Minimum Procedural Seperation
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Minimum Procedural Seperation
Hope this is the right forum. I had a close call the other day in a west african UIR. No radar, non rvsm airspace. Ended up 3mile horizontal and 400' vertical at FL350. I filed an airprox and wondered what the minimum seperation i should have expected.
Thanks.
Thanks.
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Thanks, I was wondering about the lateral?
We had just been told to turn left to establish onto a certain radial whilst the other guy told to turn right and establish onto another. We were about 100mile from the vor inbound. Neither aircraft had commenced the turns when he came down 3 miles ahead of us.
We had just been told to turn left to establish onto a certain radial whilst the other guy told to turn right and establish onto another. We were about 100mile from the vor inbound. Neither aircraft had commenced the turns when he came down 3 miles ahead of us.
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The ICAO standard here would be 15 degrees VOR separation.
From the limited information in your post Im guessing you were both on-track to the same VOR with you following the other aircraft above you.
For vertical separation not to be required, you must both be established on radials differing by 15 degrees
If the other guy had been a little further ahead, on track DME could have been used to separate you with as little as 10 miles.
However, 15 degrees apart at 100 miles is a lot larger and would have taken quite some time to establish.
Depending on the state involved, there may be local provision for a reduced separation, as long as it is approved by ICAO, however, it sounds unlikely in this case that you could use any less than 15 degrees.
I think most of what Im saying is right, Im not a procedural airspace controller but this is from memory from the training school some time back!!
Cheers
From the limited information in your post Im guessing you were both on-track to the same VOR with you following the other aircraft above you.
For vertical separation not to be required, you must both be established on radials differing by 15 degrees
If the other guy had been a little further ahead, on track DME could have been used to separate you with as little as 10 miles.
However, 15 degrees apart at 100 miles is a lot larger and would have taken quite some time to establish.
Depending on the state involved, there may be local provision for a reduced separation, as long as it is approved by ICAO, however, it sounds unlikely in this case that you could use any less than 15 degrees.
I think most of what Im saying is right, Im not a procedural airspace controller but this is from memory from the training school some time back!!
Cheers
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AF1
Thanks , that's what i was looking for. Yes both inbound to vor, him above me same speed. The event happend prior to turning to establish so both on same headings.
Thanks , that's what i was looking for. Yes both inbound to vor, him above me same speed. The event happend prior to turning to establish so both on same headings.
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qcode, it's your comments that are a bit scary - as well as bigbird's experience. I know that young whippersnappers coming out of the college these days don't get procedural ratings but I though they were supposed to have an appreciation of the art.....but clearly I'm wrong!
bigbird, there are various separations that could have been used depending on the navaids available and the relative positions of the aircraft being separated. The UK rules are in the Manual of Air Traffic Services Part 1 - Section 1 Chapter 3. The ICAO rules, as I recall, are in PANS-ATM and the UK book pretty much replicates them. Hope this helps - in a non-radar environment it sounds like you were a bit close to the other aircraft.
bigbird, there are various separations that could have been used depending on the navaids available and the relative positions of the aircraft being separated. The UK rules are in the Manual of Air Traffic Services Part 1 - Section 1 Chapter 3. The ICAO rules, as I recall, are in PANS-ATM and the UK book pretty much replicates them. Hope this helps - in a non-radar environment it sounds like you were a bit close to the other aircraft.
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in a non-radar environment it sounds like you were a bit close to the other aircraft
If you were so close to the other guy the only procedural separation you could have would be 1000/2000 ft
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Thanks for all the input.
I filed an airprox because I was unhappy apout the seperation.
I wanted to find out more information about non radar seperation purely from a professional point of view. The more I know about your jobs the easier it is for us to work together. Bit like those experiance flights you may have taken, it all helps. I visited LATCC years ago, in the good old days, and came away with nothing but appreciation and admiration.
Spitoon
Thanks for the link, I found the section in the end.
I filed an airprox because I was unhappy apout the seperation.
I wanted to find out more information about non radar seperation purely from a professional point of view. The more I know about your jobs the easier it is for us to work together. Bit like those experiance flights you may have taken, it all helps. I visited LATCC years ago, in the good old days, and came away with nothing but appreciation and admiration.
Spitoon
Thanks for the link, I found the section in the end.
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15 degrees
Fruno
Are you sure about that?
As far as I can remember, the only stipulation for the 15 degree VOR separation is that
a. Both aircraft are established on a VOR radial
b. One aircraft is outside 15 dme (or is it 30?) from the VOR/DME station.
Dont ever remember anything about having to fly outbound. If that was true, how could you separate aircraft that were, for example, both 200 miles away from a VOR inbound ?
If you were concerned that one might infringe the 15 dme requirement, then simply, "climb/descend FLxxx, be level by 15 DME from the Ougadougoo VOR ..."
??
Cheers
AF1
Are you sure about that?
As far as I can remember, the only stipulation for the 15 degree VOR separation is that
a. Both aircraft are established on a VOR radial
b. One aircraft is outside 15 dme (or is it 30?) from the VOR/DME station.
Dont ever remember anything about having to fly outbound. If that was true, how could you separate aircraft that were, for example, both 200 miles away from a VOR inbound ?
