Holding Patterns

This blog is covering two separate lessons both of which happened about two weeks ago.

The first lesson was in the sim. This lesson was basically my introduction to holding patterns. I started out with some ground going over the different types of holding pattern entries and how to interpret an ATC non-published holding clearance.

A published holding procedure is one that is depicted on an chart. A non-published holding procedure is one that ATC can assign that is not depicted on any charts and as a pilot, I must interpret what entry I must use and which headings I need to fly in order to satisfy the clearance.

Here is a basic holding pattern:




You fly inbound for one minute, execute a 180 degree standard rate turn (which should take one minute), fly outbound for one minute, and then another 180 degree turn back to the inbound leg. The result is a four minute delay for ATC to work with towards traffic spacing and weather avoidance.

There are three different ways to enter a holding pattern. There's direct, teardrop, and parallel entries.


A direct entry is just simply flying to the holding fix, and then beginning the holding pattern right away. It is best used if you are flying a heading that is close to the inbound heading.

A teardrop entry is used when you are coming at the fix from the opposite direction and on the opposite side of the inbound path as the hold. Upon crossing the fix, you fly 30 degrees off the outbound heading for one minute and then turn back to the inbound course.

A parallel entry is used when you are on the same side of the inbound course as the hold and you are coming from the opposite direction. It is the most complicated of the three. Upon crossing the fix, you turn and fly the outbound heading parallel to the inbound course for one minute, and then turn towards the inside of the hold about 240 degrees to intercept the inbound course.

Before you can identify which entry you need to use, you must first figure out your aircraft's location in reference to the holding pattern. This is fairly easy with a published hold. Here is an example of a published hold on Clarksburg's ILS approach:



As you can see, the headings are clearly illustrated (211 inbound, 031 outbound) and the hold is executed on the fix FONTZ intersection. So imagine you are flying your aircraft directly to FONTZ. If your heading is south, that means you are coming from the north and you would do a direct entry. If coming from the south, you would do a teardrop entry. If coming from the west, you would do a parallel entry.

Figuring out what entry to use becomes difficult when you are instructed to fly a non-published hold. Imagine that the hold above is not published. This is how ATC would instruct you to hold at FONTZ:"577SP, hold northeast of FONTZ intersection on the 031 radial, standard turns, expect further clearance in 10 minutes."

The best way to deal with non-published holds when they are assigned is to just draw them out on paper. I would draw a small circle to represent FONTZ, then I would draw a line coming from FONTZ at 031 degrees to represent the 031 degree radial. Since ATC said right turns, I would draw the oval as if flying on that radial to FONTZ and then turning right (right is standard, left is nonstandard). This result in a replica of the above published hold. I would then draw my aircraft headed for the fix in order to figure out which entry to use.

All this while maintaining altitude and heading.

As far as my first holding performance is concerned, I did excellent on my direct and teardrop entries in the sim. However, my parallel was a little all over the place. When I actually got in the plane and flew these holds, only my direct was good. My teardrop and parallel entries were both sloppy. I did get a second chance on those however, and did okay.

One more thing that you must take into account when flying a holding pattern is wind. a tailwind on the inbound course can cause you to fly a longer outbound leg and a shorter inbound leg. Say that you start your time for the inbound leg and it only takes 45 seconds until you reach the fix. If this happens, you extend the outbound leg by 15 seconds. In other words, fly outbound for 1:15 in order to make your inbound leg exactly one minute.

You also have to apply wind drift correction in the instance that you might have a crosswind. If flying the inbound course you are having to correct five degrees, then the rule of thumb is to correct three times that amount on the outbound leg. So you would correct for 15 degrees.



Holds are a little bit tricky but in the end its all about being able to realize your aircraft's location in relation to the holding pattern and basically having the ability to know where your plane is as if you are looking at your flight path from above.