Our resident flying instructor, John Goodwin will have you going round in circles!

Flying a holding pattern is one of the fundamental procedures when flying IFR.

ATC use holds as a basic tool to achieve separation between traffic during busy periods, and holds are often included in STARS and various approaches like a VOR DME or ILS DME approach to a runway.

A hold is basically a racecourse pattern flown by the pilot at a given fix. That fix could be an NDB, a VOR or an INTERSECTION. The Standard hold is flown with RIGHTHAND RATE ONE turns (a right hand turn at 180 degrees in 60 seconds), and ONE MINUTE LEGS (flying straight for one minute after the turn and before starting the next turn). The hold can be broken down into four distinct parts, the OUTBOUND TURN, the OUTBOUND LEG (or NON HOLDING LEG), the INBOUND TURN, and the INBOUND LEG (or HOLDING LEG).

On the chart I have marked the two common ways that holds are illustrated on an approach plate.

Hold 1 is a hold at the BTG Battle Ground VOR, this is in fact the missed approach hold, and hold 2 is a hold at NACIY intersection which is part of the ILS/LOC RWY28R approach.

Although illustrated slightly differently, both holds show the same information:-

• The direction of the hold is shown by the small arrows on the INBOUND and OUTBOUND legs. In the case of the hold at NACIY, the INBOUND LEG is 279 degrees and the OUTBOUND LEG is 099 degrees.
• The direction and timing of the turns at NACIY, is LEFTHAND RATE ONE turn (NON-STANDARD).
• The length in time of the OUTBOUND LEG. Sometimes this is given as a DME distance but this is not very common.
• Finally and most importantly, the FIX that the hold is based on, which may also include DME distance information from a VOR/LOC. In the case of NACIY it is 14 DME from the 28R LOC.

Next, we will look at flying the hold.

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Flying the Hold

Let us have a look at the NACIY hold in more detail. To establish yourself in a hold you will need some form of radio NAV aids. These days that usually means a VOR NAV Radio. Most aircraft these days will actually have two VOR NAV radios installed which makes instrument flying much easier. It can be done using GPS but this is not very accurate.

In the illustrated example, we are using the 28R LOCALISER as our NAV AID, so even before we even think about holding we MUST have our NAV1 radio tuned to the correct frequency and set the OBS to the correct heading (which is ALWAYS the INBOUND LEG heading. I will discuss how to enter the holding pattern in more detail later, but for now we will assume that we are flying inbound towards NACIY established on the LOC under no wind conditions. More about wind later.

Most holds are carried out at 210 knots in jets and 140 to 160 knots in turboprops and piston engined aircraft.

As we cross over NACIY (28RLOC 14 DME), which by the way is the only time you really know exactly where you are, we immediately start a LEFTHAND RATE ONE turn to a heading of 099 degrees. You must be accurate in your flying or you will never achieve a good hold. As this is a 180 degree turn, it should take us one minute to complete it. As soon as the aircraft rolls out onto a heading of 099 degrees on the OUTBOUND LEG, start your stop watch and fly a heading of 099 degrees for exactly ONE MINUTE. This is the only leg that we actually need to time, although it is useful to time the first inbound leg for reasons explained shortly.

At the end of the ONE MINUTE straight section, we turn LEFT again back to a heading of 279 degrees. In no wind conditions, if you have made perfect RATE ONE TURNS, you should find that you will re-establish onto the 28R LOC with little or no correction. We now fly back INBOUND towards NACIY, which should take approximately one minute to complete, on crossing NACIY we carry out the same procedure again until released by ATC from the hold.

If the INBOUND LEG is considerably different from one minute due to headwind or tailwind conditions, then time may be added or subtracted from the OUTBOUND LEG to make it one minute long.

It is quite straight-forward flying a hold in NO WIND conditions and my advice is to use your autopilot in HEADING MODE and ALT HOLD if possible to assist you.

Next, we see how to adapt the pattern to fly with a wind component.

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Flying a hold with a wind component.

The only time we actually know exactly what the wind is doing to us is when we are flying INBOUND to the fix, as we are usually established on a LOC or a VOR radial. We know that the heading should be 279 degrees, but if we have to fly a heading of 274 degrees to remain established on the localiser, we know that we have now corrected for a wind from our LEFT side. You do not need to know the exact direction or strength of the wind, just which side it is coming from. In this case we turned slightly to the left, so we can deduce that the wind is from our LEFT.

We fly over the fix in exactly the same way as with no wind and turn LEFT onto the OUTBOUND TURN. We know that we had to make a -5 degree (LEFT) correction to stay established on the LOC, so we now must apply a correction for the wind on our OUTBOUND LEG. As we are performing a 180 degree turn the wind will now be from our RIGHT side and the correction we need to add is TWICE the ‘heading difference’ (2 x 5 degrees in this case) in the OPPOSITE DIRECTION from the direction you applied on your INBOUND LEG. This makes our corrected heading; 099 + 10 = 109 degrees.

Fly this heading for the one minute as the OUTBOUND leg then turn left again for the INBOUND TURN, and you should re-establish yourself inbound to the FIX on the LOC.

