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deltafox44
February 09, 2025, 18:15:00 GMT
permalink Post: 11825063

Quote:

Originally Posted by ATC Watcher

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..

Not implying any form of responsibility to anyone, the "book" says that in the case of a visual separation, if the 2 traffics converge, the controller should advise the other pilot. Perhaps the same controller on both frequencies was too busy to do so, and a second controller would have helped.

cf FAA Order JO 7110.65AA 7.2.1.a.2 Pilot-applied visual separation

Quote:

(d) If the aircraft are on converging courses, inform the other aircraft of the traffic and that visual separation is being applied.
(e)Advise the pilots if the radar targets appear likely to merge.

Last edited by deltafox44; 9th February 2025 at 19:04 . Reason: adding source

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

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deltafox44
February 10, 2025, 17:17:00 GMT
permalink Post: 11825626

Quote:

Originally Posted by Bogner

Not meaning to pick on you individually, it’s just that you have a great line to quote!
I think the point may be that in those 50yrs you may actually have made a mistake identifying an aircraft, but we don’t have the data. Just because you didn’t have a collision or Airmiss you can’t say for certain that everything worked perfectly.
If you mistakenly identify the wrong aircraft, but don’t realise and don’t actually hit anything and the other party also don’t notice/report, then the error is never recognised, nor recorded. Are we suggesting that this scenario has never happened in the history of aviation?
A flight that doesn’t end in a crash does not mean it was perfect.

+1
I think many pilots would have made a mistake indentifying : seen from the helo, there are 3 aircraft in final, plus 1 on take-off, at the same bearing, how can you tell for sure which is the one "just south of Wilson Bridge" ?

Quote:

Originally Posted by spornrad

NYT has attempted a reconstruction of the visual picture from the Blackhawk at the time of the first traffic alert, with the CRJ just south of Wilson Bridge.
They could only later identify the correct light spot by following its trajectory according to their mental image of the approach to 33.

Last edited by Senior Pilot; 10th February 2025 at 21:20 . Reason: Image source

Subjects Blackhawk (H-60) CRJ New York Times

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deltafox44
February 12, 2025, 19:32:00 GMT
permalink Post: 11826913

Quote:

Originally Posted by SINGAPURCANAC

I would like to ask if it is known number of aircraft at TWR Frequency( ies) at the moment of collision?
One ATCO, worked , at three separate frequency, three runways, 6 aircraft for arrival 01, one a/c 33, plus three helicopter, plus how many departures ( both active and approaching/crossing active runways) ?
Plus active estimate for a few aircraft more?
Ground vehicles, any?

There was a separate controller and frequency for ground control.

Subjects ATC ATCO

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deltafox44
February 14, 2025, 19:54:00 GMT
permalink Post: 11828159

Just heard NTSB briefing. It seems that the scapegoat will not be any of the humans involved, nor even the procedures, but the altimeter system of the black hawk (a 100 ft discrepancy) and the radio (they did not hear "circling" and "pass behind")

Subjects Blackhawk (H-60) NTSB Pass Behind Pass Behind (All)

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deltafox44
February 14, 2025, 22:44:00 GMT
permalink Post: 11828270

Quote:

Originally Posted by Lonewolf_50

No, hence the tower telling the Blackhawk to pass behind.
Seems to me like a reaction to seeing the Blackhawk right before impact and a reflex/reaction with intent to avoid.

The subtext for me is that the Blackhawk crew never saw them...but there's more for the NTSB to sort out, as the lady was VERY CLEAR about.

NTSB did not say (and nobody asked

) if there had been any discussion in the black hawk cockpit about the CRJ (where it was, whether the PF did see it or not) when PM requested visual separation

Last edited by deltafox44; 14th February 2025 at 23:19 .

Subjects Blackhawk (H-60) CRJ NTSB Pass Behind Pass Behind (All) Separation (ALL) Visual Separation

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deltafox44
February 15, 2025, 00:27:00 GMT
permalink Post: 11828318

Quote:

Originally Posted by TWT

Jennifer Homendy (NTSB Chair delivering the press conference) stated that the CVR of the Blackhawk had no discussion
relating to seeing the CRJ in the last seconds before impact. The crew didn't see it coming.

They stated the crew was likely wearing NVG, this would explain that

Subjects Blackhawk (H-60) CRJ NTSB NTSB Chair Jennifer Homendy Night Vision Goggles (NVG)

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deltafox44
February 16, 2025, 19:42:00 GMT
permalink Post: 11829420

Quote:

Originally Posted by Wide Mouth Frog

I was very surprised also to hear Jennifer tell us that the heliroutes have no lateral boundaries, which is a bit bizarre given that the Route 4 in the notes on the chart is described as following the East bank of the Potomac which is about on the left end of the diagram. Doesn't matter though, same problem there. Routes shouldn't be designed so that aircraft can infringe on landing (or any other kind) of passenger jet traffic.

