Visual Separation Page: 7 of 13

Stagformation
February 06, 2025, 16:55:00 GMT
permalink Post: 11823104

Quote:

Originally Posted by galaxy flyer

It bit of mystery why the Army was so quick to request visual separation, but I’d guess it’s “Pavlovian”

Very unlikely the helo crew could actually identify the right traffic 7nm away in half a second. My guess is they instantly say, ‘traffic in sight, request visual separation’, because they know that any other response (inferring traffic not in sight) obliges ATC to apply minimum 500ft/1.5mi separation in class B airspace and then a whole can of worms ensues. No other option available to the controller as far as I can see.

Ref para 3.2.3. e. 2 here https://www.faa.gov/air_traffic/publ...l%20separation .

Subjects ATC Separation (ALL) Traffic in Sight Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

8 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

galaxy flyer
February 06, 2025, 19:52:00 GMT
permalink Post: 11823184

Quote:

Originally Posted by Stagformation

Very unlikely the helo crew could actually identify the right traffic 7nm away in half a second. My guess is they instantly say, \x91traffic in sight, request visual separation\x92, because they know that any other response (inferring traffic not in sight) obliges ATC to apply minimum 500ft/1.5mi separation in class B airspace and then a whole can of worms ensues. No other option available to the controller as far as I can see.

Ref para 3.2.3. e. 2 here https://www.faa.gov/air_traffic/publ...l%20separation .

I agree, requesting visual separation was a means of \x93moving the mission\x94. Not doing so would create a real problem, probably delays, turnbacks, etc. \x93We can do that, we\x92re Priority Air Transport, says so right in the call sign\x94. It\x92s pretty simple because, in the dark, at low altitude, no one can positively identify one plane, by specific type, at 7 miles. No one is that good.

Subjects ATC Separation (ALL) Traffic in Sight Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

artee
February 06, 2025, 23:43:00 GMT
permalink Post: 11823316

Quote:

Originally Posted by Chesty Morgan

Yeah, but they can because they're cool and good and better than the rest of us and stuff....

It would be interesting to know what percentage of time the military helos request (and presumably get) Visual Separation.

Last edited by artee; 7th February 2025 at 00:21 . Reason: Changed VFR to Visual Separation.

Subjects Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

DIBO
February 07, 2025, 00:03:00 GMT
permalink Post: 11823326

Quote:

Originally Posted by artee

It would be interesting to know what percentage of time the military helos request (and presumably get) VFR.

... "request Visual Separation", not VFR (helicopter routes can only be flown VFR)
I wouldn't be surprised it's a high percentage of the Heli route1 & 4 traffic that requests "Visual Separation".

Have been listening to a few of LiveATC recordings. On the recording combining TWR & Heli frequencies, you can hear all transmissions (which sometimes overlap), however overall quality is poor. Nevertheless, I get the impression "request Visual Separation" is a common thing.
On the recording of the TWR VHF-frequency only, quality is good, but you don't get the requests/replies from the Heli's, so it's not always clear what was being requested/approved.

Subjects Separation (ALL) VFR Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

galaxy flyer
February 07, 2025, 00:09:00 GMT
permalink Post: 11823328

Quote:

Originally Posted by Chesty Morgan

Yeah, but they can because they're cool and good and better than the rest of us and stuff....

IFR separation is not appropriate for VFR traffic. Class B airspace has specific rules for separation of VFR/VFR and VFR/IFR aircraft. The helicopter routes do not appear designed to provide the required separation for VFR helicopters, at least where Route 4 and RWY 33 final approach cross each other. Was the design at fault OR was the daily application at fault? If the design was at fault, it\x92s an FAA DOD problem. I find it hard to believe the FAA didn\x92t address the correct separation distances in the design phase\x97it\x92s pretty clear. The FAA may have planned crossing traffic wouldn\x92t happen or there\x92s a FAA LOA defining how crossing traffic would be controlled, but the FAA didn\x92t say \x93okay, let\x92s go with 150\x92 vertically\x94.

Did the FAA or the Army assume they would always be able to apply visual (NOT VFR) separation. Visual separation does not necessarily mean 500\x92 vertically and 1.5 nm or radar target separation; it means \x93I see you, I miss you\x94. Did the operating plan always direct crews to use visual separation as the default plan? I hope not, but it is only I see it being written.

