January 31, 2025, 20:16:00 GMT
permalink Post: 11818511
I think these are the regulations for general aviation (part 91).
Formation flying entails one aircraft following another. Definately not the case here. Also the CRJ was not informed...
On a sidenote: It is very convenient that they found an alternative description for the operations at SFO...
Formation flying entails one aircraft following another. Definately not the case here. Also the CRJ was not informed...
On a sidenote: It is very convenient that they found an alternative description for the operations at SFO...
Subjects
CRJ
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January 31, 2025, 20:43:00 GMT
permalink Post: 11818517
Based on the videos there should have been no difficulty picking out the lights of the CRJ, the helo is approaching it not quite head-on but definitely in the right front quadrant. And the CRJ is above all the city lights.
It is genuinely odd how they flew directly into this thing which must literally have been lighting up the interior of their cockpit. Also, why were they above the 200ft route ceiling?
(Still from the video referenced above by ORAC.)
Helo on the left
It is genuinely odd how they flew directly into this thing which must literally have been lighting up the interior of their cockpit. Also, why were they above the 200ft route ceiling?
(Still from the video referenced above by ORAC.)
Helo on the left
I have ZERO doubt that either crew had a slightest idea of what was about to happen. I can fill 30 minutes explaining my next 10 seconds but suffice to say, a complete surprise. “WTF was that” will be the short version.
Subjects
CRJ
Findings
Separation (ALL)
Visual Separation
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January 31, 2025, 20:43:00 GMT
permalink Post: 11818518
The new view of the event on the military forums is the clearest imaging yet. It shows the attitude of the helicopter from 5 seconds before the impact and finishes after surface impact of the two aircraft. It appears that the helicopter commenced a pitch up somewhere near 0.5s before impact, having had a fairly stable pitch up to that point. Would suggest the 60 crew detected the CRJ not much more than 0.5s before that point, ~1 before impact. A full aft cyclic at that point is not going to change the outcome, the impact was inevitable from shortly after the start of this video, and that is the fundamental physics problem with reliance on visual de-confliction.
Hope the pax on the RH side were fully distracted with a beautiful view of the capitol and Washington monuments. The 60 has nav, beacon/strobe and landing light on, which would have still been hard to see on a steady bearing line.
from the video here are observations that can be drawn, without the trauma of viewing the video (this is brutal, you are forewarned ) :
Hope the pax on the RH side were fully distracted with a beautiful view of the capitol and Washington monuments. The 60 has nav, beacon/strobe and landing light on, which would have still been hard to see on a steady bearing line.
from the video here are observations that can be drawn, without the trauma of viewing the video (this is brutal, you are forewarned ) :
Spoiler
Last edited by fdr; 31st January 2025 at 21:01 .
Subjects
CRJ
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January 31, 2025, 20:45:00 GMT
permalink Post: 11818520
I concur with this analysis
While the LC did not do anything unacceptable per se, the second affirmation of the CRJ being in sight would have been due to his concern about the proximity of the approaching aircraft. On this basis and with some benefit of hindsight, if he had been a bit more informative about the location and distance of the heli, this could have been a point of avoidance. Maybe there were some human factor priors were the heli pilots do not like what they deem as overly verbose comms or reassurance/verification calls, who knows.
Secondly, there appears to be an instrumentation issue, pilot error or both in one or both aircraft i.e. 1. no warning or awareness of warnings on a clearly impending incident - I only used TIS when I was flight training in the US some years ago, so again, some speculation. For CRJ, could be they had become accustomed to flying a few feet above helicopters there that they ignored such warnings 2. altitude deviation - could be mechanical, airmanship, wrong QNH etc.
Thirdly, the margins for error in the operating environment as many have commented appear too low, though in general there are low margins anyway when you are close to the ground.
If they [heli crew] were supposed to be following behind the CRJ, why were they getting that close to rwy 33 extended centreline or were they planning to turn once crossed? Was the CRJ centred laterally or did it perhaps slightly overshoot to the right?
I think it's more likely that the heli crew mistook the landing plane for #1 for rwy 01 rather than one taking off in my opinion, which leads me to think they may also have misidentified rwy 33 or the alignment to it at least. The latter may be an easy mistake at night. I would expect that part of the heli crew would have been very familiar with the territory, which makes it even more puzzling. The circling to land also adds a degree of ambiguity as to their understanding of the initial position notification or their expectation of where the landing a/c should be.
Anyway, we'll see when the prelim report comes out. I certainly hope there was a functioning CVR in the chopper.
