Posts about: "TCAS (All)" [Posts: 152 Page: 1 of 8]ΒΆ

MichaelKPIT
January 30, 2025, 03:01:00 GMT
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Post: 11816798
Commentators are saying they can\x92t understand how TCAS didn\x92t prevent this. Do military Blackhawks use TCAS? (Honest question\x85)

Subjects TCAS (All)

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Capn Bloggs
January 30, 2025, 03:12:00 GMT
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Post: 11816805
Originally Posted by Michael
Commentators are saying they can’t understand how TCAS didn’t prevent this.
In my old type, TCAS didn't issue RAs below 900ft, only TAs, and no voice warnings below 500ft.

Subjects TCAS (All)  TCAS RA

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KRviator
January 30, 2025, 03:16:00 GMT
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Post: 11816807
Originally Posted by MichaelKPIT
Commentators are saying they can\x92t understand how TCAS didn\x92t prevent this. Do military Blackhawks use TCAS? (Honest question\x85)
Memory's a bit hazy after 25 years, but I'm pretty sure none of the Aussie S70's had TCAS - so you'd be limited to a TA only if the system wasn't already inhibited due low altitude as CB alluded to above^^.

Subjects TCAS (All)

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MechEngr
January 30, 2025, 03:21:00 GMT
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Post: 11816809
How did the top many measures that are in place to prevent this not prevent this?

TCAS
ATC
ADS-B
See and Avoid
Filing a flight plan
Not operating in controlled airspace without a transponder
Not operating at a landing altitude for aircraft on final for a well used runway
Announcing an intention to cross a well used approach
Position lights/strobes
Landing lights

Just spitballing, but there's a non-zero chance NVGs were in use in the helicopter.

It sucks that the best part of this is the airplane was a CRJ, not a larger airliner. Most all those passengers would have survived the initial collision and been aware during the fall to the river.

I feel rage.

Subjects ADSB (All)  ATC  CRJ  Night Vision Goggles (NVG)  See and Avoid  TCAS (All)

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galaxy flyer
January 30, 2025, 03:23:00 GMT
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Post: 11816811
Likely, if US Army, no TCAS or ADS.

Subjects TCAS (All)

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physicus
January 30, 2025, 05:30:00 GMT
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Post: 11816894
The military helicopter did have a Mode S transponder, but no ADS-B out. The CRJ had a standard transponder with ADS-B out. In all my data sources, the helicopter is visible but only as an MLAT target, so its position in all the flight tracking feeds (ADSB Exchange and FR24) is inferred via time of arrival difference of the Mode-S signal at various receiver stations in the area (i.e. within 200-300m position precision).

TCAS however can operate off Mode-S signals alone, but as others have pointed out, during the late approach phase of a flight, TCAS RA is inhibited (but the target would have caused a TRAFFIC alert still and shown yellow/red on the TCAS display). The helicopter crew assuring the frequency they have identified them would have led them to believe they were cutting it close but will avoid.

It would have been a luck of the draw situation for the CRJ crew to see and avoid the helicopter. It's very hard to see a couple of light points moving against a sea of ground point lights at night. Assuming the CRJ had its logo light on, their only chance would have been for the helicopter crew to spot them (which they claimed they did?)

Subjects ADSB (All)  ADSB Out  CRJ  See and Avoid  TCAS (All)  TCAS RA

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Simplythebeast
January 30, 2025, 07:02:00 GMT
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Post: 11816927
Originally Posted by MechEngr
How did the top many measures that are in place to prevent this not prevent this?

TCAS
ATC
ADS-B
See and Avoid
Filing a flight plan
Not operating in controlled airspace without a transponder
Not operating at a landing altitude for aircraft on final for a well used runway
Announcing an intention to cross a well used approach
Position lights/strobes
Landing lights

Just spitballing, but there's a non-zero chance NVGs were in use in the helicopter.

It sucks that the best part of this is the airplane was a CRJ, not a larger airliner. Most all those passengers would have survived the initial collision and been aware during the fall to the river.

I feel rage.
what is a \x93non-zero chance\x94? Is it the same as a chance or more like a certainty? Confused by what seems like an American expression.

Subjects ADSB (All)  ATC  CRJ  Night Vision Goggles (NVG)  See and Avoid  TCAS (All)

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moosepileit
January 30, 2025, 07:59:00 GMT
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Post: 11816973
Originally Posted by Return_2_Stand
Having followed many of the near misses in the US in recent years, I find US ATC procedures scary. I always thought it was just a matter of time.
Crossing runway finals at 200' at a distance that puts you wthin reach of the circling jet- tempting fate. TCAS in TA only, not RA by height, No ADSB In or Out improvement in this regime.

