Posts by user "Stagformation" [Posts: 29 Total up-votes: 30 Page: 1 of 2]ΒΆ

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Stagformation
February 02, 2025, 19:56:00 GMT
permalink Post: 11820055
CRJ approach briefing \x97 threats?
Pretty standard in my experience was to begin any approach briefing with my oppo with us airing the likely arrival routing and what the potential safety threats were for the arrival. Apart from the area chart showing the helo routes, there does seem to be a complete lack of any information about helo and VFR operations on any of the approach charts for KDCA.

This seems to me to be a big charting oversight, because these charts would be stage centre as any crew conducted their approach briefing and then made reference to them while they flew the actual approach. There\x92s simply nothing on there to suggest risk of mid-air collision might be a factor, where the hotspots are, or extra vigilance required etc.

Subjects KDCA  VFR

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

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Stagformation
February 07, 2025, 21:23:00 GMT
permalink Post: 11823937
Originally Posted by West Coast
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.
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

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

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Stagformation
February 08, 2025, 16:34:00 GMT
permalink Post: 11824442
Originally Posted by DaveJ75
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?

It happens all day long at airfields. Controller sees and gives clearances, eg remain dead side, go around, hold short of the active, expedite etc.

Subjects ATC  Radar

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Stagformation
February 10, 2025, 23:06:00 GMT
permalink Post: 11825761
Originally Posted by island_airphoto
The general one for me so far is how easy it is to see the wrong traffic at night and the next "do you see X" I get at night I am going to be triple-redundant sure and then some before saying I do.

Likewise ATC controllers ought to be a bit more sceptical whether they really believe a pilot who calls visual with traffic in amongst a whole bunch of other lights 7miles away at night!

Subjects ATC

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Stagformation
February 14, 2025, 23:34:00 GMT
permalink Post: 11828293
Originally Posted by deltafox44
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
NTSB didn\x92t mention much in the way of cross cockpit intercom chatter. Must be a lot more that could have been said about the SA on both aircraft, eg altimeter checks, visual lookout, intentions, perceptions, checklists\x85etc.

Subjects Blackhawk (H-60)  CRJ  NTSB  Separation (ALL)  Situational Awareness  Visual Separation

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Stagformation
February 15, 2025, 21:35:00 GMT
permalink Post: 11828846
Originally Posted by dbcooper8
The L model radar altimeter indicators each contain a pointer that indicates altitude on a linear scale from 0 to 200 feet (10 feet per unit) and a second-linear scale from 200 to 1500 feet (100 feet per unit). In other words 300 feet could easily be misread as 210 feet for the uninitiated. Worth noting the pointer is the width between 200 feet and 300 feet. Also, was the bug in use and if so what altitude was it set to?

Disconcerting that the PAT 25 crew, about to descend and fly less than 200 feet AGL , would not have investigate the discrepancy of 100 feet between their respective altimeters...

Details of instrumentation here:
https://apps.dtic.mil/sti/tr/pdf/ADA409934.pdf
Not completely obvious in the photo is the digital display of radar altitude just underneath the annotation ABS ALT. The technical manual also mentions a three digit radar altitude displayed on the HUD.

Last edited by Stagformation; 15th February 2025 at 23:01 .

Subjects HUD  Radar

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Stagformation
February 16, 2025, 23:07:00 GMT
permalink Post: 11829527
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.

So maybe the handling pilot misread 300ft radio and set an indicated 210ft on her baro-altimeter, while the pilot monitoring correctly set 300ft on his baro-altimeter, but without a crosscheck being performed. Subsequently if they adjusted flightpath to fly 200ft on the handling pilots baro alt then that would explain quite a lot\x85.

eg The helicopter flying at 290ft radio (actually 278ft at impact); the pilot monitoring\x92s nudge to the pilot handling to descend a bit; the transponder mode C reporting 300ft from the pressure altitude capsule in the handling pilots baro altimeter (which we\x92ve seen on the various ATC traffic videos).

Subjects ATC

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Stagformation
February 16, 2025, 23:49:00 GMT
permalink Post: 11829548
Originally Posted by deltafox44
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
df44, you miss the point or just being facetious \x97 just trying to understand why the helicopter might be flying along at 300ft, and not at 200ft, and with the two altimeters reading 100ft apart.