While the LC did not do anything unacceptable per se, the second affirmation of the CRJ being in sight would have been due to his concern about the proximity of the approaching aircraft. On this basis and with some benefit of hindsight, if he had been a bit more informative about the location and distance of the heli, this could have been a point of avoidance. Maybe there were some human factor priors were the heli pilots do not like what they deem as overly verbose comms or reassurance/verification calls, who knows.
Secondly, there appears to be an instrumentation issue, pilot error or both in one or both aircraft i.e. 1. no warning or awareness of warnings on a clearly impending incident - I only used TIS when I was flight training in the US some years ago, so again, some speculation. For CRJ, could be they had become accustomed to flying a few feet above helicopters there that they ignored such warnings 2. altitude deviation - could be mechanical, airmanship, wrong QNH etc.
Thirdly, the margins for error in the operating environment as many have commented appear too low, though in general there are low margins anyway when you are close to the ground.
If they [heli crew] were supposed to be following behind the CRJ, why were they getting that close to rwy 33 extended centreline or were they planning to turn once crossed? Was the CRJ centred laterally or did it perhaps slightly overshoot to the right?
I think it's more likely that the heli crew mistook the landing plane for #1 for rwy 01 rather than one taking off in my opinion, which leads me to think they may also have misidentified rwy 33 or the alignment to it at least. The latter may be an easy mistake at night. I would expect that part of the heli crew would have been very familiar with the territory, which makes it even more puzzling. The circling to land also adds a degree of ambiguity as to their understanding of the initial position notification or their expectation of where the landing a/c should be.
Anyway, we'll see when the prelim report comes out. I certainly hope there was a functioning CVR in the chopper.
Last edited by my_call; 31st January 2025 at 22:37 .
Subjects
CRJ
QNH
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January 31, 2025, 20:53:00 GMT
permalink Post: 11818524
You need to go further back in the ATC playbacks. The helicopter crew had previously reported visual contact with the CRJ and requested (yes - requested) and been given responsibility for visual separation. The exchange you are referring to is the one which followed the collision alert and the controller's subsequent questioning of the helicopter crew as to whether they really did have the CRJ in sight.
Subjects
ATC
CRJ
DCA
Separation (ALL)
Visual Separation
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January 31, 2025, 21:04:00 GMT
permalink Post: 11818532
The new view of the event on the military forums is the clearest imaging yet. It shows the attitude of the helicopter from 5 seconds before the impact and finishes after surface impact of the two aircraft. It appears that the helicopter commenced a pitch up somewhere near 0.5s before impact, having had a fairly stable pitch up to that point. Would suggest the 60 crew detected the CRJ not much more than 0.5s before that point, ~1 before impact. A full aft cyclic at that point is not going to change the outcome, the impact was inevitable from shortly after the start of this video, and that is the fundamental physics problem with reliance on visual de-confliction.
Hope the pax on the RH side were fully distracted with a beautiful view of the capitol and Washington monuments. The 60 has nav, beacon/strobe and landing light on, which would have still been hard to see on a steady bearing line.
from the video here are observations that can be drawn, without the trauma of viewing the video (this is brutal, you are forewarned ) :
Hope the pax on the RH side were fully distracted with a beautiful view of the capitol and Washington monuments. The 60 has nav, beacon/strobe and landing light on, which would have still been hard to see on a steady bearing line.
from the video here are observations that can be drawn, without the trauma of viewing the video (this is brutal, you are forewarned ) :
Spoiler
Subjects
CRJ
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January 31, 2025, 22:24:00 GMT
permalink Post: 11818577
Subjects
CRJ
Separation (ALL)
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January 31, 2025, 23:15:00 GMT
permalink Post: 11818607
Rubbish
Listen to the audio at 1.10 to 1.13
Controller asks PAT25 if CRJ in sight NO ANSWER
Controller asks PAT25 to pass behind. NO ANSWER
Dealt with.
Listen to the audio at 1.10 to 1.13
Controller asks PAT25 if CRJ in sight NO ANSWER
Controller asks PAT25 to pass behind. NO ANSWER
Dealt with.