Final hole, see and avoid- target invisibe, sighted AAL3130 on Rwy1 straight in, not enough dissonance in all that to realize you cannot be following that next plane...

Subjects ADSB (All)  ADSB In  ATC  Close Calls  See and Avoid  TCAS (All)

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Alpine Flyer
January 30, 2025, 09:10:00 GMT
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Post: 11817027
Originally Posted by Chock Puller
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



According to the procedure map Route 4 (which seems to be the one they were closest to) is supposed to be flown at or below 200ft north of Wilson Bridge. The Radar plots that surfaced so far show the helicopter above 300ft. Even if they misset their altimeter they probably have a radar altimeter and a 75% difference in height should be apparent to a crew familiar with low-level flying.

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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Locked door
January 30, 2025, 11:39:00 GMT
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Post: 11817145
The whole USA aviation sector needs root and branch reform, there have been so many near misses in recent years that this accident was inevitable, it was just a question of when.

The majority of people inside the system don\x92t realise how bad it is because it\x92s all they\x92ve ever known. We have American contributors here who routinely tell us it\x92s ok to switch to TA only to avoid \x93nuisance\x94 RA\x92s, who will not follow an RA as they have the traffic in sight, who will accept visual separation at night (day is bad enough) or very late visual switches, who think LAHSO is a good idea. USA ATC think it\x92s acceptable to \x93slam dunk\x94 a heavy jet, get shirty when foreign operators refuse a questionable clearance, literally forget about an aircraft once it has accepted visual separation. The system allows uncontrolled VFR traffic within 500ft of commercial operations which is madness.

I operated the 747-400 around the planet for over a decade, the USA was one of the most threat laden environments we went to. Lovely people, just insane procedures. In that time I experienced a TCAS RA on vectors to JFK, was sent around and put in the hold as punishment on short final in Miami for refusing LAHSO, had multiple super high workload approaches to SFO combined with the crazy policy of pairing aircraft on approach. I witnessed a Singapore aircraft being refused a diversion to Boston from JFK fifteen minutes after they stated what time they would be leaving the hold and where they would be going resulting in a fuel mayday and an unplanned diversion to a regional airport. I lost count of the times I was chastised for refusing a visual approach and visual separation in congested airspace or a very late visual switch.

On most of the planet the human is the last line of defence in a multi layered safety environment. In the USA the human is often the only line of defence, while the environment they are in is super high workload significantly reducing their capacity to trap safety issues.

Unless there is a marked attitude shift in all parties involved in aviation in the USA this will happen again, potentially quite soon.

Stay safe out there

LD

Subjects ATC  Close Calls  Land and Hold Short  Separation (ALL)  TCAS (All)  TCAS RA  Traffic in Sight  VFR  Visual Separation

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Jojobray
January 30, 2025, 13:16:00 GMT
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Post: 11817227
Poignant truth

Originally Posted by Locked door
The whole USA aviation sector needs root and branch reform, there have been so many near misses in recent years that this accident was inevitable, it was just a question of when.

The majority of people inside the system don\x92t realise how bad it is because it\x92s all they\x92ve ever known. We have American contributors here who routinely tell us it\x92s ok to switch to TA only to avoid \x93nuisance\x94 RA\x92s, who will not follow an RA as they have the traffic in sight, who will accept visual separation at night (day is bad enough) or very late visual switches, who think LAHSO is a good idea. USA ATC think it\x92s acceptable to \x93slam dunk\x94 a heavy jet, get shirty when foreign operators refuse a questionable clearance, literally forget about an aircraft once it has accepted visual separation. The system allows uncontrolled VFR traffic within 500ft of commercial operations which is madness.

I operated the 747-400 around the planet for over a decade, the USA was one of the most threat laden environments we went to. Lovely people, just insane procedures. In that time I experienced a TCAS RA on vectors to JFK, was sent around and put in the hold as punishment on short final in Miami for refusing LAHSO, had multiple super high workload approaches to SFO combined with the crazy policy of pairing aircraft on approach. I witnessed a Singapore aircraft being refused a diversion to Boston from JFK fifteen minutes after they stated what time they would be leaving the hold and where they would be going resulting in a fuel mayday and an unplanned diversion to a regional airport. I lost count of the times I was chastised for refusing a visual approach and visual separation in congested airspace or a very late visual switch.

On most of the planet the human is the last line of defence in a multi layered safety environment. In the USA the human is often the only line of defence, while the environment they are in is super high workload significantly reducing their capacity to trap safety issues.

Unless there is a marked attitude shift in all parties involved in aviation in the USA this will happen again, potentially quite soon.