Subjects: None

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Stagformation
February 26, 2025, 16:29:00 GMT
permalink Post: 11836475
Originally Posted by AirScotia
Very interesting discussion with a former Blackhawk pilot who's often flown that route.
Interesting that he was often asked to hold at Hains Point.
Interesting and quite shocking, coming from a former standards/instructor pilot, re— normalisation of deviance.
eg. If you don’t catch all of a radio call meant for you, just reply with what you think the controller wants to hear you say and then comply with that — not, ‘Say again…’ and confirm your clearance. Also (implicitly while discussing LED lights) confirmed that the helicopter crew would not have been able to visually identify the correct conflicting traffic, yet made the habitual call, ‘Traffic’s visual, request visual separation’ and ok to proceed, with ATC complicit in the arrangement. Also don’t beat yourself up too much if you bust your altitude restriction right under where your route intersects with landing jets, while confirming this as the most safety critical part of the route.
Last edited by Stagformation; 26th February 2025 at 22:13 .

Subjects ATC  Blackhawk (H-60)

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Stagformation
February 26, 2025, 16:42:00 GMT
permalink Post: 11836483
Originally Posted by Lascaille
But that's actually the correct flow of events. If you weren't 100% sure but you readback what you think you heard and you don't get a correction then you did, actually, hear it correctly.
Really, what if your reply gets trampled on too?

Subjects: None

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Stagformation
February 26, 2025, 17:29:00 GMT
permalink Post: 11836513
Originally Posted by Lascaille
Are you genuinely asking for an elaboration of standard RT procedures?
It was a completely missed part of the clearance, not a misheard part that could be second guessed.

Subjects: None

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Stagformation
February 26, 2025, 19:10:00 GMT
permalink Post: 11836579
Originally Posted by Lascaille
When you say 'it' can you please be specific about what you're talking about? Because this discussion started with a theoretical ('If you don’t catch all of a radio call meant for you') i.e. a general case of 'people' replying with 'what they want to hear' but you seem to be now talking about a specific occurrence...?
Sure.

At 8:46:01 ATC called the helicopter with information about the CRJ, 1200’ over Wilson Bridge, circling to runway 33. The information about ‘…circling to…’ was not on the CVR of the helicopter. Inference is that part was missed (but not explicit). No requirement to read back traffic info, just acknowledge it.

At 8:47:42 the helicopter pilot stepped on the latter part of ATC’s transmission to the Blackhawk which was an instruction to ‘…pass behind the…’ The helicopter crew could not possibly have heard that instruction because they stepped on it themselves. Read back is required to an en-route clearance. Afterwards there was an intercom discussion between the helicopter pilots about whether they were to move further east.

Seems that two consecutive radio calls to the helicopter got corrupted which led to a breakdown in SA onboard the helicopter. Probably they had no idea that they needed to look left over the city lights to see the CRJ and were convinced their traffic was in the line up of jets on 01 extended centreline and therefore no factor.




Subjects ATC  Blackhawk (H-60)  CRJ  Situational Awareness

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Stagformation
February 28, 2025, 19:36:00 GMT
permalink Post: 11838025
Originally Posted by GlobalNav
Yes, really. That’s the purpose of the read back.
So in the accident in question the LC issued an en-route clearance to the Blackhawk to which there was no read back at all, because the helicopter crew never heard it. Subsequently I don’t think we see the LC chasing up for one, let alone correcting any errors as he ought — he was just too busy doing the work of two people. The purpose of the system broke down.

Subjects Blackhawk (H-60)

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Stagformation
March 01, 2025, 09:36:00 GMT
permalink Post: 11838415
Originally Posted by Capn Bloggs
IMO the fact that the helo crew didn't readback/acknowledge "pass behind" is irrelevant. Twice before, they told the LC that they had the CRJ in sight and requested visual sep, which was granted. Surely you don't specifically need to be told to not hit the CRJ after you've reported it in sight?

I think the LC saw what was unfolding and said that because he had concerns that the chopper didn't actually have the CRJ. He was right.
LC says, “PAT25, do you have the CRJ in sight?”

PAT25 says (for the second time), “Traffic visual, request visual separation”,
which is not true, evidently they were not visual at all because they crashed into the CRJ.

LC responds, “Visual separation approved, [pass behind the] CRJ,”
which clearance was issued on the false premise that PAT25 was visual. But PAT 25 only hears, “Visual separation approved…[pause]…CRJ,” because they briefly stepped on the LC’s transmission themselves. No read back is forthcoming; the LC should be expecting one but he fails to chase it up, because he’s too busy.

If PAT 25 realised he’s stepped on the middle part of the LC’s transmission to himself (which likely could have included an instruction) then he ought to be professional enough to say, “Stepped on, say again,” etc and make absolutely sure he knows what the clearance may have been. That was standard practice a long time ago, but no longer, it seems.

