January 30, 2025, 09:10:00 GMT
permalink Post: 11817027
Helicopter Low Level Routes are standardized through out the DC area.
Military Operations are 24/7/365 due to National Security issues.
https://www.loc.gov/resource/g3851p....,0.268,0.125,0
Military Operations are 24/7/365 due to National Security issues.
https://www.loc.gov/resource/g3851p....,0.268,0.125,0
I have never flown there but if there's regular helicopter traffic 150ft below an ILS or circling approach airline crews familiar with the airport might tend to disregard TCAS proximate traffic, etc. as normal backdrop chatter.
Even when flying behind similar aircraft on an ILS in daylight and good visibility it takes quite some time to see that preceding traffic is slowing down as it only starts to "grow" at an alarming rate when quite close. I have witnessed that twice, once caused by self and another time caused by mismatched speed instructions from ATC. I have resolved to never accept visual separation to preceding traffic at night and while the European aversion to visual approaches might be excessive, high density night ops based on visual separation don't seem to be a good idea even without that crash.
Subjects
ATC
Circle to Land (Deviate to RWY 33)
Radar
Route 4
Separation (ALL)
TCAS (All)
Visual Separation
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January 30, 2025, 10:04:00 GMT
permalink Post: 11817076
As a regular tourist to Alexandria, I have often watched the DCA traffic and the helos transiting along the Potomac shoreline north of the Wilson Bridge on Route 4. In this tragic instance, the Blackhawk [PAT25} not only seems to be higher than the published procedure but also further west [ie over the river]. And according to that radar plot [post 80] , in the last moments it seems to rurn right [ie further west] exacerbating the situation.
MPN11, former Mil ATCO
MPN11, former Mil ATCO
Subjects
ATCO
Blackhawk (H-60)
DCA
PAT25
Radar
Route 4
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January 30, 2025, 11:29:00 GMT
permalink Post: 11817139
The chart itself shows the <not above 200 MSL> symbol for the segment where the collision took place. That combined with the \x93via East bank\x85\x94 provides (some) procedural separation with traffic on final.. not much but some if the Route 4 traffic follows the east bank\x85 and stays below 200\x92\x85.
Subjects
CNN
Route 4
Separation (ALL)
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January 30, 2025, 12:09:00 GMT
permalink Post: 11817176
https://www.youtube.com/watch?v=CiOybe-NJHk
vasaviation
vasaviation
Subjects
PAT25
Route 4
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January 30, 2025, 12:30:00 GMT
permalink Post: 11817187
A 'human resource' failure rather than 'engineering' per se - though I fully agree with your comments otherwise. Remove the risk entirely - the best prevention, rather than try to minimise the probability of failure by adding more steps or 'aids'.
Low level helicopter Route 4 makes sense for the ease of helicopter positioning point of view and minimising noise etc impacts - following a river. But not right under an approacj path and especially not at night, using visual separation !
Subjects
Route 4
Separation (ALL)
Visual Separation
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January 30, 2025, 13:08:00 GMT
permalink Post: 11817221
I am rather surprised by the route the helicopter took, this looks like quite a high risk in itself.
Yes, there is noise abatement and all that, but is there a compelling reason beyond that why the heli had to track the river in opposite direction to the flow of arriving airliners? Certainly, it would have been possible for a controller, radar-equipped or not, to hold the heli east of the field and clear him for a midfield crossing on heading 270 or so as an airliner is just touching down on 33 or 01 and the next one is still a few miles out? That would have kept him well out of the approach sector, allowed for a possible go-around of an arriving airliner and also would not interfere with departing traffic.
Surely, someone familiar with DCA can explain...
Yes, there is noise abatement and all that, but is there a compelling reason beyond that why the heli had to track the river in opposite direction to the flow of arriving airliners? Certainly, it would have been possible for a controller, radar-equipped or not, to hold the heli east of the field and clear him for a midfield crossing on heading 270 or so as an airliner is just touching down on 33 or 01 and the next one is still a few miles out? That would have kept him well out of the approach sector, allowed for a possible go-around of an arriving airliner and also would not interfere with departing traffic.
Surely, someone familiar with DCA can explain...
I would expect the airliner not to have to take any avoiding action, as it\x92d be IFR on a standard arrival for RW33. I would expect ATC to inform them of the helicopter traffic below them on the east side of the river.