Subjects
ATC
CRJ
PAT25
Pass Behind
Pass Behind (All)
Pass Behind (PAT25)
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January 31, 2025, 23:21:00 GMT
permalink Post: 11818613
Subjects
ATC
CRJ
PAT25
Pass Behind
Pass Behind (All)
Pass Behind (PAT25)
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January 31, 2025, 23:31:00 GMT
permalink Post: 11818616
I am not a USA airspace expert, and I'm sure there are many rules that I don't know about, but having just read the FAR AIM section on 'pilot-applied visual separation' it reads to me, as an interested foreigner, that the LC can pass responsibility for separation to a pilot if they are visual. The class B separation criteria states:
VFR aircraft must be separated from VFR/IFR aircraft/ helicopter/rotorcraft that weigh more than 19,000 pounds and turbojets by no less than:
The rules for pilot-applied visual separation state:
VFR aircraft must be separated from VFR/IFR aircraft/ helicopter/rotorcraft that weigh more than 19,000 pounds and turbojets by no less than:
- 1 \xbd miles separation, or
- 500 feet vertical separation, or
- Visual separation, as specified in paragraph 7-2-1 , Visual Separation, paragraph 7-4-2 , Vectors for Visual Approach, and paragraph 7-6-7 , Sequencing.
The rules for pilot-applied visual separation state:
- If the aircraft are on converging courses, inform the other aircraft of the traffic and that visual separation is being applied.
- Advise the pilots if the radar targets appear likely to merge.
- If aircraft are on converging courses, inform the other aircraft of the traffic and that visual separation is being applied.
(ACID), TRAFFIC, (clock position and distance), (direction) BOUND, (type of aircraft), HAS YOU IN SIGHT AND WILL MAINTAIN VISUAL SEPARATION.
- Advise the pilots if the targets appear likely to merge.
Issue this advisory in conjunction with the instruction to maintain visual separation, the advisory to the other aircraft of the converging course, or thereafter if the controller subsequently becomes aware that the targets are merging.\x94
Subjects
ATC
CRJ
Radar
Separation (ALL)
VFR
Vertical Separation
Visual Separation
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January 31, 2025, 23:42:00 GMT
permalink Post: 11818626
This shows exactly the communications. The heli was told about the CRJ at 1200ft, going for 33. The heli said explicitly they had the plane in sight.
7:20 onwards.
Subjects
ATC
CRJ
PAT25
Pass Behind
Pass Behind (All)
Pass Behind (PAT25)
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January 31, 2025, 23:55:00 GMT
permalink Post: 11818633
NTSB briefing 31st January 2025
Helicopter single box combing CVR+DFDR has been recovered and looked good. No exterior damage.
Aircraft CVR had already been recovered, showed water ingress, was soaked in ionised water, then into oven for getting water out, still checking connectors \x85 but high confidence to get audio out.
Aircraft FDR already recovered, no water ingress, soaked in alcohol, looked good, ref 2,000 datapoints, high confidence to get data out.
NTSB investigation runs parallel to DoD investigation (I assume that will be the usual double), but independent, so NTSB got its own heli on-type licensed pilot in the team.
Investigation has a closely matching config CRJ available to match recovery of items and seating and cockpit config with items being recovered (which are refd on grid coordinates).
Main lift starts tomorrow and may take days. Prio 1 is still recovering all the victims. After that heavy lift of the big chunks starts on Sunday. This will take days.
ATCO interview(s) has already started. The history of the wider ATC team of controllers will look back for 24-72 hrs probably. But also at level of hiring and training.
PoB manifest are, by law, never published by NTSB and are excluded from FOIA.
Aircraft CVR had already been recovered, showed water ingress, was soaked in ionised water, then into oven for getting water out, still checking connectors \x85 but high confidence to get audio out.
Aircraft FDR already recovered, no water ingress, soaked in alcohol, looked good, ref 2,000 datapoints, high confidence to get data out.
NTSB investigation runs parallel to DoD investigation (I assume that will be the usual double), but independent, so NTSB got its own heli on-type licensed pilot in the team.
Investigation has a closely matching config CRJ available to match recovery of items and seating and cockpit config with items being recovered (which are refd on grid coordinates).
Main lift starts tomorrow and may take days. Prio 1 is still recovering all the victims. After that heavy lift of the big chunks starts on Sunday. This will take days.
ATCO interview(s) has already started. The history of the wider ATC team of controllers will look back for 24-72 hrs probably. But also at level of hiring and training.
PoB manifest are, by law, never published by NTSB and are excluded from FOIA.
Last edited by A0283; 1st February 2025 at 00:17 .
Subjects
ATC
ATCO
CRJ
NTSB
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February 01, 2025, 00:03:00 GMT
permalink Post: 11818637
Note I say \x91through\x92 and not \x91under\x92.
I\x92m sure it is done at many airports around the World and we have a similar procedure at a large international airport in East Asia.
