To start I would like to say I am using the ICAO standards here, each country may differ, so please consult your own countries rules and regulations.
First of all, what is a hold?
A hold in aviation is a procedure flown by an aircraft for a number of reason, but mainly to use up time. The procedure is normally in a racecourse pattern, using a particular point as a reference. A racecourse pattern is prefered to just cirlcling as it is more efficient (there are more forces and drag on the aircraft when turning). Through the rest of this post I will explain more on how to fly the Hold, what rules to follow and some useful tips to help you in the air.
Looking at the above picture you can get more of an idea of what a hold looks like. Refering to that picture above we will go through each point.
FIX – The fix is our reference point we want to use. Anything that does not move could be a FIX, to mention a few, it could be a VOR or NDB Beacon, a GPS location, a Radial and DME point or even a point on the ground.
INBOUND LEG – This is just the leg that you fly towards the FIX, there are rules about this that we will explain later in the post.
OUTBOUND END – The turn in your hold that is furthest away from the fix.
OUTBOUND LEG – This is just the leg that you fly away from the FIX
FIX END – The turn in your hold that is closest to the FIX.
ABEAM FIX – This is the point on your OUTBOUND LEG that you are 90˚ to the FIX and when you start your OUTBOUND LEG timing.
HOLDING SIDE – The side, of the imaginary line (red linein picture) that runs through the fix on the same track we fly the INBOUND LEG, we keep the plane when flying the hold.
NON-HOLDING SIDE – Opposite side of imaginary line we want to avoid flying in.
Now that we have a bit more of an idea of what a hold is, it would be good to go over the laws that govern a hold.
Direction – The STANDARD hold pattern is flown in a clockwise direction (turns to the right). There are cases when a hold is flown with turns to the left, this could be for a number of reasons. Turns are done at a rate 1 turn (10% of your speed + 7).
Timing – In order to keep flying the hold in the safe area, we use time on the inbound leg to keep it from getting too big. We start timing for the outbound leg when we are ABEAM the FIX. ICAO standard is:
14,000 Ft and below – 1 min on the inbound leg
14,001 ft and above – 1.5 min on the inbound leg
Speed – We have max speeds for particular altitudes, obviously you can fly below these speeds, but not above. Like the timing, this is to keep the aircraft flying in the safe area of the hold. ICAO standard is:
Up to 14000 ft: 230kts
14000 ft to 20000 ft: 240kts
20000 ft to 34000 ft: 265kts
Above 34000 ft: M0.83
Above is a picture of the 3 sectors we use to determine how we will fly the hold entry, this is used to make it easy for us to join the hold without any sharp turns, or the risk of leaving the safe area of the hold.
Which would you use?
For this example we will say our inbound track is 080˚. We choose the entry based on our headings. You also have a choice of which entry when you are within 5˚ of the sector boarder.
I – Paralelle Entry – The green sector, if we are coming from between 080˚ and 190˚, so our heading would be between 260˚ to 010˚.
II – Offset Entry (Teardrop Entry) – The blue sector, if we are coming from between 010˚ and 080˚, so our heading would be between 190˚ to 260˚.
III – Direct Entry – The red sector, if we are coming from between 190˚ and 010˚, so our heading would be between 010˚ to 190˚.
I – Paralelle Entry – Once overhead the FIX fly parallele to the inbound leg (in the opposite direction of the pattern) for 45 sec (or an appropriate amount of time) and then turning left (in a non-standard pattern you would turn right) and fly directly to the FIX and then continue the normal hold.
II – Offset Entry (Teardrop Entry) – Once overhead the FIX fly on a track which is 30˚ left of your outbound track (outbound track 170˚, then fly a track of 140˚) for 45 sec (or an appropriate amount of time), then turn right
(left in non-standard hold) and intercept the inbound track back to the FIX, continue with the hold.
III – Direct Entry – Once overhead the FIX turn right (left in non-standard hold) and continue with the hold.
Reasons to fly a hold:
It is part of an instrument approach.
Your are requested by ATC to hold, normally to allow time between traffic.
You need time to deal with a problem or just need time to configure the plane (remember never to rush yourself).
To wait your turn to land.
Tips and things to remember
When flying remember the wind! A rule of thumb is when flying inbound to the FIX take note of how many degrees you need to hold off for the wind to keep on the inbound track. Then on the the outbound leg hold off 3 times that amount. For example if you are holding of 5˚ into wind on the inbound, you need to hold off 15˚ into wind on the outbound leg. Also take into the account the headwind and tailwind on the indbound and outbound track, adjust your leg time as required to keep your inbonud leg 1 min (or 1.5 min)
The lastly the RULE OF THUMB.
This helps speed up your thinking when choosing a sector entry. The explanation will follow the picture.
When flying right hand patterns, hold your left hand up in front of the RMI/DG/HSI (left hand for standard hold, right hand for lnon-standard). Index finger pointing up to the lubber line (your inbound heading to the FIX) and thumb pointing about 70 degrees right of your present heading. Curl your remaining three fingers in a fist. Imagnine an extended center line from the tip of your thumb to the base of your thumb and extend the imaginary line to the other side of the RMI/DG/HSI to the heading that would be 110 degrees to the left of your current heading. You have now seperated the compass rose into three sections. From the lubber line to 70 degrees right will be teardrop entry. From the lubber line to 110 degrees left will be a parrallel entry. The 180 degrees below the line your thumb makes, will be a direct entry. Then what you have to look at is the OUTBOUND heading you will be flying in the holding pattern. Whichever sector the outbound heading falls into, is the type of entry you will make.
I hope this all helps in your studies and flying. It has helped me and the more I can share the better. Please if you have any questions please feel free to ask in the comment section below or contact me directly by email, Instagram or Facebook.
Feel free to have a look at other latest posts:
One of the best explanations of holding pattern I have seen. Thought about keeping a pdf file so we can use it as study guide? :p
Thanks so much, glad you enjoyed it and found it useful. I have thought about it, but also want to keep people visiting. I will think about adding something like that.