Subjects FAA IFR Radar Route 4 Separation (ALL) VFR Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

island_airphoto
February 07, 2025, 02:15:00 GMT
permalink Post: 11823361

Conflating VFR and Visual Separation is driving me nuts. Is this an EU thing?
You can be VFR in the Class B and treated exactly like an IFR flight. The clearance requirement from clouds VFR is just "clear of" clouds. You can have clouds three inches over you and five inches under you with each wingtip 3 inches away from them and still be VFR. This is much reduced from C, D, and E because you are under positive control. The helo was let loose to provide their own visual separation, which is a totally separate thing.

Subjects IFR Separation (ALL) VFR Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

51bravo
February 07, 2025, 11:55:00 GMT
permalink Post: 11823592

Quote:

Originally Posted by paulross

The original NYT article thanks to the Internet Archive (archive.org) .

Thanks for the picture. So three possible light blobs very close together AA5307 (short of landing), AA5342 (the CRJ), AA3130 (which was picked by PAl25 as conflict)

Regarding to the Pavlovian - if PAL25 wouldnt have requested 'visual separation', what "punishment" would they expect from the Tower? Orbit(s)? Vectors? Or somethin wild, considering 200/300' altitude limits along the river and buildings/infrastructure left and right (what diameter would an orbit cost with a Blackhawk, is it feasible over black water at 200')? Therefore I am asking - would a non-request of a 'visual separation' mean major complications to such a helicopter at night? That as well would then be a significant flaw in the design.

Subjects AA5342 Blackhawk (H-60) CRJ New York Times Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

Someone Somewhere
February 07, 2025, 12:05:00 GMT
permalink Post: 11823605

Quote:

Originally Posted by 51bravo

I believe visual separation from other aircraft is a very different scenario to visual separation from ground obstacles (VFR).

Waiting for the tower to have no aircraft below ~700ft in the approach area, if we're assuming a 1.5Nm separation, could be quite a while.

Subjects AA5342 Blackhawk (H-60) CRJ Separation (ALL) VFR Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

51bravo
February 07, 2025, 13:24:00 GMT
permalink Post: 11823651

"wait" , for sure.
How? considering where they have been at the first briefing about the conflict, just about entering Washington Channel ?

I have learned here:

speed around 90kt min, when orbiting
hovering not a safe option at night over black water (despite lights left and right and everywhere else)
Washington Channel: 200 yards wide
plus golf course and Potomac: less 1 mile wide
runway ends 01 and 15
city to the left with stadions etc.

I really run out of an idea what ATC would clear if the PAT25 crew didnt ask for "visual separation"...

Last edited by 51bravo; 7th February 2025 at 13:42 .

Subjects ATC PAT25 Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

Luc Lion
February 07, 2025, 14:19:00 GMT
permalink Post: 11823680

Quote:

Originally Posted by 51bravo

I really run out of an idea what ATC would clear if the PAT25 crew didnt ask for "visual separation"...

Maybe something like continue route RT1 up to Pennsylvania Avenue, then route RT2 to Woods Corner, then route RT3 to Wilson Bridge.
There is also route RT6 from Bolling to Woods Corner, but I don't think that the steep climb from Hains Point 200ft to Bolling 1400ft is reasonable.

Subjects ATC PAT25 Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

West Coast
February 07, 2025, 19:13:00 GMT
permalink Post: 11823870

Quote:

Originally Posted by Someone Somewhere

I'm honestly not certain, but if you're not visually separated , that seems to be the conclusion reached upthread and from the link I posted.

The guiding document in the US is the controller handbook, FAA order 7110.65AA. There, it is clear that visual separation is an approved form of separation in Class B airspace. Not defending the application of it specific to this crash, just pointing it out so the discussion revolves around existing FAA separation standards and not what folks in the thread wish it to be, believe it to be or what it is in their country.

Subjects ATC FAA Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

Stagformation
February 07, 2025, 21:23:00 GMT
permalink Post: 11823937

Quote:

Originally Posted by West Coast

To be specific, para 7.9.4b of the handbook, here:
https://www.faa.gov/documentLibrary/...5-24_READY.pdf

As mentioned upthread, if not visually separated then either 500ft or 1.5mi applies.

Correct if this is all wrong, but in the accident sequence if the helo had responded ‘not visual yet, looking’ or words to that effect, then presumably a controller could allow the two to get a bit closer and then advise the conflicting traffic info to the helo again, say at 2.5mi. If helo visual, great —maintain visual separation, responsibly passes to helo.

This is what happened, although the very busy controller failed to re-state the position of the CRJ to direct the eyes of the helo crew onto the CRJ in order that they could actually see and avoid it.

