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Radar vectoring below MSA

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Radar vectoring below MSA

Old 6th Oct 2020, 17:58
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Radar vectoring below MSA

Hello,

I've been told recently that if you get a direct routing to a fix below the MSA, for example to cut a missed approach procedure short, and just divert to somewhere else, then you need to confirm that you are being radar vectored? This sounds odd to me, as PANS-ATM defines vectoring as such:

Vectoring. Provision of navigational guidance to aircraft in the form of specific headings, based on the use of an ATS surveillance system.

The way that I read the above, is that the only way to be vectored is by giving a heading, and therefore if given direct a VOR, it is not a vector.
I also digged a bit further, and found this in PANS-ATM:

8.6.5.2 When vectoring an IFR flight and when giving an IFR flight a direct routing which takes the aircraft off an ATS route, the controller shall issue clearances such that the prescribed obstacle clearance will exist at all times until the aircraft reaches the point where the pilot will resume own navigation. When necessary, the relevant minimum vectoring altitude shall include a correction for low temperature effect.

Would this mean if given a direct routing, the ATCO will always make sure there is sufficient obstacle clearence? Are there any exceptions?
Thanks in advance!
KongFlyer is offline  
Old 7th Oct 2020, 04:39
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Originally Posted by KongFlyer View Post
Hello,
Would this mean if given a direct routing, the ATCO will always make sure there is sufficient obstacle clearence? Are there any exceptions?
Thanks in advance!
Yes, the controller is responsible for terrain clearance in this situation - using the Radar Terrain Clearance Chart (or whatever it is called in your neck of the woods). The exception is to add the word VISUAL to the clearance (only if the pilot has reported visual). The terrain separation then becomes pilot's responsibility.
Have had occasions where the pilot required diversion due thunderstorm while still below radar terrain clearance level - advised pilot of radar terrain level, if they still require turn, then advise them that: on emergency basis turn is at pilot's discretion - submit incident report.
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Old 7th Oct 2020, 06:31
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In the UK, all IFR airports with radar are required to have a Surveillance Minimum Altitude Chart (SMAC), (previously known as a Radar Vectoring Area (RVA) Chart) covering the area around the airport which indicates to controllers where they may vector traffic below the MSA and still provide a minimum of 1,000ft above terrain, reducing to 500ft in the final approach area.
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Old 7th Oct 2020, 07:28
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But all that doesn't prevent a controller from making a mistake. Thus the wise pilot will check the MSA against his company charts and either accept or reject the clearance on that basis. Many years ago, before the advent of nav displays with moving maps and magenta lines, I found it necessary to argue with a controller and reject his clearance. I'm glad I did.
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Old 7th Oct 2020, 08:11
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Originally Posted by Bergerie1 View Post
But all that doesn't prevent a controller from making a mistake. Thus the wise pilot will check the MSA against his company charts and either accept or reject the clearance on that basis. Many years ago, before the advent of nav displays with moving maps and magenta lines, I found it necessary to argue with a controller and reject his clearance. I'm glad I did.
Controllers don't make mistakes.
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Old 26th Oct 2020, 14:27
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We have a pretty high MSA, 5200 feet above the airport level (which is at sea level), and an MVA 3900 feet above the airport level. We do correct the MVA for both temperature and high wind - 35 celcius is not uncommon here in wintertime.

The general concensus is that on departure the pilot in command has the responsibility for terrain separation until the MSA is reached, or, if identified on radar, the MVA. Same during approach when below MSA/MVA. So we don't ever directly touch an IFR flight below those levels.

What we do though is using the phrase "At safe altitude....." when the weather is so that we can assume the pilot is IMC during climb, or in good weather "When ready....", to keep the pilots attention to the fact he is responsible for separation to terrain, but he can always turn earlier if he wants to. And depending on our feeling of how well the pilot knows the area we may include the "Safe altitude is 5300 feet...."

When our radar dies during winter, it gets a little more "fun", cause then pilots are supposed to make the temparature correction to the MSA themselves.... and it goes a little like "Descend to 5300 feet...." and a little while later "What altitude are you descending to?" <-- that's a little tricky, but we usually figure it out and normally they know they're on their own (since we advice them the radar is out).

EDIT: Keep in mind the chapter you're referring to is "Surveillance Service", so it'll ONLY be in force at the moment we say "identified" to an aircraft..... until then, you're not using that chapter.
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