Visual Separation
I say there boy
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Not necessarily according to ICAO and UK Mats (can't speak for Oz).
Either:
a) The controller has to have both aircraft in sight; or
b) The pilots of both aircraft report that they have each other in sight; or
c) The pilot of the following aircraft reports that he has the preceding one in sight.
Either:
a) The controller has to have both aircraft in sight; or
b) The pilots of both aircraft report that they have each other in sight; or
c) The pilot of the following aircraft reports that he has the preceding one in sight.
Thread Starter
Thanks Foghorn but without assigning visual separation to the pilot(s) can a controller in a non radar environment separate two aircraft when they are within the lateral conflict area but but both aircraft are not in sight?
eg departing aircraft turns onto track follwed on a diverging track of, say 15 degrees, and provided the first is seen to establish on track and the second turn onto track are the aircraft deemed to be visually separated even though they may still be within the lateral conflict area
eg departing aircraft turns onto track follwed on a diverging track of, say 15 degrees, and provided the first is seen to establish on track and the second turn onto track are the aircraft deemed to be visually separated even though they may still be within the lateral conflict area
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The US works just as foghorn says, too. In order to apply visual separation, the tower controller must retain both aircraft in sight until another form of separation is achieved. This is most frequently done when applying non-radar separation between successive departures, when the heading given to the second aircraft passes though, or "turns inside" the first aircraft's heading. The tower controller can provide visual separation until both aircraft are established on their diverging headings. This obviously precludes the use of visual separation in this situation when there are low ceilings or restrictions to visibility.
The bottom line is yes, the controller must have both aircraft in sight.
The bottom line is yes, the controller must have both aircraft in sight.
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There are other types of separation though:
I tend to use frequency separation and window pane separation a lot, and if things get really bad, there's always 'visual on the radar screen' separation.
And of course if that still doesn't look good, you can use the emergency 'zoom in the radar picture' emergency method of increasing separation.....
I tend to use frequency separation and window pane separation a lot, and if things get really bad, there's always 'visual on the radar screen' separation.
And of course if that still doesn't look good, you can use the emergency 'zoom in the radar picture' emergency method of increasing separation.....
Thread Starter
Thanks for your invaluable comments. It's just that here in OZ there is a discussion going on and some senior (supposedly experts) are suggesting that they can separate on "projected flightpath" ie if I see one aircraft establish itself on, what I perceive to be, it's outbound track and I clear a subsequent departure aircraft on a diverging track (by say 20 degrees) then even if the aircraft are not in view and still inside the lateral separation point, then they are separated. This is because the controller predicts that on their "projected flightpaths" they will not be in conflict.
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YY,
Holy snapping duck sh!t batman.
How does the controller do that exactly? How is the "projected path established"? When the cloud base is... turning toward track is not established on... Maybe if the pilot report on the appropriate radial and you've still got eye's on him then fair enough, but turning right to intercept, one asumes there will be a left turn to pick up the track; if pilot goes through when turning left what have you then; a bad prediction? It probably falls into the can't hit in a pink fit standard, but I can't remember reading that standard in Doc4444 or MATS or AIP.
Maybe we could apply it to RNAV standards, I project I've got 30 RNAV because they are 6 mins apart, so I won't bother asking; Hey they are six minutes apart afterall.
I'm taking it you're talking depart non-radar tower like AY? Sounds like a cop out from actually separating aeroplanes. I know, intsall a radar near by, cut the tower airspace off at A045 call the bit above Class E and let the centre controllers do it. I know, I know!
Holy snapping duck sh!t batman.
How does the controller do that exactly? How is the "projected path established"? When the cloud base is... turning toward track is not established on... Maybe if the pilot report on the appropriate radial and you've still got eye's on him then fair enough, but turning right to intercept, one asumes there will be a left turn to pick up the track; if pilot goes through when turning left what have you then; a bad prediction? It probably falls into the can't hit in a pink fit standard, but I can't remember reading that standard in Doc4444 or MATS or AIP.
Maybe we could apply it to RNAV standards, I project I've got 30 RNAV because they are 6 mins apart, so I won't bother asking; Hey they are six minutes apart afterall.
I'm taking it you're talking depart non-radar tower like AY? Sounds like a cop out from actually separating aeroplanes. I know, intsall a radar near by, cut the tower airspace off at A045 call the bit above Class E and let the centre controllers do it. I know, I know!
