August 10, 2025, 07:27:00 GMT
permalink Post: 11936037
It's simple; the altitude restriction was never intended to be the sole method of separation. At most, it was an additional layer of protection. The controller wouldn't have cleared the Blackhawk to continue if they hadn't said they had the traffic in sight. But they did say that, whether it was true or not. ATC is a service provided to pilots, not an authority. Pilot-applied visual separation essentially overrides any procedure used by ATC. When you say "Traffic in sight," you are saying "I don't need your help maintaining separation, I have it under control and I take full responsibility."
Yet was not the controller required to inform the CRJ of the helicopter, which (as the inquiry noted) he failed to do? Thus a possible cross-check was lost.
Last edited by andihce; 10th August 2025 at 07:28 . Reason: Fixed quoting
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Blackhawk (H-60)
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August 10, 2025, 09:11:00 GMT
permalink Post: 11936070
Are you sure about that? My understanding of Class B airspace is that all aircraft proceed only on the basis of an ATC clearance. So to re-parse your statement\x85When a pilot says \x93Traffic in sight\x94 it just means he can see it, nothing more. It\x92s when he then says, \x93Request visual separation\x94 that he\x92s suggesting to the Local Controller he doesn\x92t need help with separation. And then it\x92s only when the Local Controller says, \x93Visual separation approved\x94 that the pilot takes on the responsibility for separation.
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August 10, 2025, 18:08:00 GMT
permalink Post: 11936308
Are you sure about that? My understanding of Class B airspace is that all aircraft proceed only on the basis of an ATC clearance. So to re-parse your statement\x85When a pilot says \x93Traffic in sight\x94 it just means he can see it, nothing more. It\x92s when he then says, \x93Request visual separation\x94 that he\x92s suggesting to the Local Controller he doesn\x92t need help with separation. And then it\x92s only when the Local Controller says, \x93Visual separation approved\x94 that the pilot takes on the responsibility for separation.
"Request visual separation" is non-standard.
https://www.faa.gov/air_traffic/publ...section_2.html
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August 10, 2025, 22:26:00 GMT
permalink Post: 11936398
Two interesting events noted on the recordings:
At about 20:00L, PCT calls helicopter traffic to PAT25. I count at least 12 statements between the two pilots regarding the called traffic in addition to radio transmissions to PCT regarding the traffic. Contrast this to the CRJ called traffic which generates zero discussion between the PAT25 flight crew.
At about 20:37L, there’s a traffic interaction between MUSL13 and BLJK1 (two helicopters) that generates a conflict alert. The DCA LC provides multiple traffic alerts to both aircraft, including direction, range, and altitude of the conflicting aircraft, even after visual separation is approved for BLJK1. Contrast this with the accident sequence where PAT25 is provided with a single traffic alert and the CRJ gets bupkis.
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CRJ
DCA
PAT25
Route 4
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August 10, 2025, 22:36:00 GMT
permalink Post: 11936403
Bit of confusion here . TCAS is not a separation tool , it is a last minute anti collision system . You are not obliged to monitor the screen, definitively not at 300ft on finals Not sure the CRJ crew noticed it . . Fact is the CRJ crew was not passed the traffic info . the reason why has been covered in the NTSB docket ( interview of the controller)
In class B , controllers will provide separation between IFR and VFR however they can delegate separation to an aircrfat visually following a strict procedure and phraseology .and issuing an ATC Instruction : " maintain visual separation "
In class B , controllers will provide separation between IFR and VFR however they can delegate separation to an aircrfat visually following a strict procedure and phraseology .and issuing an ATC Instruction : " maintain visual separation "
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NTSB Docket
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August 11, 2025, 11:39:00 GMT
permalink Post: 11936649
That route forced helicopters below 200 ft., how can that not be unsafe?
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August 12, 2025, 00:21:00 GMT
permalink Post: 11936996
No, they're exactly the same. If you say "traffic in sight" then the controller will immediately say "Maintain visual separation."
"Request visual separation" is non-standard.
https://www.faa.gov/air_traffic/publ...section_2.html
"Request visual separation" is non-standard.
https://www.faa.gov/air_traffic/publ...section_2.html
Absolutely, it was a non-standard discourse. But however you look at what was said, PAT 25 requested the change to visual separation. Meaning PAT25 correctly believed he was under standard 1.5nm/500ft separation at the time and that he needed LC approval for Visual separation to be applied. The change in the separation standard being applied did not happen until the LC accepted PAT 25\x92s traffic visual report and authorised the change. It\x92s not an automatic change made just on the pilot\x92s say so, ie by reporting visual, which I think is what you may be implying (happy if you correct me). Both pilot and LC are necessary (and both made errors here).
