IFR Question
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IFR Question
I'm doing some study and can't find the answer to the following :
When can you divert off track to intercept the 60 sector of the initial approach to avoid doing the sector entry & holding pattern?
Any answers? A reference too if possible.
Thanks
O&G
When can you divert off track to intercept the 60 sector of the initial approach to avoid doing the sector entry & holding pattern?
Any answers? A reference too if possible.
Thanks
O&G
Thanks for asking this question! I have my MECIR initial test tomorrow and I went to type a response 10mins ago- but was only 75% sure of the answer. consulting Bob Tait's IREX book (pg 5.28 if you have it) the answer is as I thought-
When you are within 25nm and not below MSA you can manuevre as required to get inside the 60degree splay for initial approach track.
This one is 25nm and yet you can be out as far as 30nm to commence a visual approach- gotta love the different numbers.
It seems to me that IFR flying is something you only really understand when you are doing it- I read the Jepps and IREX book so many times but it was all gobbledegook until I started flying IFR.
When you are within 25nm and not below MSA you can manuevre as required to get inside the 60degree splay for initial approach track.
This one is 25nm and yet you can be out as far as 30nm to commence a visual approach- gotta love the different numbers.
It seems to me that IFR flying is something you only really understand when you are doing it- I read the Jepps and IREX book so many times but it was all gobbledegook until I started flying IFR.
Join Date: May 2006
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25nm vs 30nm visual approach
I think you will find that you can only conduct a visual approach when you are visual (as it suggests). The reason Tait states once within 25nm you can break off track to establish your inbound course is because 25nm MSA's are stated on the charts (not 30nm), therefore if you are in IMC you won't go flying into mountains 
When you live....
Try to think about what would be happening in the air.....
If IMC - no 1 priority is to stay 1000' above the terrain. How do you know where the terrain is? LSALT for the route safely gets you to the aid/point but only within the tracking tolernces of the route. If you're within 25nm of the destination you now have additional information about where the terrain is and so you have info on how to stay above it from the chart - this is the answer they're looking for and so 25nm will get you the marks.
Note that there are other ways of avoiding the terrain in practice. Some that come to mind are:
- be 'visual' in the sense that you can legally descend below LSALT (can't do that at night though). (Ignore 'Visual approach's' - they are a completely different kettle of fish - by definition you're not going to make the instrument approach.
- have another LSALT figure to work with - for example you can use the grid lowest safe to ensure that you won't hit any terrain within, say, 100nm of the destination (it may be a higher figure but you can still make it work)
I'm sure there are others but the other question is why would you want to start manouvering from more than 25nm out? At 180kts you're still 8 minutes from the aid and all you'll achieve is the adding of useless track miles.
One other trap to watch out for - if the airways LSALT is lower than the MSA (and it does happen - YMRY I think is an example) then if you're screaming in at LSALT trying to get visual and then want to manouvre inside 25nm then you must CLIMB to that MSA to ensure terrain clearance.
Very easy mistake to make.
Hope this helps,
UTR
If IMC - no 1 priority is to stay 1000' above the terrain. How do you know where the terrain is? LSALT for the route safely gets you to the aid/point but only within the tracking tolernces of the route. If you're within 25nm of the destination you now have additional information about where the terrain is and so you have info on how to stay above it from the chart - this is the answer they're looking for and so 25nm will get you the marks.
Note that there are other ways of avoiding the terrain in practice. Some that come to mind are:
- be 'visual' in the sense that you can legally descend below LSALT (can't do that at night though). (Ignore 'Visual approach's' - they are a completely different kettle of fish - by definition you're not going to make the instrument approach.
- have another LSALT figure to work with - for example you can use the grid lowest safe to ensure that you won't hit any terrain within, say, 100nm of the destination (it may be a higher figure but you can still make it work)
I'm sure there are others but the other question is why would you want to start manouvering from more than 25nm out? At 180kts you're still 8 minutes from the aid and all you'll achieve is the adding of useless track miles.
One other trap to watch out for - if the airways LSALT is lower than the MSA (and it does happen - YMRY I think is an example) then if you're screaming in at LSALT trying to get visual and then want to manouvre inside 25nm then you must CLIMB to that MSA to ensure terrain clearance.
Very easy mistake to make.
Hope this helps,
UTR
Last edited by UnderneathTheRadar; 19th Feb 2007 at 10:43. Reason: Brain fart - last section is about LSALT LOWER than MSA