I would expect the helicopter traffic to ultimately be responsible for avoidance, and they\x92d I guess be flying \x91Special VFR\x92*. But as they\x92re in controlled airspace then they should have been warned (which apparently they were) about the arriving civil traffic.
If the helicopter was, indeed, following Route 4 then what led to the discrepancy in position & height is conjecture. Also why they confirmed traffic in sight yet still collided is conjecture (& It\x92s possible they had their own emergency)
*) does \x91Special VFR\x92 exist/ apply for \x91night VMC\x92 ops in US controlled airspace ? it\x92s a long time since my FAA/US flying days\x85\x85
Subjects
ATC
DCA
IFR
Route 4
Traffic in Sight
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January 30, 2025, 13:23:00 GMT
permalink Post: 11817231
Im not \x93familiar with DCA\x94 but from the Terminal Chart & discussion here it\x92s clear that the heli was following the transit route 4, which would be a normal activity. Though it\x92s also possible their plan was to leave route 4 & cross the river towards the airfield\x85.
I would expect the airliner not to have to take any avoiding action, as it\x92d be IFR on a standard arrival for RW33. I would expect ATC to inform them of the helicopter traffic below them on the east side of the river.
I would expect the helicopter traffic to ultimately be responsible for avoidance, and they\x92d I guess be flying \x91Special VFR\x92*. But as they\x92re in controlled airspace then they should have been warned (which apparently they were) about the arriving civil traffic.
If the helicopter was, indeed, following Route 4 then what led to the discrepancy in position & height is conjecture. Also why they confirmed traffic in sight yet still collided is conjecture (& It\x92s possible they had their own emergency)
*) does \x91Special VFR\x92 exist/ apply for \x91night VMC\x92 ops in US controlled airspace ? it\x92s a long time since my FAA/US flying days\x85\x85
I would expect the airliner not to have to take any avoiding action, as it\x92d be IFR on a standard arrival for RW33. I would expect ATC to inform them of the helicopter traffic below them on the east side of the river.
I would expect the helicopter traffic to ultimately be responsible for avoidance, and they\x92d I guess be flying \x91Special VFR\x92*. But as they\x92re in controlled airspace then they should have been warned (which apparently they were) about the arriving civil traffic.
If the helicopter was, indeed, following Route 4 then what led to the discrepancy in position & height is conjecture. Also why they confirmed traffic in sight yet still collided is conjecture (& It\x92s possible they had their own emergency)
*) does \x91Special VFR\x92 exist/ apply for \x91night VMC\x92 ops in US controlled airspace ? it\x92s a long time since my FAA/US flying days\x85\x85
Subjects
ATC
DCA
IFR
Route 4
Traffic in Sight
VFR
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January 30, 2025, 13:43:00 GMT
permalink Post: 11817252
The Route 4 restrictions are in the Terminal Chart somebody else posted further up the thread: \x93Rt4: Fort Washington over Potomac River to Wilson Bridge. Then via East bank of Potomac River to Anacostia River. Intercept Route 1 at Anacostia River. Altitudes: At or below 600 feet MSL to Wilson Bridge. Begin descent from 600 feet MSL to arrive at 300 feet MSL over Wilson Bridge. Then at or below 200 feet MSL North of Wilson Bridge.\x94
The chart itself shows the <not above 200 MSL> symbol for the segment where the collision took place. That combined with the \x93via East bank\x85\x94 provides (some) procedural separation with traffic on final.. not much but some if the Route 4 traffic follows the east bank\x85 and stays below 200\x92\x85.
The chart itself shows the <not above 200 MSL> symbol for the segment where the collision took place. That combined with the \x93via East bank\x85\x94 provides (some) procedural separation with traffic on final.. not much but some if the Route 4 traffic follows the east bank\x85 and stays below 200\x92\x85.
Southbound, not above 200 feet to Goose Island, then not above 300 before the Wilson Bridge.
Screenshot elsewhere suggests the Blackhawk was initially at 200, then climbed early to 300, and then to 350\x85.
Subjects
Blackhawk (H-60)
Route 4
Separation (ALL)
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January 30, 2025, 13:55:00 GMT
permalink Post: 11817263
Waiting to happen
Heli route 4 is at or below 200ft if I read the chart correctly.
Approach traffic seems to be approx 400-500ft at this point.