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PAT25
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August 12, 2025, 01:18:00 GMT
permalink Post: 11937016
Absolutely, it was a non-standard discourse. But however you look at what was said, PAT 25
requested
the change to visual separation. Meaning PAT25 correctly believed he was under standard 1.5nm/500ft separation at the time and that he needed LC approval for Visual separation to be applied. The change in the separation standard being applied did not happen until the LC accepted PAT 25’s traffic visual report and
authorised
the change. It’s not an automatic change made just on the pilot’s say so, ie by reporting visual, which I think is what you may be implying (happy if you correct me). Both pilot and LC are necessary (and both made errors here).
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PAT25
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Visual Separation
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August 12, 2025, 04:41:00 GMT
permalink Post: 11937043
As I posted on here before I had that exact same scenario happen to me on runway 33 in DCA. Traffic closing on a collision course on TCAS. Tower reported the traffic had us in sight. When the traffic closed to \xbd mile with no vector change apparent We went around from 400 feet. We never saw the traffic. Tower chewed my butt saying the traffic had us in sight. I didn\x92t care.
In the case you quote, Tower reported the traffic had you in sight. In the case in question, AA5342 was not provided traffic by the DCA LC.
In the case you quote, did Tower say that the traffic was going to maintain own separation? Did Tower provide a bearing/direction and distance to this traffic? Did Tower provide the height of the traffic?
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August 12, 2025, 10:13:00 GMT
permalink Post: 11937144
. I'd often get from Twr on joining the circuit at my various destinations, and having confirmed I'd got traffic XYZ in sight, a clearance "Roger, C/S, keeping that traffic in sight, report Final XX. You are No 2 to the XYZ.". From that point on, my positioning was determined by me based on visual separation with the other traffic - so not totally identical to the DCA accident but the principle was the same - I was responsible for remaining clear of XYZ and positioning appropriately behind them (including accounting for wake/runway occupancy effects etc). Occasionally I'd then get "C/S, new clearance - report
ready
for L/R base." usually with a reason if there was time - often it was App not leaving TWR a big enough gap to sneak me in between 2 IFR arrivals.
In other words, Twr would delegate separation to me with the initial clearance but, if for whatever reason, they became unhappy - I got issued with a revised, more restrictive, clearance. Similarly, if I lost sight of the traffic at any point after the initial "Report Final" clearance, it was my responsibility to advise ATC that I was no longer visual with XYZ (ie I could no longer comply with the clearance ATC had given me) and ATC would then update my clearance on that basis - "..... report ready for base" or similar until they could visually assure themselves of separation. Indeed, on those occasions, it was not unknown for ATC to say "C/S, I have you both in sight - that traffic is well ahead of you, report Final XX, No 2". I was thus relieved of my responsibility to self-position.
What ATC giveth away in their airspace ATC can taketh back again in their airspace!
Now, "normalised deviation" may skew such a way of working such as PAT routinely expecting to get what they ask for and ATC routinely giving them what they want......... Not saying that happened at DCA but............ Also, I've lost track in the Thread if PAT were visual but with another a/c or the intended one but simply "lost it" at some point........... And whether visual separation at night in such busy airspace was wise ............
Last edited by Hot 'n' High; 12th August 2025 at 10:23 .
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DCA
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August 12, 2025, 10:55:00 GMT
permalink Post: 11937179
Re ATC assigning own separation, that happens here in Oz. IIRC, it went like this: "Report sighting the 737 on final"..."Traffic sighted"..."Follow as number two". Although critically, Our Oz AIP states:
Re TCAS, my Boeing manual states
Change 7 came in some years ago. I wonder if the CRJ's TCAS was the same and the TA was inhibited a few seconds before the collision, which was below 500ft?
Re "normalised deviation", I'm not sure this applies here. Normalised deviation means deviating from published (perportedly safe) procedures, with no adverse consequences, so the deviations continue. In this case, it's pretty obvious that the "published procedures" were flawed in the first place.
Originally Posted by
AIP Australia
(3) where an aircraft has been instructed to maintain own separation from an IFR aircraft, ATC will issue traffic information to the pilot of the IFR aircraft, including advice that responsibility for separation has been assigned to the other aircraft;
Originally Posted by
Boeing
The Traffic Advisory (TA) is inhibited below 1,100 feet (+100 feet) AGL for TCAS change 6 computers and below 500 feet (+100 feet) for TCAS change 7 computers.
Re "normalised deviation", I'm not sure this applies here. Normalised deviation means deviating from published (perportedly safe) procedures, with no adverse consequences, so the deviations continue. In this case, it's pretty obvious that the "published procedures" were flawed in the first place.
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August 12, 2025, 11:11:00 GMT
permalink Post: 11937189
Last edited by Stagformation; 12th August 2025 at 19:11 .