I'm not comfortable in "letting them go" until i've sighted both aircraft and they are diverging. Things can get a little tight when running this with two outbound aircraft, and the way i read it is that you have to have them visual until the latsep, which for 20 degrees is 11nm. This is assuming the pilot hasn't accepted own separation..
I may be reading into things here, and this very same thing happened at YMAY not long ago, but it was 13 (yes, 13) degrees
and they claim it was visually separated.. how the f can you see them to the latsep of 27 nm? unless they were big a/c (which they were not).
I may be reading into things here, and this very same thing happened at YMAY not long ago, but it was 13 (yes, 13) degrees
and they claim it was visually separated.. how the f can you see them to the latsep of 27 nm? unless they were big a/c (which they were not).
Thread Starter
The supposed experts are pushing to have MATS "clarified" so that MATS 4.5.2.2 "Aerodrome controllers may also separate by the use of visual observation of aircraft position and projected flight paths" is interpreted to mean:- "If I see to aircraft diverging away from each other and they subsequently are lost from view, then they are separated because I projected (anticipated) that they will achieve procedural separation at some point, regardless of whether or not they were procedurally separated when I lost sight of them"
From my reading the procedure indicates "visual observation of aircraft position AND projected flight paths" meaning you MUST be able to see the aircraft AND (meaning at the same time not or or either) the controller anticipates the flightpaths will diverge such that an unsafe situation does not develop.
From my reading the procedure indicates "visual observation of aircraft position AND projected flight paths" meaning you MUST be able to see the aircraft AND (meaning at the same time not or or either) the controller anticipates the flightpaths will diverge such that an unsafe situation does not develop.
Thread Starter
fixa24 In the incident at AY written up recently in the Safety Mag the controller had 12 degrees (lat sep of 41DME) and claimed he had "visual separation" now work that one out!!
Visual Separation
Thanks yarrayarra.. i knew it was a little skinny
UNLESS the aircraft is a C5 or something of the type, then i don't know how he (or she) expected to see them at 41nm.. if they couldn't then really, what did they have? All good and well having this "projected flight path" crap, but how many times you seen someone help themselves a littl left and right of track without telling you? heaps in a procedural environment. Then what have you got?
UNLESS the aircraft is a C5 or something of the type, then i don't know how he (or she) expected to see them at 41nm.. if they couldn't then really, what did they have? All good and well having this "projected flight path" crap, but how many times you seen someone help themselves a littl left and right of track without telling you? heaps in a procedural environment.
Then what have you got?
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Originally Posted by fixa24
......but how many times you seen someone help themselves a littl left and right of track without telling you? heaps in a procedural environment. Then what have you got?
Then what have you got? (bursts into tears.......!)
Thread Starter
Yep, I find it astounding but due to "streaming" and the old 3 degrees of separation from one generation to the next, we now have the situation where newer tower controllers at non radar towers are being taught 90 percent of sweet f.....all.
The way I see it in a non radar environment
To me there are separation standards namely:
-Vertical
-Lateral
-Longitudinal
-Visual by the controller
-Assignment of visual separation to the pilot
and indeed separation only exists when at least one of these standards is in place between aircraft at any moment.
The basis on which lateral separation points are calculated takes into account all the variables associated with the accuracy of an aircraft's tracking ( see tolerances in MATS) :
• Equipment error
• Pilot tracking tolerance
• Slant range error
• Navaid tolerances (eg scalloping of an VOR)
• Navaid range
• etc
When applying visual separation between aircraft within the area of conflict the controller is taking responsibility for the separation, and these tolerances do not come into consideration as the controller will observe the aircrafts' flightpaths and notice any deviation. Once either or both of the aircraft being separated are not in sight all bets are off because any deviation cannot be monitored and hence the applicable tolerances immediately come into consideration and need to be applied. If another separation standard is not established before the aircraft are lost from sight, there is an instantaneous BOS.
It was also forcefully presented to me by the "experts" that not only may the controller have just one aircraft in sight but indeed it was possible to have both aircraft out of sight and considered separated with no other standard in place. This was achieved in anticipation that the controller would sight an arriving aircraft in a position which is nowhere near where the departing aircraft was last seen! I found this astounding!
Ah ignorance is bliss!!
The way I see it in a non radar environment
To me there are separation standards namely:
-Vertical
-Lateral
-Longitudinal
-Visual by the controller
-Assignment of visual separation to the pilot
and indeed separation only exists when at least one of these standards is in place between aircraft at any moment.