Which turnip decided it would be OK to allow vertical separation of 300ft on a busy approach path? And allow it VFR at night?
This accident was baked in. Bound to happen at some point.
Approach traffic seems to be approx 400-500ft at this point.
Which turnip decided it would be OK to allow vertical separation of 300ft on a busy approach path? And allow it VFR at night?
This accident was baked in. Bound to happen at some point.
Subjects
Route 4
Separation (ALL)
VFR
Vertical Separation
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January 30, 2025, 14:10:00 GMT
permalink Post: 11817272
The helicopter\x92s right turn was directly over a golf course, not a residential neighborhood. It was probably done for noise abatement reasons, because it then turned left and proceeded down more directly over the river.
The golf course is on a peninsula in the river, so the helicopter was flying over water before and after it made the two turns.
The golf course is on a peninsula in the river, so the helicopter was flying over water before and after it made the two turns.
Subjects
ATC
DCA
Radar
Route 4
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January 30, 2025, 14:32:00 GMT
permalink Post: 11817282
The track in your image is not an accurate representation of PAT25s actual flight path. The leaked ATC radar track
here
and the VASAviation recreation
here
are more representative. There was no sharp RH turn to cross over the Potomac Park golf courses, it was a gentle RH turn to follow the published Route 1 to Route 4 helicopter transition around DCA.
You could contact them if you want and tell them it\x92s wrong. No offense intended.
Even if it wasn\x92t a sharp turn, it was done over a golf course and their flight path was probably dictated by noise abatement reasons, as are those flown by jets flying into DCA.
Subjects
ATC
DCA
Radar
Route 4
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January 30, 2025, 14:37:00 GMT
permalink Post: 11817285
my earlier point related to responsibility for separation\x85. and that the helo would be VFR (if following the low-level transit Route 4) and the airliner IFR. I was unsure if there was a special category for VFR at night\x85
apologies for sowing any confusion\x85\x85
Subjects
ATC
IFR
Route 4
VFR
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January 30, 2025, 15:23:00 GMT
permalink Post: 11817324
Heli route 4 is at or below 200ft if I read the chart correctly.
Approach traffic seems to be approx 400-500ft at this point.
Which turnip decided it would be OK to allow vertical separation of 300ft on a busy approach path? And allow it VFR at night?
This accident was baked in. Bound to happen at some point.
Approach traffic seems to be approx 400-500ft at this point.
Which turnip decided it would be OK to allow vertical separation of 300ft on a busy approach path? And allow it VFR at night?
This accident was baked in. Bound to happen at some point.
In this case, the aircraft was flying an approach to one runway with a circle-to-land on RW-33. Ask any pilot; a circle to land in itself ups the work load. The margin for error of any kind at DCA is small and the 5200 foot runway isn't all that long. Even on a simple landing where none of these considerations are an issue, at some point the pilots reduce their "see and avoid" efforts and concentrate their efforts on achieving the proper line up and glide slope, rate of descent, aircraft configuration, flap setting, etc. etc. etc. In other words, the complicated routine required to safely land an airliner these days is already close to task overload even when things are going well. Add in the fact that it's night time at a very busy airport and looking out the window gets shoved pretty far down the "to do" list. But generally speaking, the system works because big busy airports pretty much operate using IFR rules and nearly all the aircraft are under close control. I other words, even on a crystal clear day under VFR flight conditions, someone is keeping a very close eye on the airliners coming and going from major airports. If a pilot makes a mistake and levels off at the wrong altitude, for example, there is a very good chance a controller will catch that error immediately even on a sunny VFR day. And that's a good thing because truth-be-told, when an airliner is seconds from touch down these days, there isn't much "see and avoid" going on. That's just the way it is.
But apparently DCA routinely has all sorts of helo traffic buzzing around under modified VFR flight rules. The pilots are talking to a controller but without being under the same sort of close control which is usually associated with how airliners operate. And they do that night and day, trusting the helo pilots to not make a mistake. But it looks like someone DID make a mistake last night and nobody caught it in time.
Subjects
ATC
Circle to Land (Deviate to RWY 33)
DCA
FAA
IFR
Route 4
See and Avoid
Separation (ALL)
VFR
Vertical Separation
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January 30, 2025, 16:03:00 GMT
permalink Post: 11817358
In my understanding, the minimum safe separation in altitude is 500 feet.