HOWEVER, the idea that the 200ft ceiling on the heli route is designed to provide vertical separation from the approach is ludicrous.
I suspect that limit is imposed to allow clearance from the Take-off climb surface if using the opposite direction runways. That would indeed be possible from a flight procedure design point of view (TERPS or PANS-OPS).
The only safe way is to cross behind traffic on final laterally . In some ways it would be better for the heli to be at a higher altitude if on 33 but for simplicity of procedure they may have just made it a blanket 200ft regardless.
Our procedure has laterally separated holding points either side of final which is the clearance limit where the heli can orbit or delay as necessary until confirming the aircraft to pass behind is in sight. The heli is also advised where the next aircraft in the sequence is to further verify the correct aircraft is in sight and what margin they need to leave behind the one crossing behind. Again, being higher is better as they can avoid wake turbulence by remaining well an above the glide path and pass closer behind, well ahead of the following.
There is no doubt night time makes this a far more critical operation and requires full attention. In our operation the heli is also on the same frequency as the approach aircraft, so having separate positions to control fixed wing and helis wouldn\x92t have any benefit.
This controller was hugely busy however, handling departures as well. I can\x92t believe the speed of his transmissions - even as a controller for over 30 years I have trouble with all the abbreviated phrases- of course local pilots would be used to it and expecting clipped frequencies etc\x85
The trouble with a lot of these types of procedures is a lot is carried out as a box ticking exercise - heli calls requesting to cross the final ✅, LC provides the position of the aircraft to pass behind ✅, heli reports sighting and requests own visual separation ✅, approved ✅.
LC is no doubt expected to monitor compliance visually although hugely busy with other traffic on the runway. It does sound like he was doing so, especially when the CA goes off in the background audio and puts doubt in his mind the heli is passing clear of the CRJ. He asks again immediately.
The heli confirms, so difficult to further challenge the pilot.
In my view a poorly designed procedure which was guaranteed to place the 2 aircraft in the same position if an error was made.
Subjects
ATC
CRJ
Pass Behind
Pass Behind (All)
Separation (ALL)
Vertical Separation
Visual Separation
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February 01, 2025, 00:06:00 GMT
permalink Post: 11818639
To take the analogy first, when a PIC takes responsibility for separation from terrain, that PIC is putting only one aircraft and its POB at risk: The aircraft that the PIC is flying. In the case of the current tragedy, the system seems effectively to have put responsibility for the safety of two aircraft (at least) and all their POB into the lap of the PIC of one of them, on the basis of the (demonstrably dangerous) assumption that the PIC could reliably sight and follow a specific aircraft, at night, without any risk of misidentification.
Speaking of assumptions, I'm confident that the passengers on the CRJ would have assumed - reasonably I'd suggest - that the ATC system would always 'have their back'. I'm also confident that there will be a lot of grieving people at the moment, simply unable to grapple with the enormity of the realisation that the assumption was dangerously na\xefve. (Presumably, similar airspace arrangements continue in place at other locations, where the system continues to allocate responsibility similarly?)
Note that I do not presume to allocate responsibility for the tragedy to any individual/s. If I were pressed, I would allocate responsibility to whomever 'signed off' on arrangements in Class B airspace that entailed such a durr-obvious risk of precisely what happened.
Last edited by Lead Balloon; 1st February 2025 at 00:24 .
Subjects
ATC
CRJ
Separation (ALL)
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February 01, 2025, 00:18:00 GMT
permalink Post: 11818645
The two traffic items probably didn't hear each other.
Subjects
ATC
CRJ
Frequency 119.1
Frequency 134.35
PAT25
Pass Behind
Pass Behind (All)
Pass Behind (PAT25)
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February 01, 2025, 00:55:00 GMT
permalink Post: 11818670
I believe the controller was working two frequencies (duplexed?), probably 119.1 and 134.35, so raw LiveATC recordings would only pick up one side of the conversation.
The two traffic items probably didn't hear each other.
The two traffic items probably didn't hear each other.
Edit: here’s vid.
Last edited by joe_bloggs; 1st February 2025 at 04:33 . Reason: Added vid link
Subjects
ATC
CRJ
Frequency 119.1
Frequency 134.35
PAT25
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February 01, 2025, 02:33:00 GMT
permalink Post: 11818713
Captain Steeve has a good analyis and probably quite close to what actually happened. I agree with the comment on the video that
at the point which PAT25 initially requests visual separation and confirms traffic in sight, it looks like the AA5324 CRJ had already commenced right turn for circling approach at which point the brightest landing lights would be the aircraft behind as AA5324s would no longer be pointing directly at the helicopter. The brightest landing light is now the No.2 traffic which PAT25 identifies as their traffic and will probably now be fixated on due to confirmation bias. Terribly tragic and could happen to any pilot at night.