If you were concerned that one might infringe the 15 dme requirement, then simply, "climb/descend FLxxx, be level by 15 DME from the Ougadougoo VOR ..."
??
Cheers
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Procedures for Air Navigation Services
Air Traffic Management (ICAO Doc 4444)
CHAPTER 5. SEPARATION METHODS AND MINIMA
5.4 HORIZONTAL SEPARATION
5.4.1.2 LATERAL SEPARATION CRITERIA AND MINIMA
5.4.1.2.1.2 By use of the same navigation aid or method.
By requiring aircraft to fly on specified tracks which are
separated by a minimum amount appropriate to the navigation
aid or method employed. Lateral separation between two
aircraft exists when:
a) VOR: both aircraft are established on radials diverging
by at least 15 degrees and at least one aircraft is at a
distance of 28 km (15 NM) or more from the facility
Air Traffic Management (ICAO Doc 4444)
CHAPTER 5. SEPARATION METHODS AND MINIMA
5.4 HORIZONTAL SEPARATION
5.4.1.2 LATERAL SEPARATION CRITERIA AND MINIMA
5.4.1.2.1.2 By use of the same navigation aid or method.
By requiring aircraft to fly on specified tracks which are
separated by a minimum amount appropriate to the navigation
aid or method employed. Lateral separation between two
aircraft exists when:
a) VOR: both aircraft are established on radials diverging
by at least 15 degrees and at least one aircraft is at a
distance of 28 km (15 NM) or more from the facility
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Oh, that raises another question; anyway I was taught to use this separation that way only. The drawing in my version of doc 4444 implies the "outbound" rule also.
My early days OJTI was kind enough to prove his view in a simulator room
My early days OJTI was kind enough to prove his view in a simulator room
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Can't preach about what should happen in deepest darkest, but in the Middle East we use the 15 degrees (established) 15 miles both ways to and from the VOR.
If my ever hazy memory is correct, that works out to be about 3.75nm between the two at 15 miles.
Back in Oz in the olden days, lateral separation was defined as 1nm between the possible positions of two or more aircraft.
So you build in all your tolerances and add 1nm to them...voila! safe!
Cheers
If my ever hazy memory is correct, that works out to be about 3.75nm between the two at 15 miles.
Back in Oz in the olden days, lateral separation was defined as 1nm between the possible positions of two or more aircraft.
So you build in all your tolerances and add 1nm to them...voila! safe!
Cheers
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It's been a good while since i learnt procedural as a method of control but if i remember correctly, min lateral separation is
45 degrees diverging from VOR (both outbound)
15 degrees with one aircraft outside 15miles (or 20DME to correct for slant angle at high levels)
On tracks that are separated by less than 15degrees you must have either timed or DME separation. Same track 20nm between provided no1 is 40kts faster. or 40DME at same speed.
Opposite direction closing must have vertical separation before within 40nm from each other, or can remove vertical restriction after passing each other +20nm (10nm each) or +10nm if within 100nm of VOR/DME station
Can't remember the timed rules. I'm a bit rusty on the same track 40kts rules.
Feel free to correct me.
BigBird,
In a Radar non-RVSM environment at FL350 you should expect at the very least 2000\' vertical separation or 5NM lateral.
Given that this was procedural, The minimum lateral separation should be 15degrees from the VOR at your range to station, but that only applies if both aircraft are established on radials. Vertical separation must be re-applied in order to take one aircraft off a radial (even if it\'s a diverging turn)
On same track (ie less than 15degrees diverging), both inbound, at same speeds then longitudinal separation standards must be applied. Thats the 40nm rule or 20nm if No1 is 40kts faster.
Long story short:
Basically you should have been separated by 2000\'
Failing that, you should expect 20nm/40nm longitudinal or 22.5nm lateral (15degrees @ 90nm - 1 in 60) as a minimum in a non-radar environment at your range to station.
45 degrees diverging from VOR (both outbound)
15 degrees with one aircraft outside 15miles (or 20DME to correct for slant angle at high levels)
On tracks that are separated by less than 15degrees you must have either timed or DME separation. Same track 20nm between provided no1 is 40kts faster. or 40DME at same speed.
Opposite direction closing must have vertical separation before within 40nm from each other, or can remove vertical restriction after passing each other +20nm (10nm each) or +10nm if within 100nm of VOR/DME station
Can't remember the timed rules. I'm a bit rusty on the same track 40kts rules.
Feel free to correct me.
BigBird,
In a Radar non-RVSM environment at FL350 you should expect at the very least 2000\' vertical separation or 5NM lateral.
Given that this was procedural, The minimum lateral separation should be 15degrees from the VOR at your range to station, but that only applies if both aircraft are established on radials. Vertical separation must be re-applied in order to take one aircraft off a radial (even if it\'s a diverging turn)
On same track (ie less than 15degrees diverging), both inbound, at same speeds then longitudinal separation standards must be applied. Thats the 40nm rule or 20nm if No1 is 40kts faster.
Long story short:
Basically you should have been separated by 2000\'
Failing that, you should expect 20nm/40nm longitudinal or 22.5nm lateral (15degrees @ 90nm - 1 in 60) as a minimum in a non-radar environment at your range to station.
