks like this:

Click here to download this plate, in PDF format

The main difference of this type of approach is that you head outbond of the airport for a while, then finally turn back and accomplish normal landing. We'll use the NDB/GPS runway 26 approach to Front Range Airport to exemplify a procedure turn.

This time the IAF is the SKIPI NDB, which can be reached by following the 044 radial from FALCON VOR for 10.6 nautical miles. After crossing the IAF, turn left to heading 080, and within 10 miles, turn right to heading 125 and then left to 305. You should allow enough separation so that you can finally turn to heading 280 and accomplish normal approach/landing. You should be familiar with everything else in ths plate, so there's no need to re-explain.

Circling approach

A more detailed tutorial on how to conduct a circling approach is available here: Circling Approach Tutorial. Again, you should be familiar with everything else on the plate.

The end ...

Phew! I hope you have now learned how to fly a realistic approach on your flight simulator using approach plates. If you have any comment, suggestion or question, please visit the FS Station Forums.