She said there were no defined boundaries, though there were marked in blue on the maps. As already noted here, the width of the routes (as marked on the maps) is different from one map to another, especially when not at the same scale. There is a good reason for not having precise boundaries, they are VFR routes and there is no means to determine the position from the center of the route with a good accuracy, it is just visual navigation. And at night.

Subjects Route 4 VFR

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deltafox44
February 16, 2025, 23:34:00 GMT
permalink Post: 11829539

Quote:

Originally Posted by Stagformation

Accepting that the altimetry may be a side issue in this accident, but one explanation for the apparent altimeter discrepancy of around 100ft could be if pilots adjusted baro-alt to read same as radalt while over the water. Is this SOP in helicopter ops? Or were they given an altimeter setting to apply when they checked in on freq? The Potomac is tidal in that area with a tidal range 3ft or so, so radalt is near equivalent to amsl.

Who knows. If the 2 aircraft collided only for 2 ft, had the tide be low they would not have collided... Thus the tide would be to blame

Subjects: None

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deltafox44
February 19, 2025, 23:16:00 GMT
permalink Post: 11831829

Quote:

Originally Posted by airplanecrazy

Out of curiosity, I was wondering how “out of the ordinary” the flight path was for PA25 compared to other flights along Route 4. I found 65 such flights in January (there are probably some I missed) and I plotted where they crossed the runway approach. Note that the altitude is binned in 25' chunks, so you should assume that all altitudes just above 200' were actually at 200'. For any aircraft above 200' I DID NOT try to determine if they received clearance from ATC (which is permitted), and you SHOULD NOT assume that they didn't. I also threw in a rough breakout between daylight and night for each crossing. For the two PAT flights well offshore, I did not investigate any special ATC clearances they had. I apologize in advance for any errors as it is a bit tricky to plot and measure these distances.

Added note: The chart shows only crossings collected with ADS-B. I threw out all MLAT collected crossing because of inherent inaccuracy.

Helicopters crossing RWY 33 approach via Route 4 for January

Did you take QNH into account ? Ads-B gives pressure altitude

Interesting to note that, had PAT25 been at 200 ft and the CRJ just slightly below nominal glideslope, they would have collided too.

And that, had the CRJ been on the glide slope, it would have been way below PAT25 and would not have collided

