Holding Patterns

[Eskimo]

Is there any point in any type of flying (VFR, IFR ect) when ATC gives you holding pattern instructions, because I think it would be interesting to do for a while.
Thanks

[RollerBall]

Not to my knowledge. You'll need to get hold of some plates and set them up yourself.

For example, I've included plates for Kai Tak rwys 13 and 31 with the scenery which show you the holding points and patterns for both.

Let's say you approach for a landing on 13 from the north at 15000 ft. Now you'll need to cancel IFR because otherwise they'll bring you in for a direct approach not on the IGS. So you descend to say 10000 and enter the hold over Cheung Chau (CH 112.3). You descend in the hold to 8000 or to a min of 6000. Then you exit the hold on 270 from CH to hit 6000 ft at waypoint Golf when you commence your descending turn onto 045 to intercept the IGS (88 deg) at 4500ft.

Then you follow the normal IGS procedures.

When I get some time (!) I'm going to look at creating the IGS approach using the new XML SDK because I saw on a forum somewhwre that somebody had already more or less done it. But in any case you can do the above very well yourself. It's great fun and needs a bit of practise to get right. Then you can go on to do 31...

Roger

[krazyj]

speaking of holding patterns

I've tried the lessons and I find it hard to know when excatly to turn and how much ??

any advice on this ?

thanx

[Billerator]

A standard holding pattern:

The 'inbound' leg (this is when you are approaching the VOR on the specified heading) lasts all the way until your VOR1 display turns off or shows the barber pole.

When you are directly over the VOR, you should turn (normally at 45

[iVIPER21]

Billerator is close with his instructions, however:

turns in a standard holding pattern are made to the right (unless otherwise assigned by ATC) at standard rate (3 degrees per second). thus, a 180 degree turn will take you one minute. followed by one minute on the outbound leg. then another standard rate 180 degree turn should place you on the correct radial from the VOR. then another minute on the inbound leg to the VOR. so one circuit in the holding pattern should take you 4 minutes. this is also assuming no wind. you will have to make adjustments to your timing as necessary for wind.

that might be too much info for what you are looking to do but it is the correct way to fly a holding pattern. you should also look up some info as to holding pattern entries (direct, teardrop and parallel) and when to use each one.

finally, if you really want some realism, start at the assigned altitude and work your way down after each circuit to simulate the "stack" as if there were other planes in the holding pattern. you would descend as each "imaginary" plane was cleared to exit the holding pattern and continue to land.

[Billerator]

Thanks for correcting me Viper, I wasnt too sure about it.

What are the vertical spacings in stacks, do you know?

[iVIPER21]

Billerator:

i believe the common practice ATC uses is 1,000 ft spacing in the stacks. also, here is more pertinent info about holding patterns:

bank angle:
3 degrees per second
or
30 degree bank angle
or
25 degree bank angle if a flight director system is being used.

maximum holding speeds for civil aircraft:
-at 6,000 ft MSL and below: 200 KIAS
-at 6,001 ft MSL to 14,000 ft MSL: 230 KIAS
-above 14,001 ft MSL: 265 KIAS

also, because military aircraft fly at higher speeds than civil aircraft, the speed limitations are raised at military airfields.  at USAF fields, the max holding speed is 310 KIAS and at NAS fields the max is 230 KIAS (unless otherwise published).

it should be noted that above 14,000 ft MSL the inbound and outbound legs are flown for 1.5 minutes so that one circuit takes 5 minutes to complete.

finally, ATC and pilots use holding patterns as last resorts. Usually, if there is heavy traffic going into a certain airport, ATC's Central Flow Control will not allow a flight still on the ground that is going to the overly congested airport to takeoff. Airlines hate putting planes in holding patterns as well because of the extra jet fuel it burns, time delays and passenger connection conflicts, etc all of which costs them $$$. Think about it... when was the last time you were on a commercial flight and were in a holding pattern? ok and when was the last time your flight was delayed because of weather or congestion not at the airport you are departing from but rather the airport of your destination?  ::)

i'll post a couple diagrams explaining holding pattern entries in a little bit with a couple of examples of typical ATC holding instructions.  ;)

[iVIPER21]

ok school is in session, lol.

Holding Patterns 101:
how to draw a holding pattern and determine what type of entry you should use.

(the following example will be shown using left hand turns. it should be noted that the standard direction of turn is actually to the right unless ATC's clearance calls for left hand turns or a pilot requests left hand turns and ATC approves.)

example clearance from ATC:
"Cessna 1234A, hold west of the XYZ VOR, maintain 2000, left turns, expect further clearance at 22 past the hour."



in this case, we are to hold west of the VOR which will be the 270 radial from the station. so first draw the inbound leg (the 270 radial from the station) then the rest of the holding pattern.








the direct entries will be the two quadrants on the same side as the 70 degree angle. the teardrop will be opposite the 70 degree angle and the smaller slice. the parallel will be opposite the 70 degree angle and the larger slice.



this will tell you what radial from the station you are on and will allow you to draw a line of position from the VOR to your aircraft. in this example, we will say that we are on the 045 radial from the station (assuming that the top of the image is magnetic north).



here is what it would look like if it were right hand turns:


here are what the different entries would look like coming from each quadrant and then flying to the VOR and so on...

Direct #1


Direct #2

[iVIPER21]

Teardrop


Parallel


A variation on the Parallel entry


finally, as you fly over the VOR during the last part of your entry, the TO/FROM flag will change. at this time, start your standard rate turn, start your timer and then turn the OBS knob to the 090 radial with a TO indication.

if anyone thinks there should be any changes to this, feel free to let me know. the only real way to learn holding patterns is to practice making up clearances and then drawing the patterns over and over again. do NOT use shortcuts because 9 times out of 10 they will screw you up if ATC gives you left hand turns. hope this helps anyone who has been intimidated or frustrated by holding patterns!  ;D

[Billerator]

Lol, some nice info there Viper, thnx.

I dont see why entering the hold is so annoying for pilots, I find it quite easy.

[garymbuska]

think of it this way holding patterns for pilots is the same thing as a line at a check out register.
In other words something you really do not want to do but have no choice.

[birdie]

Very very good job of explaining the VOR hold by viper!  Here is the rest you need to know about holds.  It is the Canadian regulations but I think they are very close if not the same to the USA.  Cheers!

[iVIPER21]

Billerator:

i believe the common practice ATC uses is 1,000 ft spacing in the stacks...

ATC currently uses 1000 ft spacing for non-jet aircraft and 2000 ft spacing for jet aircraft. however, they are in the process of changing the jet spacing to 1000 ft, requiring very very sensitive altimeters aboard jets to help eliminate the possibility of a mid air in the stack.