The basis on which lateral separation points are calculated takes into account all the variables associated with the accuracy of an aircraft's tracking ( see tolerances in MATS) :
• Equipment error
• Pilot tracking tolerance
• Slant range error
• Navaid tolerances (eg scalloping of an VOR)
• Navaid range
• etc
When applying visual separation between aircraft within the area of conflict the controller is taking responsibility for the separation, and these tolerances do not come into consideration as the controller will observe the aircrafts' flightpaths and notice any deviation. Once either or both of the aircraft being separated are not in sight all bets are off because any deviation cannot be monitored and hence the applicable tolerances immediately come into consideration and need to be applied. If another separation standard is not established before the aircraft are lost from sight, there is an instantaneous BOS.
It was also forcefully presented to me by the "experts" that not only may the controller have just one aircraft in sight but indeed it was possible to have both aircraft out of sight and considered separated with no other standard in place. This was achieved in anticipation that the controller would sight an arriving aircraft in a position which is nowhere near where the departing aircraft was last seen! I found this astounding!
Ah ignorance is bliss!!
Thread Starter
What is being claimed is that MATS 4.5.2.2 "Aerodrome controllers may also separate by the use of visual observation of aircraft position and projected flight paths" is a separation standard of it's own rather than a procedure.
MATS 4.5.2.5 states: "ATC shall maintain, as far as possible, a continuous visual watch to detect and determine the position, and ensure the safety of, aircraft."
As both MATS 4.5.2.5 and MATS 4.5.2.2 are in the same section of MATS under "Separation Using Visual Observation" I don't see how any controller can justify in any way the application of visual separation without both aircraft being in sight.
MATS 4.5.2.5 states: "ATC shall maintain, as far as possible, a continuous visual watch to detect and determine the position, and ensure the safety of, aircraft."
As both MATS 4.5.2.5 and MATS 4.5.2.2 are in the same section of MATS under "Separation Using Visual Observation" I don't see how any controller can justify in any way the application of visual separation without both aircraft being in sight.
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Im with you. But the Kiwi's use the same idea. Its called Composite visual over here! Mind you they apply it when separating VFR from IFR in class D CTR's!! Go figure?? In their defence they call it segregation not separation, as there is no requirement to prove a standard in Class D between VFR /IFR. What do the boys in blue think on this one ?? !
Thread Starter
Yeah that's here in OZ too in Class D towers ( up to A045) with separation by issuing traffic between IFR and VFR. But there's also a whole new discussion on IFR separating each other in any airspace too, but that involves our magnificent NAS
Don't have a problem with that. The issue I'm trying to get fixed is the "anticipated visual" or "anticipated visual" until the other controller gets "anticipated separation" by "anticipated procedural" or anticipated radar"
To put it bluntly the "can't hit in a fit" standard
Don't have a problem with that. The issue I'm trying to get fixed is the "anticipated visual" or "anticipated visual" until the other controller gets "anticipated separation" by "anticipated procedural" or anticipated radar"
To put it bluntly the "can't hit in a fit" standard
What i've found is it is mainly the older controllers using this "projected flight path" caper. sure there not gonna hit, but what have you really got when it comes down to it?
I've tried it a few times, and i do use it in VMC. I do not like and would never use it in IMC but have seen it done, once the aircraft is airborne and appears to be on its outbound track before you lose sight of it. In VMC i'm fine with it, i can watch the A/C to the latsep, get a distance report, then roberts your fathers brother.
I agree it is dodgy. People who don't really understand FULLY what they are trying to achieve, and maybe these people OJTI another the same habits. Is it just laziness? how hard is a step climb/descent? How much is your licence worth? Yes these controllers are moving the planes apparently quicker, but whats the cost when it goes wrong? and one day it will...
I have heard that they are going to change the wording in MATS so this kinda stuff is legal.. I think i'll still do things the same way as i do now thanks..
I've tried it a few times, and i do use it in VMC. I do not like and would never use it in IMC but have seen it done, once the aircraft is airborne and appears to be on its outbound track before you lose sight of it. In VMC i'm fine with it, i can watch the A/C to the latsep, get a distance report, then roberts your fathers brother.
I agree it is dodgy. People who don't really understand FULLY what they are trying to achieve, and maybe these people OJTI another the same habits. Is it just laziness? how hard is a step climb/descent? How much is your licence worth? Yes these controllers are moving the planes apparently quicker, but whats the cost when it goes wrong? and one day it will...
I have heard that they are going to change the wording in MATS so this kinda stuff is legal..
I think i'll still do things the same way as i do now thanks..