Wind Correction in the Hold
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Wind Correction in the Hold
Can someone shed some light on a good rule of thumb for wind correction in the hold? I have been told to use three times wind correction factor (WCF) whilst outbound but I have lost confidence since this never seems to work particularly well. Some texts I have come across advocate twice WCF outbound. I understand the rationale behind 3 x WCF but surely once this correction becomes largely you are changing your heading so much in relation to the wind that this rule of thumb becomes inaccurate. I have also been told that this rule should only be used up to 45 deg correction outbound. Again I have lost confidence in this as a rule since it has never worked particularly well for me and seems like a massive correction.
Grateful for any expert tips on WCFs and timing as well. If anyone has come across a good article on the web I would also be grateful for the URL (had a look using Google but not come across anything particularly useful so far). Many thanks.
Grateful for any expert tips on WCFs and timing as well. If anyone has come across a good article on the web I would also be grateful for the URL (had a look using Google but not come across anything particularly useful so far). Many thanks.
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I've seen more rules of thumb on this subject than I have fingers and toes! However, the one suggested to me when training goes like this:
Use 3xWCF on outbound leg unless the wind direction is within 30deg of the hold axis, in which case use 2xWCF.
Add/subtract 1 second per knot of headwind/tailwind to the outbound timing.
From a teaching view point, you can come up with endless extra rules that if applied when planning before flying, and given an accurate wind forecast and if flown accurately will give great results. How relevant this is to the real world when having to take up an unprepared hold whilst hand flying in IMC is a moot point.
After discussing these rules of thumb on holding with my IMC students I try to impress on them that maintaining situational awareness and flying the assigned altitude are the priorities.
Use 3xWCF on outbound leg unless the wind direction is within 30deg of the hold axis, in which case use 2xWCF.
Add/subtract 1 second per knot of headwind/tailwind to the outbound timing.
From a teaching view point, you can come up with endless extra rules that if applied when planning before flying, and given an accurate wind forecast and if flown accurately will give great results. How relevant this is to the real world when having to take up an unprepared hold whilst hand flying in IMC is a moot point.
After discussing these rules of thumb on holding with my IMC students I try to impress on them that maintaining situational awareness and flying the assigned altitude are the priorities.
For f's sake - just work out the max drift from the forecast W/V and apply the relevant factor. 3 times outbound is fine. Slow little things like Senecas probably need 10s per 10kt H/T timing correction, proper aeroplanes use 5s per 10kt and no-one bothers if the wind factor is <10kt.
It's better to over compensate than under compensate, because you can use the wind to your advantage to make good the inbound track to the beacon - ease off the bank as you roll out and let the wind help. But at the end of the day it's a non-precision event if based on a NDB.
If you've got 45deg applied, you've got a savage cross-wind in a 120KIAS aeroplane - about 30kts across! (30/2 = 15; 15x3=45). Could you actually land? If not, what are you doing poncing about in the hold?
I do wonder why so much importance is seemingly attached to this procedure from the stone age of aviation! And I say that as an IRE with 15 years of IRE'ing!
It's better to over compensate than under compensate, because you can use the wind to your advantage to make good the inbound track to the beacon - ease off the bank as you roll out and let the wind help. But at the end of the day it's a non-precision event if based on a NDB.
If you've got 45deg applied, you've got a savage cross-wind in a 120KIAS aeroplane - about 30kts across! (30/2 = 15; 15x3=45). Could you actually land? If not, what are you doing poncing about in the hold?
I do wonder why so much importance is seemingly attached to this procedure from the stone age of aviation! And I say that as an IRE with 15 years of IRE'ing!
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"wide and long and you can't be wrong." Just makes life easier on the base turn. Remeber it is only the inbound course that really matters. Don't get too bogged down in the semantics. What Beagle says is right, follow his advice and you won't go far wrong.
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Thanks for your input. Agree it's archaic but that's the way it is at the moment. Will give it a go next time.
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SAS has it right......aim to be slightly long and slightly wide when working on the outbound.
The UK CAA consider it acceptable for the turn inbound to be stopped wings level on an intercept heading to the inbound course.
Remember that if you are wide enough to have a short wings level leg during the inbound turn, you get rid of any ADF dip problems.
As for "poncing about in the hold" with a 30 Kt crosswind.........ever done an enroute hold or even a circling approach?
Regards,
DFC
The UK CAA consider it acceptable for the turn inbound to be stopped wings level on an intercept heading to the inbound course.
Remember that if you are wide enough to have a short wings level leg during the inbound turn, you get rid of any ADF dip problems.
As for "poncing about in the hold" with a 30 Kt crosswind.........ever done an enroute hold or even a circling approach?
Regards,
DFC
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Beagle
I do wonder why so much importance is seemingly attached to this procedure from the stone age of aviation! And I say that as an IRE with 15 years of IRE'ing!
Isn't it that in the IMC Rating the holds are supposed to be pre-planned on the ground, using the Met form 214, while in the IR you are supposed to work out the correction on the spot?
Precision surely does not need to be that accurate, because a faster plane will be tracking a larger pattern, so the airspace will be reserved laterally anyway.
I do wonder why so much importance is seemingly attached to this procedure from the stone age of aviation! And I say that as an IRE with 15 years of IRE'ing!
Isn't it that in the IMC Rating the holds are supposed to be pre-planned on the ground, using the Met form 214, while in the IR you are supposed to work out the correction on the spot?
Precision surely does not need to be that accurate, because a faster plane will be tracking a larger pattern, so the airspace will be reserved laterally anyway.