However if not visual at say 2.5mi, well it’s a bit late, but the controller does still retain responsibility for separation and must apply the 500ft/1.5mi standard. Presumably instant vectors away while simultaneously climb to min vectoring altitude. Or the CRJ has to go around. Can of worms in busy airspace— helos and /or jets being dispersed all over the sky.

Much better to do a rules based system and mutually exclude intersecting IFR app/deps and Helo Visual Routes.

Last edited by Stagformation; 7th February 2025 at 22:06 .

Subjects ATC CRJ FAA IFR See and Avoid Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

Someone Somewhere
February 07, 2025, 21:37:00 GMT
permalink Post: 11823944

Quote:

Originally Posted by West Coast

Yes. My point is that if visual is deemed not acceptable, the next step appears to be several Nm. If you are telling the controller to keep them clear, they can't be just missed ; they need to actually be properly radar separated.

This is following on from #960-964, discussing what would happen if the PAT flight(s) refused visual separation. It seems like it would throw a spanner in ATC's arrivals and they would probably get a response similar to that Lufthansa A380: Buzz off somewhere else.

Subjects ATC FAA Radar Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

West Coast
February 07, 2025, 22:59:00 GMT
permalink Post: 11824002

Quote:

Originally Posted by Stagformation

To be specific, para 7.9.4b of the handbook, here:
https://www.faa.gov/documentLibrary/...5-24_READY.pdf

As mentioned upthread, if not visually separated then either 500ft or 1.5mi applies.

Correct if this is all wrong, but in the accident sequence if the helo had responded \x91not visual yet, looking\x92 or words to that effect, then presumably a controller could allow the two to get a bit closer and then advise the conflicting traffic info to the helo again, say at 2.5mi. If helo visual, great \x97maintain visual separation, responsibly passes to helo.

This is what happened, although the very busy controller failed to re-state the position of the CRJ to direct the eyes of the helo crew onto the CRJ in order that they could actually see and avoid it.

However if not visual at say 2.5mi, well it\x92s a bit late, but the controller does still retain responsibility for separation and must apply the 500ft/1.5mi standard. Presumably instant vectors away while simultaneously climb to min vectoring altitude. Or the CRJ has to go around. Can of worms in busy airspace\x97 helos and /or jets being dispersed all over the sky.

Much better to do a rules based system and mutually exclude intersecting IFR app/deps and Helo Visual Routes.

I will not speculate specific to the accident. One more point to add about visual sep then you guys can go back to arguing about the accident. Visual separation isn\x92t just applied aircraft to aircraft. The local controller can observe both aircraft, (even if they don\x92t see each other) and apply visual separation. Such as two aircraft that are diverging but radar separation isn\x92t established.

Subjects ATC CRJ IFR Radar See and Avoid Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

BrogulT
February 08, 2025, 01:43:00 GMT
permalink Post: 11824068

Quote:

Originally Posted by 51bravo

I really run out of an idea what ATC would clear if the PAT25 crew didnt ask for "visual separation"...

There's a designated holding point on the route. IDK exactly what that means, but it must mean something, right?

The river is 4000 feet wide just south of that designated point. I imagine there is a procedure otherwise what would be the point?

The other option is that they would have to have the landing traffic go around.

Subjects ATC PAT25 Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

SINGAPURCANAC
February 08, 2025, 06:22:00 GMT
permalink Post: 11824114

Quote:

Originally Posted by Stagformation

To be specific, para 7.9.4b of the handbook, here:
https://www.faa.gov/documentLibrary/...5-24_READY.pdf

As mentioned upthread, if not visually separated then either 500ft or 1.5mi applies.

Correct if this is all wrong, but in the accident sequence if the helo had responded \x91not visual yet, looking\x92 or words to that effect, then presumably a controller could allow the two to get a bit closer and then advise the conflicting traffic info to the helo again, say at 2.5mi. If helo visual, great \x97maintain visual separation, responsibly passes to helo.

This is what happened, although the very busy controller failed to re-state the position of the CRJ to direct the eyes of the helo crew onto the CRJ in order that they could actually see and avoid it.

However if not visual at say 2.5mi, well it\x92s a bit late, but the controller does still retain responsibility for separation and must apply the 500ft/1.5mi standard. Presumably instant vectors away while simultaneously climb to min vectoring altitude. Or the CRJ has to go around. Can of worms in busy airspace\x97 helos and /or jets being dispersed all over the sky.