Stay safe out there

LD
Sadly this is probably the most honest and accurate description of flying into the USA I\x92ve read in many years.

Subjects ATC  Close Calls  Land and Hold Short  Separation (ALL)  TCAS (All)  TCAS RA  Traffic in Sight  VFR  Visual Separation

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10 DME ARC
January 30, 2025, 14:10:00 GMT
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Post: 11817271
Might have missed it but the CRJ wasn't given any traffic on the Blackhawk?? Plus the Blackhawk was only asked if he had the CRJ insight very late on and no updated traffic information given! The ATCO was obviously concerned but that concern should have included traffic information as directly ahead of the Blackhawk was two CRJ one much further out which was no factor!!
Plus does the Blackhawk have a TCAS screen?? That would have been invaluable to pick out the traffic!

Subjects ATCO  Blackhawk (H-60)  CRJ  TCAS (All)

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SASless
January 30, 2025, 14:51:00 GMT
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Post: 11817298
TCAS for the helicopter....hmmmmmm.....I am at 200 feet per the Routing Requirement.....would I suppose Airplanes might be above me even if on a conflicting flight path?

How much higher at a minimum should they be over the required flightpath for the Helicopter Low Level route (at that point I see it as being 200 feet AGL or below)

But indications seem to show the Helicopter not at the required height above ground....although that number has some doubts due to various reasons.

Do standard IAP Procedures by Airlines require use of Glide Slope information even when VFR.....which would make me ask the question what height the RJ should have been at at the point it collided with t he helicopter.

Was the RJ Crew using Glide Slope information as part of their VFR Approach procedure for the designated runway? The CVR will let us know that in time probably.

The other question is at what point would the RJ Crew have benefit of visual glide slope lighting for the RWY 33?

Any of you Airline Pilots care to address that issue and assess that for us.

Here is the Airport data for Reagan International that shows the Instrument Approaches that are available. Can one derive a reasonable height above ground for the collision point....and/or a distance from the Touchdown Point of RWY33 for comparison to what seems to be the height and distance from the TD point?

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

Subjects TCAS (All)  VFR

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ALTSELGREEN
January 30, 2025, 15:12:00 GMT
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Post: 11817313
Originally Posted by Locked door
The whole USA aviation sector needs root and branch reform, there have been so many near misses in recent years that this accident was inevitable, it was just a question of when.

The majority of people inside the system don\x92t realise how bad it is because it\x92s all they\x92ve ever known. We have American contributors here who routinely tell us it\x92s ok to switch to TA only to avoid \x93nuisance\x94 RA\x92s, who will not follow an RA as they have the traffic in sight, who will accept visual separation at night (day is bad enough) or very late visual switches, who think LAHSO is a good idea. USA ATC think it\x92s acceptable to \x93slam dunk\x94 a heavy jet, get shirty when foreign operators refuse a questionable clearance, literally forget about an aircraft once it has accepted visual separation. The system allows uncontrolled VFR traffic within 500ft of commercial operations which is madness.

I operated the 747-400 around the planet for over a decade, the USA was one of the most threat laden environments we went to. Lovely people, just insane procedures. In that time I experienced a TCAS RA on vectors to JFK, was sent around and put in the hold as punishment on short final in Miami for refusing LAHSO, had multiple super high workload approaches to SFO combined with the crazy policy of pairing aircraft on approach. I witnessed a Singapore aircraft being refused a diversion to Boston from JFK fifteen minutes after they stated what time they would be leaving the hold and where they would be going resulting in a fuel mayday and an unplanned diversion to a regional airport. I lost count of the times I was chastised for refusing a visual approach and visual separation in congested airspace or a very late visual switch.

On most of the planet the human is the last line of defence in a multi layered safety environment. In the USA the human is often the only line of defence, while the environment they are in is super high workload significantly reducing their capacity to trap safety issues.

Unless there is a marked attitude shift in all parties involved in aviation in the USA this will happen again, potentially quite soon.

Stay safe out there

LD
What a terrible, avoidable accident brought about by woefully inadequate procedures.
Couldn\x92t agree more with everything you say. I\x92m sure we have probably shared a flightdeck in years gone by judging by your experiences. It\x92s this kind of chaos that I have to say I miss very little!!

Subjects ATC  Close Calls  Land and Hold Short  Separation (ALL)  TCAS (All)  TCAS RA  Traffic in Sight  VFR  Visual Separation

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mahogany bob
January 30, 2025, 18:09:00 GMT
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Post: 11817487
.Night VFR / visual avoidance is difficult - above a lighted city even more difficult
it is easy to become disorientated at night particularly when making turns.