Subjects
CRJ
Circle to Land (Deviate to RWY 33)
PAT25
Separation (ALL)
Traffic in Sight
Visual Separation
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February 01, 2025, 03:09:00 GMT
permalink Post: 11818724
I tend to think ATC and, likely, the FAA will be shown as primary at fault with this:
1. The CRJ was on approach to 1 and then was asked to divert to 33. They complied, which added to their workload. From what I understand, that runway is rarely used for commercial aircraft. So, ATC added to the CRJ's workload while introducing and "unusual event." The CRJ crew appears to have acted professionally in changing their approach.
2. ATC didn't hold the helo short of the runway path, instead relied on them to correctly identify an aircraft, at night, over an urban area. That introduced a "single point of failure" to an already complex situation.
3. There was no way for the helo to pass safely under the CRJ at the altitude of impact.
3. I don't recall hearing ATC asking the CRJ if they could see the helo, though they already overtasked them. At that point, I don't think they could do anything at that point to prevent the collision.
Other factors may come into play, such as if ATC was properly staffed that night. I've read that DCA had two incidents that week where an aircraft had to perform a "go around" because of helo traffic. Also, was the CRJ's TCAS system operational?
This was completely preventable if things work they way they're supposed to.
1. The CRJ was on approach to 1 and then was asked to divert to 33. They complied, which added to their workload. From what I understand, that runway is rarely used for commercial aircraft. So, ATC added to the CRJ's workload while introducing and "unusual event." The CRJ crew appears to have acted professionally in changing their approach.
2. ATC didn't hold the helo short of the runway path, instead relied on them to correctly identify an aircraft, at night, over an urban area. That introduced a "single point of failure" to an already complex situation.
3. There was no way for the helo to pass safely under the CRJ at the altitude of impact.
3. I don't recall hearing ATC asking the CRJ if they could see the helo, though they already overtasked them. At that point, I don't think they could do anything at that point to prevent the collision.
Other factors may come into play, such as if ATC was properly staffed that night. I've read that DCA had two incidents that week where an aircraft had to perform a "go around" because of helo traffic. Also, was the CRJ's TCAS system operational?
This was completely preventable if things work they way they're supposed to.
Subjects
ATC
CRJ
DCA
FAA
TCAS (All)
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February 01, 2025, 03:34:00 GMT
permalink Post: 11818738
1. The CRJ was on approach to 1 and then was asked to divert to 33. They complied, which added to their workload. From what I understand, that runway is rarely used for commercial aircraft. So, ATC added to the CRJ's workload while introducing and "unusual event." The CRJ crew appears to have acted professionally in changing their approach.
2. ATC didn't hold the helo short of the runway path, instead relied on them to correctly identify an aircraft, at night, over an urban area. That introduced a "single point of failure" to an already complex situation.
3. There was no way for the helo to pass safely under the CRJ at the altitude of impact.
3. I don't recall hearing ATC asking the CRJ if they could see the helo, though they already overtasked them. At that point, I don't think they could do anything at that point to prevent the collision.
Other factors may come into play, such as if ATC was properly staffed that night. I've read that DCA had two incidents that week where an aircraft had to perform a "go around" because of helo traffic. Also, was the CRJ's TCAS system operational?
This was completely preventable if things work they way they're supposed to.
Everything else is moot, really...
Subjects
ATC
CRJ
DCA
FAA
Separation (ALL)
TCAS (All)
Visual Separation
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February 01, 2025, 10:05:00 GMT
permalink Post: 11818884
I just can't see that ATCduty peresonnel have any fault in this (apart from habitually lousy r/t). They did their thing correctly according to the procedures they were expected to work with.
The accident appears, almost certainly, to have been directly caused by the misidentification of conflicting traffic by the helo.
Fundamentally though the accident was entirely set up and enabled by critical faults in airspace usage and procedures, viz no vertical separation betwen the helo lane and glideslope at their point of intersection (to my mind simply incredible) and to a lesser extent perhaps the (again to my mind) extraordinary split frequency system. The first provides only one slice of swiss cheese - substantial vertical separation would add a second slice while the frequency thing is no cheese at all.