As the approach to R33 crosses IDTEK (over the East bank of the river) at about 490 feet MSL, there is no way another aircraft can safely pass underneath at 200 feet MSL.
Thus, I think, the helicopter route RT 4 must be closed whenever an approach (visual or RNAV) to R33 is underway.
As the approach to R33 crosses IDTEK (over the East bank of the river) at about 490 feet MSL, there is no way another aircraft can safely pass underneath at 200 feet MSL.
Thus, I think, the helicopter route RT 4 must be closed whenever an approach (visual or RNAV) to R33 is underway.
Subjects
Route 4
Separation (ALL)
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January 30, 2025, 18:16:00 GMT
permalink Post: 11817497
If that published in AIP route 4 crossing under the final approach path of RWY 33 says max 200 ft and according the calculations made by Luc Lion earlier the altitude of the CRJ was, if not exactly on the PAPI , very close to it at 300 Ft in less than a mile before TDZ. But 100 ft separation is not a normal civil vertical separation standard in controlled airspace, for an IFR flight. it is 500 ft minimum in our books. . One of the roots of the problem is right there : a published route where you need a visual military type separation to make it work . And it may have worked hundreds of times before , sometimes with luck I am sure, but this time it did not and this was just an accident waiting to happen written in the book.
To answer an earlier question , Yes they have CISM , NATCA is good at this , they will take care of the controllers.
@ fdr : our posts crossed each other , fully agree with you .
To answer an earlier question , Yes they have CISM , NATCA is good at this , they will take care of the controllers.
@ fdr : our posts crossed each other , fully agree with you .
Subjects
Accident Waiting to Happen
CRJ
IFR
Route 4
Separation (ALL)
Vertical Separation
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January 30, 2025, 19:33:00 GMT
permalink Post: 11817579
Yes ATC could have done better, and heli pilots could have done better. But they were in high pressure time critical nighttime environment with seconds to make decisions.
The people who design the charts and procedures have days and weeks to think things through, in a nice safe office, on the ground, going 0kts with good lighting.
Unless I'm missing something, it would seem that route 4 design is the main culprit here.
The people who design the charts and procedures have days and weeks to think things through, in a nice safe office, on the ground, going 0kts with good lighting.
Unless I'm missing something, it would seem that route 4 design is the main culprit here.
Subjects
ATC
Route 4
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January 30, 2025, 20:08:00 GMT
permalink Post: 11817608
Yes ATC could have done better, and heli pilots could have done better. But they were in high pressure time critical nighttime environment with seconds to make decisions.
The people who design the charts and procedures have days and weeks to think things through, in a nice safe office, on the ground, going 0kts with good lighting.
Unless I'm missing something, it would seem that route 4 design is the main culprit here .
The people who design the charts and procedures have days and weeks to think things through, in a nice safe office, on the ground, going 0kts with good lighting.
Unless I'm missing something, it would seem that route 4 design is the main culprit here .
Subjects
ATC
Probable Cause
Route 4
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January 30, 2025, 20:09:00 GMT
permalink Post: 11817611
I’m sure Edward A. Murphy Jr would have had something to say about Route 4.
Of Murphy’s Law, for those wondering
SPlot
Of Murphy’s Law, for those wondering
SPlot
Subjects
Route 4
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January 30, 2025, 23:24:00 GMT
permalink Post: 11817756
OK so what's your interpretation of the rules here then?
The airliner is under IFR rules on its flight plan until it gets changed to a different runway, when it's then VFR.
The chopper is under VFR, stooging along a river at 200 ft and avoiding traffic on approach to Reagan by visual clues alone.
Radar useless as the aircraft are too low.
Airliner TCAS useless as inhibited, even if it can decode the military transponder's data.
Radio situational awareness compromised as chopper on UHF, airliner on VHF. So each aircraft can neither hear the other nor the ATC instructions to that aircraft.
It's difficult to see aircraft at night against a backdrop of a city with thousands of lights. And when you're gonna hit something, as others have said, that light doesn't move relative to you, so you don't notice it - it just blends into the background lights.
It only takes the chopper to misidentify the aircraft it's supposed to go behind and to therefore turn into the path of the airliner it was supposed to avoid - draw the map with the vectors and it all makes sense. These two aircraft ended up in the Potomac, but they could have ended up in much worse places in terms of loss of life on the ground.