This method of applying wind correction works no matter what direction the wind is coming from relative to the aircraft. If you are correcting LEFT on the inbound leg then double the correction and apply it to the RIGHT on the OUTBOUND leg and vice-a-versa. If the correction is to the RIGHT on the inbound leg then double the correction and apply it to the LEFT on the OUTBOUND leg.

Important things to remember:-

• Very rarely will you get NO WIND conditions, so remember how to apply wind correction to the OUTBOUND leg.
• Establish yourself quickly on the INBOUND leg to find out what wind correction you have to apply.
• The only leg you actually time is the OUTBOUND LEG; you must start the clock as soon as you start the OUTBOUND LEG. You do time the INBOUND leg to ensure that it is somewhere around 1 min on the INBOUND leg, you use the FIX to determine when you start your turn OUTBOUND. If there is a substantial error on the INBOUND leg then time may be added to the OUTBOUND LEG.
• SPEED control is very important, you MUST fly a constant speed when in a hold, different speeds will mean that your turn radius will be different making it harder to establish your self on the INBOUND leg

On the next page, we look at the correct way to enter the holding pattern.

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Entering a Hold.

I have discussed how to fly a hold, now I will describe how to enter a hold. This is the most difficult part of hold flying and the part that confuses people the most.

There are three methods of entering a hold; the DIRECT ENTRY, the TEARDROP ENTRY, and the PARALLEL ENTRY.

The instructions from ATC to enter a hold will be something like this;

“Hold on the 270 Radial, west of the 15 DME fix from ABC VOR, standard pattern, 1 minute legs.”

The hold fix on the illustration below is shown as a BLACK TRIANGLE.

The first part “Hold on the 270 Radial west of the 15 DME fix from ABC VOR” tells us what radial we are to hold on. From this we can work out our INBOUND and OUTBOUND heading. As we are INBOUND on the 270 radial our INBOUND LEG HEADING will be 090 degrees and our OUTBOUND LEG HEADING will be 270 degrees.

ATC have also told us the position of the HOLDING FIX as “15 DME from the ABC VOR“, and that we must hold to the west of that fix. They also told us “standard pattern, 1 minute legs“. This means RIGHTHAND TURNS with a ONE MINUTE OUTBOUND LEG.

To enter the hold correctly we must determine what side of the hold you are entering from.

Here is the simple method that handles all hold entries.

Chop the holding pattern in half as shown (see the red line). 

If you are entering from the larger side, it is always a DIRECT ENTRY.

If you are entering the hold from the smaller side, chop the holding pattern between the protected side and the non-protected side (see the blue line below).   

If you are entering from a heading on the protected and smaller side, you always use a PARALLEL ENTRY.

If you are entering on the non-protected and on the thin side, it is always a TEARDROP ENTRY.

Next, we look in more detail at each entry type and how to execute the entry.

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What does each entry look like and how do we execute it? 

Normally, when holding at a fix like the example, you are usually flying on a radial from another VOR which will take you over the fix. Flying to a fix using one VOR is very difficult to achieve.

Direct Entry.

In this example, we are flying on a heading of 060 degrees directly to the fix on the larger side of the hold. As we cross over the hold fix, we execute a RIGHTHAND TURN to 270 degrees to position on our OUTBOUND LEG.

NOTE although we have flown over the fix we are not yet established in the hold until we pass over the fix again and turn onto the OUTBOUND LEG again.

Parallel Entry.

Entering from the smaller protected side, our in-bound heading in this example is approximately 330 degrees. After crossing the fix, we turn onto our OUTBOUND LEG HEADING and fly for one minute. We then execute a LEFTHAND TURN onto a heading to intercept our INBOUND LEG at an angle of about 40 degrees.

In this example, we would turn LEFT to a heading of 050 degrees and intercept the ABC VOR 270 Radial. Once we cross the fix, we then turn RIGHT to 270 degrees and start our timed OUTBOUND LEG.

Teardrop Entry.

Entering from the thin, non-protected side, the in-bound heading for this example is approximately 240 degrees. After crossing the fix we turn onto the heading of our OUTBOUND LEG minus 40 degrees for a RIGHT TURN HOLD, or our OUTBOUND LEG heading plus 40 degrees for a LEFT TURN HOLD. In this example, after crossing the fix we would set up a heading of 230 degrees and fly this heading for one minute. We then execute a RIGHT TURN to intercept our INBOUND LEG and establish the aircraft on the ABC VOR 270 Radial inbound (heading 090 degrees).

And that is basically how to fly holds.

Practice is the only way to get the hang of accurately entering and flying holds.

Just remember these basic rules:-

1. Establish as early as you can what type of ENTRY you need to perform and write down the headings you need to use.
2. The only part of the hold that is TIMED is the OUTBOUND LEG, when established in the hold it takes approximately 4 minutes to complete one pattern, but remember this can change if you have a large wind component.
3. DO NOT time the INBOUND leg. You use the FIX to determine when to start your turn OUTBOUND.
4. Very rarely will you get NO WIND conditions, so remember how to apply wind correction to the OUTBOUND leg.
5. Establish yourself quickly on the INBOUND leg to find out what wind correction you have to apply.
6. SPEED control is very important, you MUST fly a constant speed when in a hold. Changing speed will mean that your turn radius will be different making it harder to establish yourself on the INBOUND leg.
7. Use your AUTOPILOT. This is a valuable metod of control, so make use of it.

John Goodwin.