Last edited by Senior Pilot; 20th February 2025 at 04:17 . Reason: Tidy up

Subjects ADSB (All) ATC CRJ PAT25 QNH Route 4

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deltafox44 February 09, 2025, 18:15:00 GMT permalink Post: 11825063	Quote: Originally Posted by ATC Watcher 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.. Not implying any form of responsibility to anyone, the "book" says that in the case of a visual separation, if the 2 traffics converge, the controller should advise the other pilot. Perhaps the same controller on both frequencies was too busy to do so, and a second controller would have helped. cf FAA Order JO 7110.65AA 7.2.1.a.2 Pilot-applied visual separation Quote: (d) If the aircraft are on converging courses, inform the other aircraft of the traffic and that visual separation is being applied. (e)Advise the pilots if the radar targets appear likely to merge. Last edited by deltafox44; 9th February 2025 at 19:04 . Reason: adding source Subjects ATC FAA 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. 1 recorded likes for this post. Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
deltafox44 February 10, 2025, 17:17:00 GMT permalink Post: 11825626	Quote: Originally Posted by Bogner Not meaning to pick on you individually, it’s just that you have a great line to quote! I think the point may be that in those 50yrs you may actually have made a mistake identifying an aircraft, but we don’t have the data. Just because you didn’t have a collision or Airmiss you can’t say for certain that everything worked perfectly. If you mistakenly identify the wrong aircraft, but don’t realise and don’t actually hit anything and the other party also don’t notice/report, then the error is never recognised, nor recorded. Are we suggesting that this scenario has never happened in the history of aviation? A flight that doesn’t end in a crash does not mean it was perfect. +1 I think many pilots would have made a mistake indentifying : seen from the helo, there are 3 aircraft in final, plus 1 on take-off, at the same bearing, how can you tell for sure which is the one "just south of Wilson Bridge" ? Quote: Originally Posted by spornrad NYT has attempted a reconstruction of the visual picture from the Blackhawk at the time of the first traffic alert, with the CRJ just south of Wilson Bridge. They could only later identify the correct light spot by following its trajectory according to their mental image of the approach to 33. Last edited by Senior Pilot; 10th February 2025 at 21:20 . Reason: Image source Subjects Blackhawk (H-60) CRJ New York Times 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.
deltafox44 February 12, 2025, 19:32:00 GMT permalink Post: 11826913	Quote: Originally Posted by SINGAPURCANAC I would like to ask if it is known number of aircraft at TWR Frequency( ies) at the moment of collision? One ATCO, worked , at three separate frequency, three runways, 6 aircraft for arrival 01, one a/c 33, plus three helicopter, plus how many departures ( both active and approaching/crossing active runways) ? Plus active estimate for a few aircraft more? Ground vehicles, any? There was a separate controller and frequency for ground control. Subjects ATC ATCO 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.
deltafox44 February 14, 2025, 19:54:00 GMT permalink Post: 11828159	Just heard NTSB briefing. It seems that the scapegoat will not be any of the humans involved, nor even the procedures, but the altimeter system of the black hawk (a 100 ft discrepancy) and the radio (they did not hear "circling" and "pass behind") Subjects Blackhawk (H-60) NTSB Pass Behind Pass Behind (All) 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.
deltafox44 February 14, 2025, 22:44:00 GMT permalink Post: 11828270	Quote: Originally Posted by Lonewolf_50 No, hence the tower telling the Blackhawk to pass behind. Seems to me like a reaction to seeing the Blackhawk right before impact and a reflex/reaction with intent to avoid. The subtext for me is that the Blackhawk crew never saw them...but there's more for the NTSB to sort out, as the lady was VERY CLEAR about. NTSB did not say (and nobody asked ) if there had been any discussion in the black hawk cockpit about the CRJ (where it was, whether the PF did see it or not) when PM requested visual separation Last edited by deltafox44; 14th February 2025 at 23:19 . Subjects Blackhawk (H-60) CRJ NTSB Pass Behind Pass Behind (All) 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.
deltafox44 February 15, 2025, 00:27:00 GMT permalink Post: 11828318	Quote: Originally Posted by TWT Jennifer Homendy (NTSB Chair delivering the press conference) stated that the CVR of the Blackhawk had no discussion relating to seeing the CRJ in the last seconds before impact. The crew didn't see it coming. They stated the crew was likely wearing NVG, this would explain that Subjects Blackhawk (H-60) CRJ NTSB NTSB Chair Jennifer Homendy Night Vision Goggles (NVG) 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.
deltafox44 February 16, 2025, 19:42:00 GMT permalink Post: 11829420	Quote: Originally Posted by Wide Mouth Frog I was very surprised also to hear Jennifer tell us that the heliroutes have no lateral boundaries, which is a bit bizarre given that the Route 4 in the notes on the chart is described as following the East bank of the Potomac which is about on the left end of the diagram. Doesn't matter though, same problem there. Routes shouldn't be designed so that aircraft can infringe on landing (or any other kind) of passenger jet traffic. She said there were no defined boundaries, though there were marked in blue on the maps. As already noted here, the width of the routes (as marked on the maps) is different from one map to another, especially when not at the same scale. There is a good reason for not having precise boundaries, they are VFR routes and there is no means to determine the position from the center of the route with a good accuracy, it is just visual navigation. And at night. Subjects Route 4 VFR 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.
deltafox44 February 16, 2025, 23:34:00 GMT permalink Post: 11829539	Quote: Originally Posted by Stagformation Accepting that the altimetry may be a side issue in this accident, but one explanation for the apparent altimeter discrepancy of around 100ft could be if pilots adjusted baro-alt to read same as radalt while over the water. Is this SOP in helicopter ops? Or were they given an altimeter setting to apply when they checked in on freq? The Potomac is tidal in that area with a tidal range 3ft or so, so radalt is near equivalent to amsl. Who knows. If the 2 aircraft collided only for 2 ft, had the tide be low they would not have collided... Thus the tide would be to blame Subjects: None 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.
deltafox44 February 19, 2025, 23:16:00 GMT permalink Post: 11831829	Quote: Originally Posted by airplanecrazy Out of curiosity, I was wondering how “out of the ordinary” the flight path was for PA25 compared to other flights along Route 4. I found 65 such flights in January (there are probably some I missed) and I plotted where they crossed the runway approach. Note that the altitude is binned in 25' chunks, so you should assume that all altitudes just above 200' were actually at 200'. For any aircraft above 200' I DID NOT try to determine if they received clearance from ATC (which is permitted), and you SHOULD NOT assume that they didn't. I also threw in a rough breakout between daylight and night for each crossing. For the two PAT flights well offshore, I did not investigate any special ATC clearances they had. I apologize in advance for any errors as it is a bit tricky to plot and measure these distances. Added note: The chart shows only crossings collected with ADS-B. I threw out all MLAT collected crossing because of inherent inaccuracy. Helicopters crossing RWY 33 approach via Route 4 for January Did you take QNH into account ? Ads-B gives pressure altitude Interesting to note that, had PAT25 been at 200 ft and the CRJ just slightly below nominal glideslope, they would have collided too. And that, had the CRJ been on the glide slope, it would have been way below PAT25 and would not have collided Last edited by Senior Pilot; 20th February 2025 at 04:17 . Reason: Tidy up Subjects ADSB (All) ATC CRJ PAT25 QNH Route 4 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.

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