Seems to me it's been an accident waiting to happen for some time.
The airliner is under IFR rules on its flight plan until it gets changed to a different runway, when it's then VFR.
The chopper is under VFR, stooging along a river at 200 ft and avoiding traffic on approach to Reagan by visual clues alone.
Radar useless as the aircraft are too low.
Airliner TCAS useless as inhibited, even if it can decode the military transponder's data.
Radio situational awareness compromised as chopper on UHF, airliner on VHF. So each aircraft can neither hear the other nor the ATC instructions to that aircraft.
It's difficult to see aircraft at night against a backdrop of a city with thousands of lights. And when you're gonna hit something, as others have said, that light doesn't move relative to you, so you don't notice it - it just blends into the background lights.
It only takes the chopper to misidentify the aircraft it's supposed to go behind and to therefore turn into the path of the airliner it was supposed to avoid - draw the map with the vectors and it all makes sense. These two aircraft ended up in the Potomac, but they could have ended up in much worse places in terms of loss of life on the ground.
Seems to me it's been an accident waiting to happen for some time.
"Radar useless as the aircraft are too low." - It seems there's valid radar returns from both aircraft. the FAA has a good diagram of the Potomac TRACON radar sites, about 10 different radars, and having visited the TRACON several times, they readily explain there's another nearly facility that is a duplicate of their radar feed, but for national security. I assume there's coverage till the river service for security to prevent someone from sneaking up the river with bad ideas
"Radio situational awareness compromised as chopper on UHF, airliner on VHF. " - I fly in the area and in my experience everyone is on the same VHF, they might be also duped to UHF and can hear everybody on my handheld. You hear AF-1 all the time on freq.
"The chopper is under VFR, stooging along a river at 200 ft and avoiding traffic" - Most of the area NE of the airfield in a prohibited area, and there's a lot of military installations within 5 miles of DC that they are shuttling around, so that path seems perfectly acceptable given the numerous constraints. there's nothing wrong with a helo corridor as long as you stay within it and maintain the prescribed altitude. Also, it's not like KDCA is some secret place, the flight paths are pretty well known if that's where you work. It's popular to sit in parks on both ends and watch the planes, there's literally millions of local people that know exactly the planes are coming and going on both directions. so if you're a helo there, you know where the hot spots are. Likewise, its not just any helo in that area, everyone is vetted, fingerprinted in the inner FRZ.
" on approach to Reagan by visual clues alone" - The UH-60 was not going to DCA, the assumption was it was using the helo route 4 corridor. All the UH-60Ls I've seen have full glass with moving map and I'm assuming a magenta line for the helo corridor.
Fun Fact - Calling it "Reagan" will get you tarred and feathered in the area. Folks refuse to utter the name and for years (decades) the Metro refused to rename the station until legally forced.
Last edited by Senior Pilot; 31st January 2025 at 00:05 . Reason: Prescribed/proscribed
Subjects
ATC
Accident Waiting to Happen
DCA
FAA
Hot Spots
IFR
KDCA
Pass Behind
Pass Behind (All)
Radar
Route 4
Situational Awareness
TCAS (All)
VFR
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January 31, 2025, 02:15:00 GMT
permalink Post: 11817851
I almost didn\x92t bother replying because I originally posted that Hains Point, the peninsula in the river, is not a residential area. I didn\x92t say it was a gated community.
Who cares if it is a municipal golf course or not, because nobody is going to play golf at around 8:40 PM in the dark of night.
My point was that helicopters might fly over it because nobody would care about the noise, and people in residential neighborhoods do, whether the residential neighborhoods are officially listed as a noise abatement areas or not.
https://www.flyreagan.com/about-airp...raft-noise-faq
Who cares if it is a municipal golf course or not, because nobody is going to play golf at around 8:40 PM in the dark of night.
My point was that helicopters might fly over it because nobody would care about the noise, and people in residential neighborhoods do, whether the residential neighborhoods are officially listed as a noise abatement areas or not.
https://www.flyreagan.com/about-airp...raft-noise-faq
And it's pretty clear there's no turn at all in the first place, and that since there's no ads-b, this data point is an interpolation error. there's several other PAT ATC tracks from a the last few weeks doing the same training loop and the are all keeping in the rt4 and keeping 300ft msl
Subjects
ATC
PAT25
Route 4
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