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ATC
CRJ
DCA
Night Vision Goggles (NVG)
Separation (ALL)
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August 12, 2025, 15:40:00 GMT
permalink Post: 11937327
I may be mistaken, but my understanding is that the controller doesn't really have the option to deny visual separation. The regulations don't mention any response except 'approved.' The word 'approved' does seem to imply that it could also be denied, but there's no mention of how, when, or why that would be done. Even if they do have the option to deny, as far as I can tell there's no guidance on how to make that decision. Obviously there's no way for a controller to know whether a pilot truly has the correct aircraft in sight.
Here, the helicopter pilots had obviously routinely been lying to LC (and getting away with it!), so the system broke down.
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Separation (ALL)
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August 12, 2025, 16:04:00 GMT
permalink Post: 11937346
thank you for your reply!
It looks safe if the jet crews can't see the helicopters?
Good thing they let only professional operators use heli route 4, then.
I take your point that the route was legal (if unsafe).
My impression is that the 500/1000 ft clearance rule exists so when a pilot gets disoriented, or suffers a flight control problem, they don't immediately smash into things; and that they have a chance to find a suitable place to
crash
land, should the need arise. The latter is obviously solved when the river is right there.
If you don't have that altitude, you're missing a slice of cheese; and of course you won't feel it missing unless you need it, which is often the case with safety.
If the heli route had been higher up, then letting helicopters fly it on visual separation while runway 33 was in use wouldn't be "normalising deviance", it'd be normalising insanity, i.e. the illusion of "safety" that the 200 ft restriction provided would have been absent. The fact that someone at the FAA thought, "it'll be ok if we force the helicopters down to an unsafe altitude routinely" speaks of eroded safety standards to me. There are some disasters (and at least one impressive Space Shuttle fireball) that resulted from eroded safety standards, where managers convinced themselves it would still be ok--until it wasn't.
not intending to be cynical, but it makes the helos blend in nicely with the background, sort of out of the way for rwy 01/19 traffic (=95% of total)
I wonder how many pilots on rwy 01/19 really perceived this section of the routing as unsafe (when flown correctly = hugging the shoreline at max 200ft).
I wonder how many pilots on rwy 01/19 really perceived this section of the routing as unsafe (when flown correctly = hugging the shoreline at max 200ft).
taking the nearby airport out of the equation, I wonder if any of the professional operators on this route 4 section, ever felt that this low-level flying was (unnecessarily) unsafe
I take your point that the route was legal (if unsafe).
My impression is that the 500/1000 ft clearance rule exists so when a pilot gets disoriented, or suffers a flight control problem, they don't immediately smash into things; and that they have a chance to find a suitable place to
If you don't have that altitude, you're missing a slice of cheese; and of course you won't feel it missing unless you need it, which is often the case with safety.
If the heli route had been higher up, then letting helicopters fly it on visual separation while runway 33 was in use wouldn't be "normalising deviance", it'd be normalising insanity, i.e. the illusion of "safety" that the 200 ft restriction provided would have been absent. The fact that someone at the FAA thought, "it'll be ok if we force the helicopters down to an unsafe altitude routinely" speaks of eroded safety standards to me. There are some disasters (and at least one impressive Space Shuttle fireball) that resulted from eroded safety standards, where managers convinced themselves it would still be ok--until it wasn't.
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FAA
Route 4
Separation (ALL)
Visual Separation
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August 13, 2025, 22:32:00 GMT
permalink Post: 11938086
Are there procedures published? If Yes, was everybody following those procedures?
If Yes, no normalisation of deviance. The procedures themselves were/are flawed, not the execution of them.
If No, then there's normalisation of deviance. The users are not following the procedures and if those procedures have been in place for some time, the users have been "getting away with it" ie NoD until now.
If Yes, no normalisation of deviance. The procedures themselves were/are flawed, not the execution of them.
If No, then there's normalisation of deviance. The users are not following the procedures and if those procedures have been in place for some time, the users have been "getting away with it" ie NoD until now.
Each time someone gets away with a close call, the "normalization" sweeps the issue under the rug, instead of the procedure being questioned. The longer the procedure is in use, the more confidence there may be that it is acceptable, when in fact it may just be a matter of time until some unlikely and disastrous event occurs "by chance".
Having worked in a non-aviation area that became heavily proceduralized after all too many mistakes had been made, I have seen more than a few flawed procedures that continued to be employed despite warning signs, typically because of time, management, cost, etc. pressures. Modifying and reviewing a procedure can be a time consuming process as many individuals and management structures can be involved in a complicated system.
In the present case (without knowing exactly what procedures were in effect), I could argue that permitting visual separation at night in this particular environment was a key procedural flaw. But it was accepted as there had been no accidents as a result, even as perhaps traffic density, etc. increased risk over time.