Despite what some commentators here and elsewhere seem to think there is never intended to be a situation when a helo passes under an aircraft on finals at 200ft. Helo traffic is held, or holds itself following a conditional clearance short of runway track before proceeding visually behind landing traffic or ahead of traffic on longer finals, exactly as is done at Heathrow. The difference is that in the event of an error at LHR there is 1000ft of vertical separation to add guartanteed separation if a helo wanders off track. Here there is next to none, it is very like a road intersection where cars on a minor road cross a big highway with conditional (orange flashing) traffic lights. Elsewhere in aviation this is just never done, there is always vertical separation too as a most basic safety precaution - ie like an overpass. The 1000ft also has the advantage that helo traffic is clearly visible on radar which is not the case when its grubbing along at 200ft.
Equally, the London helilanes too carry both mil and civ traffic, but critically both are on the same frequency (or if not the system re-broadcasts everything so it sounds as if they are) so everyone is playing the same ball. As every mil helo (surely?) has VHF nowadays why the digamma aren't procedures requiring its use when interracting in close/very close proximity with civ traffic?
Contributory factors include grossly sloppy r/t which employs open questions instead of closed ones - "do you see the CRJ on finals" when there are two unidentifiable aircraft visible on finals instead of "do you see the aircraft on 2 mile finals".
Doubtless there may be other consideration such as insufficient controllers and excessive workload too but that is not for me to say.
Bottom line is this appears to be a classic human factors accident induced by badly designed airspace, voice and control procedures.
+++++++++++
Why was the helo high? Not that I've ever done it but 200 ft or below at night over a big black hole of a river surrounded by bright city lights (800ft is my lowest) sounds pretty adventurous to me, it's very low indeed, and when a threator distraction is introduced at such low level in a helo one's instinct, even reflex is often to just squeeze back a little on the cyclic to give you a bit more space while your attention is drawn elsewhere. 100ft extra comes in a very short time and with less than 100ft of vertical separation from mis-identified traffic, that's it.
The accident appears, almost certainly, to have been directly caused by the misidentification of conflicting traffic by the helo.
Fundamentally though the accident was entirely set up and enabled by critical faults in airspace usage and procedures, viz no vertical separation betwen the helo lane and glideslope at their point of intersection (to my mind simply incredible) and to a lesser extent perhaps the (again to my mind) extraordinary split frequency system. The first provides only one slice of swiss cheese - substantial vertical separation would add a second slice while the frequency thing is no cheese at all.
Despite what some commentators here and elsewhere seem to think there is never intended to be a situation when a helo passes under an aircraft on finals at 200ft. Helo traffic is held, or holds itself following a conditional clearance short of runway track before proceeding visually behind landing traffic or ahead of traffic on longer finals, exactly as is done at Heathrow. The difference is that in the event of an error at LHR there is 1000ft of vertical separation to add guartanteed separation if a helo wanders off track. Here there is next to none, it is very like a road intersection where cars on a minor road cross a big highway with conditional (orange flashing) traffic lights. Elsewhere in aviation this is just never done, there is always vertical separation too as a most basic safety precaution - ie like an overpass. The 1000ft also has the advantage that helo traffic is clearly visible on radar which is not the case when its grubbing along at 200ft.
Equally, the London helilanes too carry both mil and civ traffic, but critically both are on the same frequency (or if not the system re-broadcasts everything so it sounds as if they are) so everyone is playing the same ball. As every mil helo (surely?) has VHF nowadays why the digamma aren't procedures requiring its use when interracting in close/very close proximity with civ traffic?
Contributory factors include grossly sloppy r/t which employs open questions instead of closed ones - "do you see the CRJ on finals" when there are two unidentifiable aircraft visible on finals instead of "do you see the aircraft on 2 mile finals".
Doubtless there may be other consideration such as insufficient controllers and excessive workload too but that is not for me to say.
Bottom line is this appears to be a classic human factors accident induced by badly designed airspace, voice and control procedures.
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Why was the helo high? Not that I've ever done it but 200 ft or below at night over a big black hole of a river surrounded by bright city lights (800ft is my lowest) sounds pretty adventurous to me, it's very low indeed, and when a threator distraction is introduced at such low level in a helo one's instinct, even reflex is often to just squeeze back a little on the cyclic to give you a bit more space while your attention is drawn elsewhere. 100ft extra comes in a very short time and with less than 100ft of vertical separation from mis-identified traffic, that's it.
Subjects
CRJ
Radar
Separation (ALL)
Vertical Separation
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