.the circling approach to r/w 33 seems demanding and pitot lookout would be focused on the runway not peripheral traffic - turns prevent all round lookout protection .

. The helo pilots could have sighted other traffic or moving lights on the ground - things happen very fast.

as stated earlier this was an accident waiting to happen - allowing VFR traffic to pass that close to traffic on short finals is crazy

with reliable engines,modern glass cockpits and brilliant nav aids flying has become a whole lot safer - mid air collisions in VFR / VMC remain high risk especially at low level if TCAS is unreliable and when weather is marginal.

the human eyeball has it\x92s limitations

PS are ATC urgent instructions ever misunderstood or not received because of comm faffs or language / regional accent misunderstandings ?


Subjects ATC  Accident Waiting to Happen  Circle to Land (Deviate to RWY 33)  TCAS (All)  VFR

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Rushed Approach
January 30, 2025, 22:19:00 GMT
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Post: 11817705
Originally Posted by Equivocal
From the comments on this thread, it seems like many are unclear about flight rules and responsibilities of pilots and ATC. I'm not suggesting that the rules are good or applied in an appropriate way but, simply, the rules are clear....even if understanding is not.
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.



Subjects ATC  Accident Waiting to Happen  IFR  Pass Behind  Pass Behind (All)  Radar  Situational Awareness  TCAS (All)  VFR

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alfaman
January 30, 2025, 22:35:00 GMT
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Post: 11817716
Originally Posted by Rushed Approach
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.
I can't speak for the USA, but my understanding was always that the flight rules for the CRJ don't change, unless the crew cancel their IFR plan: ie flying a visual approach doesn't change the flight rule status. The crew can still expect IFR separation from other IFR & SVFR flights, & traffic information on conflicting VFR flights.

Subjects ATC  Accident Waiting to Happen  CRJ  IFR  Pass Behind  Pass Behind (All)  Radar  Separation (ALL)  Situational Awareness  TCAS (All)  VFR

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canigida
January 30, 2025, 23:24:00 GMT
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Post: 11817756
Originally Posted by Rushed Approach
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.
"It's difficult to see aircraft at night against a backdrop of a city with thousands of lights." - DC isn't actually that big of a city or that brightly lit, and it seems the UH-60 was heading south west, well away from DC toward a not very dense part of suburban N. Virginia. Mostly they would see a very wide part of the Potomac river ahead, and in the distance on the western shore is a Daingerfield island (US park service land and mostly unlit), the GW parkway going N/S for a couple hundred meters (all the parkways are dangerously unlit IMO) followed by some low level typical suburb condos of a couple stories towards Potomac Yard, which other than street lights or the sign from Target is not very bright. I kayak there all the time and there's nothing much to see looking westward. I've been out of KVKX at night and can see that area and it's not dazzling.

"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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moosepileit
January 31, 2025, 01:18:00 GMT
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Post: 11817827
Originally Posted by Rushed Approach
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.
IFR, not VFR, the airliner is circling in VMC. This invalidates the following, with a lack of knowing the distict difference- that said, the conclusion is correct, it was bound to happen, the swiss cheese just had to align.

It's eerily similar to the P-63/B-17 midair- a blind collision that was instantly apparent how flawed the basic plan was, even though it had worked before.


Subjects ATC  Accident Waiting to Happen  IFR  Pass Behind  Pass Behind (All)  Radar  Situational Awareness  TCAS (All)  VFR

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Bratchewurst
January 31, 2025, 04:03:00 GMT
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Post: 11817897
Many years ago, shortly after I got my instrument rating, I flew a friend from St. Paul to St. Louis in a rented C172. Of course I filed IFR, being anxious to get more practice in the system. We were maybe 10-20 miles SW of MSP in level flight when I heard the controller tell a Northwest flight of Cessna traffic somewhere in our direction; there was another Cessna in the area as well. NW called \x93traffic in sight.\x94 Maybe 10 seconds later my passenger pointed very excitedly behind us and to our left. There was a NW 727, maybe 200-300 yards behind us and climbing through our altitude from left to right. Very fast.

I\x92ve always wondered if they really saw us or the other Cessna. It was probably the closest I\x92ve ever been to another aircraft not in the pattern. It felt way too close.

\x93See and avoid\x94 is really not the basis for safe separation of traffic in the air. Depending on it at night in airspace as busy as DC is choosing poorly.

TCAS has mostly solved the separation problem for every phase of flight except very close to the airport or on the ground. If the industry is going to short-staff ATC and keep cramming more traffic into the same airspace, the industry needs to develop and equivalent solution for those phases of flight as well.

Subjects ATC  IFR  Separation (ALL)  TCAS (All)

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