My original point was that in the Mover/Gonky video (post #1228) it was suggested that it’s perfectly OK to second guess what ATC might have said to you, reply to that, and then if no correction is forthcoming you can comply with your guess. As others have pointed out implicitly, that works if there’s only one error involved, but here there were three: an untrue statement, leading to a wrongly issued clearance, and a missing read back.

System broken.
Last edited by Stagformation; 2nd March 2025 at 23:42 .

Subjects ATC  CRJ  PAT25  Pass Behind  Pass Behind (All)  Separation (ALL)

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Stagformation
March 05, 2025, 10:44:00 GMT
permalink Post: 11841182
Originally Posted by Commando Cody
Keep in mind that no readback was required, and that type of instruction doesn't require a readback and according to the AIM is not even a type that "should" be read back, so the controller wouldn't be surprised if he didn't get one.
Even if a verbatim read back wasn’t required an acknowledgment of the amended instruction to “pass behind” was. The rapid fire response of PAT 25 omitted this and in my view simply confirms he had no idea of the imminent danger they were in.

https://www.faa.gov/air_traffic/publ...section_4.html
Para 2-4-3 note 2 says it all really.
Last edited by Stagformation; 5th March 2025 at 11:55 .

Subjects ATC

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Stagformation
March 05, 2025, 19:00:00 GMT
permalink Post: 11841477
Originally Posted by Capn Bloggs
In this scenario, there is zero information in the call to "pass behind" that indicates any imminent danger. All it does is further legitimise the previous two approvals for visual separation.
Now if the controller had said "you look to be tracking very close to the CRJ are you sure you can pass behind?" or similar, then maybe the helo crew would have got excited. A call like that might have even triggered a "holy sh1t" moment about the TCAS "Traffic". But as far as they were concerned, they knew they had the traffic in sight and could do the visual sep thing and even if they had heard "pass behind" they would have said/thought "well, obviously". Except they had the wrong aircraft. ATC had an idea they had the wrong aircraft but didn't get the message across.

As for the reference, same thing. The helo crew could have read-back "pass behind" but it wouldn't have achieved anything.
Yes, the RT added no more traffic information than before and completely failed to get the imminent danger across to the IP on the helicopter. However someone may have got a hint because there was a subsequent conversation between crew members about whether they should move further east. But we don’t know yet if that conversation was actually about traffic deconfliction. It could just be about accurate tracking of the left bank of the Potomac or something else entirely.

Subjects ATC  CRJ  Pass Behind  Pass Behind (All)  Separation (ALL)  TCAS (All)  Traffic in Sight  Visual Separation

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Stagformation
March 11, 2025, 23:10:00 GMT
permalink Post: 11845750
Originally Posted by LowObservable
Here's something I find inexplicable, and relevant to the entire safety case around the mix of airplane and helo ops.

The chart shows the dotted routes connecting 1 and 5 to the Pentagon helipad. But much of the time, the PAT helos would fly the red line - as I observed earlier, over a raised highway with light poles, and cutting under the RW15 approach at about half the distance to the runway end.

I just base this on what I can see locally. I walk almost daily parallel to the rail line and it was no big deal to see the PATs following 395 around the east side of the building - but that's not where the chart says Route 5 is.

By the way a midair over 395 would put debris into a heavily used outdoor sports complex.

PS Observed two more go-arounds from RW18 this afternoon!


https://www.airnav.com/airport/KJPN

FAA Information for KJPN, effective 20 Feb 2025, has amongst Additional Remarks:\x97

CAUTION - TFC PAT - KJPN EAST/WEST OPS. SPECIAL PRO TFC PAT. WHEN LDG W ALL ARR ACFT MAKE LEFT TFC CIRCLING THE PENTAGON AT OR BLW 200 FT. WHEN DEP E ALL ACFT MAKE RIGHT TFC CIRCLING THE PENTAGON AT OR BLW 200 FT

Subjects Route 5

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Stagformation
March 12, 2025, 10:40:00 GMT
permalink Post: 11846018
Originally Posted by LowObservable
Which is what they were not doing, at least on arrival. My vantage point for ops is about at the T on POWER PLANT on the map, so it was easy to see that the flightpath was east of the building.
Seems like the line you added on the chart is exactly what the Pentagon east/west arr/dep should look like. VFR helo Route 5 ends at Air Force Memorial and then it’s a transition route to Pentagon and Washington Monument. Helo traffic avoiding directly overflying the Pentagon.

One would hope traffic arriving/departing the Pentagon is coordinated tower to tower with DCA if traffic is approaching 15 and departing 33….
Last edited by Stagformation; 12th March 2025 at 10:51 .

Subjects DCA  Route 5  VFR

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