Last edited by andihce; 13th August 2025 at 23:53 . Reason: addition
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Close Calls
Separation (ALL)
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August 14, 2025, 08:04:00 GMT
permalink Post: 11938210
That would perhaps be a standard definition of "normalization of deviance". But I think there is a possible extension of that definition, which allows for the procedure to be flawed or open to interpretation, and considers "deviance" as
departure from safe operation
, even while the procedure is technically observed. It could also be the case that the procedure was initially valid, but became marginal as a result of changes in its area of application since its inception.
In the present case (without knowing exactly what procedures were in effect), I could argue that permitting visual separation at night in this particular environment was a key procedural flaw. But it was accepted as there had been no accidents as a result, even as perhaps traffic density, etc. increased risk over time.
We don't know if the heli crew thought they had seen that traffic (but picked the wrong one) or not, though the CVR conveys the impression they didn't, because they didn't talk about it (like they did about other traffic earlier in the flight).
It's also difficult to judge distance if all you see is a light, in your night vision goggles.
And it's especially difficult if you fail to predict the other aircraft's maneouver. The CRJ rolled out on final only 7 seconds before the collision. Until then, from a purely visual standpoint, everything would've looked fine. It required the heli crew to be aware of where the runway 33 extended centerline was (and where they were) to avoid being where the CRJ was going.
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CRJ
Separation (ALL)
Traffic in Sight
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August 14, 2025, 10:40:00 GMT
permalink Post: 11938285
@ Musician :
Yes but that is only the visual separation procedure .
When we talk about un safe " procedures" (plural) it is mostly the airspace design and the actions written and put in place which have to be performed to keep that design safe . That part : "conflicting paths used simultaneously with only 100 or 200ft separation " is the basic " unsafe " part of the procedures. For me at least .
The procedure calls for the heli pilot to report "traffic in sight", which they did. The unsafe part is that likely they hadn't actually seen the traffic.
When we talk about un safe " procedures" (plural) it is mostly the airspace design and the actions written and put in place which have to be performed to keep that design safe . That part : "conflicting paths used simultaneously with only 100 or 200ft separation " is the basic " unsafe " part of the procedures. For me at least .
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Separation (ALL)
Traffic in Sight
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August 14, 2025, 14:00:00 GMT
permalink Post: 11938382
@ Musician :
Yes but that is only the visual separation procedure .
When we talk about un safe " procedures" (plural) it is mostly the airspace design and the actions written and put in place which have to be performed to keep that design safe . That part : "conflicting paths used simultaneously with only 100 or 200ft separation " is the basic " unsafe " part of the procedures. For me at least .
Yes but that is only the visual separation procedure .
When we talk about un safe " procedures" (plural) it is mostly the airspace design and the actions written and put in place which have to be performed to keep that design safe . That part : "conflicting paths used simultaneously with only 100 or 200ft separation " is the basic " unsafe " part of the procedures. For me at least .
"Visual separation" is the procedure that's supposed to make this safe, i.e. ensure that the actual separation is never that low.
Did DCA actually schedule conflicting flights without visual separation procedures?
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ATC
DCA
Preliminary Report
Separation (ALL)
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August 14, 2025, 14:53:00 GMT
permalink Post: 11938401
75 feet separation between the heli route and the 33 glide path, if I remember the preliminary report correctly.
"Visual separation" is the procedure that's supposed to make this safe, i.e. ensure that the actual separation is never that low.
Did DCA actually schedule conflicting flights without visual separation procedures?
"Visual separation" is the procedure that's supposed to make this safe, i.e. ensure that the actual separation is never that low.
Did DCA actually schedule conflicting flights without visual separation procedures?
I don't know how to answer your question. FAA said that there was no "procedural separation" plan in place. Army stated that when 33/15 was in use, the protocol/procedure was for Army to automatically hold at one of two points (depending on direction of travel) to await clearance past the extended runway center-line, or to request clearance past the same. So the 75-foot topic in theory maybe is relevant if considering wake/rotor-related turbulence, but not for physical separation of aircraft.
I cannot imagine that airlines take military helo flights into account while scheduling flights. What is important is the maximum commercial operations/flight density that can be accommodated (e.g. per hour). So when FAA allows commercial traffic to really get dense, this makes conflicts with random helo traffic more likely.
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DCA
FAA
Preliminary Report
Separation (ALL)
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August 14, 2025, 16:25:00 GMT
permalink Post: 11938451
Note that the apparently informal procedure of holding helicopters at Hains Pt or golf balls was an effective method of deconflicting Route 4 and 15/33 traffic. However it appears that the use of this \x93procedure\x94 was left to the discretion of the individual controller.
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CRJ
DCA
Route 4
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VFR
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