Much better to do a rules based system and mutually exclude intersecting IFR app/deps and Helo Visual Routes.

Could someone explain, how Twr ATCO in that particular enviroment, achieve required separation?
He is not radar qualified- so no headings or radar measurment distances applicable.
Where is prescribed what point is 1,5 Nm away from visual app for rwy 33? ( Note : Atco must achive required separation before that point)
or
At what point should be givem climb instruction for He to be 500' above arriving a/c before compromising 1,5Nm. If rate of climb is 1000 ft/min Helicopet need to climb for 40-50 seconds with the speed 180km/h it is 2 Nm or so - it means that instruction to climb should be given no latter than 4Nm from crossing point.
What is possibikity to spot particular aircraft for visual separation at distances more than 4Nm from crosssing points, duting the night and in bussy traffic enviroment?

Yes , I know it is Burund....

Subjects ATC ATCO CRJ IFR Radar See and Avoid Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

Stagformation
February 08, 2025, 11:52:00 GMT
permalink Post: 11824286

Quote:

Originally Posted by West Coast

Visual separation isn\x92t just applied aircraft to aircraft. The local controller can observe both aircraft, (even if they don\x92t see each other) and apply visual separation. Such as two aircraft that are diverging but radar separation isn\x92t established.

That\x92s absolutely right. If the controller takes a look outside, identifies the correct aircraft and sees that their lights (at night) are diverging then all is ok, separation assured.

In this case though the aircraft lights were rapidly converging, the radar repeater was flashing \x91CA\x92 but the helo has already requested and been given responsibility for collision responsibility. Crazy tragic situation.

Subjects ATC Radar Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

3 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

DaveJ75
February 08, 2025, 14:30:00 GMT
permalink Post: 11824387

Quote:

Originally Posted by West Coast

I keep re-reading this and it doesn't get any less amazing! To hell with the radar, I'll just look out of the window!

I would love to see it tried - obviously it would have to be over the desert in aircraft with no pax aboard! How would it work - do you just yell " Bloggs, left a bit " over the RT if all looks a bit close?

Subjects ATC Radar Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

No recorded likes for this post (could be before pprune supported 'likes').

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

West Coast
February 08, 2025, 16:20:00 GMT
permalink Post: 11824433

Quote:

Originally Posted by SINGAPURCANAC

Could someone explain, how Twr ATCO in that particular enviroment, achieve required separation?
He is not radar qualified- so no headings or radar measurment distances applicable.
Where is prescribed what point is 1,5 Nm away from visual app for rwy 33? ( Note : Atco must achive required separation before that point)
or
At what point should be givem climb instruction for He to be 500' above arriving a/c before compromising 1,5Nm. If rate of climb is 1000 ft/min Helicopet need to climb for 40-50 seconds with the speed 180km/h it is 2 Nm or so - it means that instruction to climb should be given no latter than 4Nm from crossing point.
What is possibikity to spot particular aircraft for visual separation at distances more than 4Nm from crosssing points, duting the night and in bussy traffic enviroment?

Yes , I know it is Burund....

How are you so sure the local controller isn\x92t as you put it \x93radar qualified\x94? I worked towers and issue vectors as needed.

Subjects ATC ATCO Radar Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

1 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

ATC Watcher
February 09, 2025, 17:01:00 GMT
permalink Post: 11825026

Just to put the things back into perspective : whether the controller had a radar display in front of him or not ,, whether there should have been a separate controller in the Heli frequency ,both would not have changed anything in this case since he delegated separation to the helicopter , The visual identification by the helicopter was confirmed ( twice) , instruction to pass behind was confirmed = controller no longer responsible , standard procedure in DC since the guys worked there , and he had a lot of other traffic to attend to.

To discuss what he could or should have done is just playing " Captain hindsight "

The procedure was wrong , the safety case botched , and as I understand, the " book " allowing all this was followed by both the controller and the helicopter pilot .
Let's discuss the procedures and visual separation delegation at night in busy airports instead on focusing on what the controller should have done , implying indirectly some form of responsibility in this accident..

Subjects ATC Pass Behind Pass Behind (All) Radar Separation (ALL) Visual Separation

Links are to this post in the relevant subject page so that this post can be seen in context.

15 recorded likes for this post.

Reply to this quoting this original post. You need to be logged in. Not available on closed threads.

Posts about: "Visual Separation" [Posts: 250 Page: 7 of 13]¶