January 30, 2025, 07:59:00 GMT
permalink Post: 11816973
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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January 31, 2025, 01:18:00 GMT
permalink Post: 11817827
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.
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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January 31, 2025, 17:13:00 GMT
permalink Post: 11818379
Heathrow is great, calm and polite.
Even as they apologize for setting up a near miss, they are, polite and calm.
They are human, and subject to the same frailties as the rest of us.
They are sure polite though.
Heathrow suffers from the problem that their local airspace is.. logical, as are the flight paths, and generally the runway utilisation. They don't have the benefit of the special design skills applied to JFK's terminal procedures which seem to have been designed to give cardio workouts for the controller and the pilots. Masterful airspace design.
JFK, making Abuja look attractive.
Even as they apologize for setting up a near miss, they are, polite and calm.
They are human, and subject to the same frailties as the rest of us.
They are sure polite though.
Heathrow suffers from the problem that their local airspace is.. logical, as are the flight paths, and generally the runway utilisation. They don't have the benefit of the special design skills applied to JFK's terminal procedures which seem to have been designed to give cardio workouts for the controller and the pilots. Masterful airspace design.
JFK, making Abuja look attractive.
Re-stated I being the target being "seen" would be thinking "Is it for sure me he is seeing?" and I would be looking for him to make darn tooting I
KNEW
where the conflicting traffic was as ATC thought it to be a conflict.
I learned that from during my Student Pilot days and it was reaffirmed till I retired from flying.
The Rule is "see and be seen"....which I read as being a two way street kind of situation.
When there is doubt...there is no doubt....remedy the situation as quickly and safely as possible.
If your aircraft is so complex and difficult to fly, or your procedures do not require or allow you to look out when appropriate, and that one of you cannot be spared to take a look out the window now and then....or if you think there is no need for you get your scan outside because you think yourself too busy inside.....there is something close to home that warrants changing.
Bottom line....nothing prevents you from doing a "missed approach" and give it a second try if it eliminates a critical risk of some kind. Even Air Line Pilots do not have to land on every approach and need to kick the mindset every second counts and remind their management that an occasional delay's expense is far cheaper than an accident. It also might make the difference between being retired and enjoying life and just being another statistic or name on a list of those killed In a crash.
This discussion about who is burdened with the responsibility for traffic separation between ATC and Pilots omits one thing.....the PIC of each aircraft is equally responsible for the safety of their own aircraft. More importantly, ATC Controllers might have to live with their mistakes but Pilots die by theirs.
I learned that from during my Student Pilot days and it was reaffirmed till I retired from flying.
The Rule is "see and be seen"....which I read as being a two way street kind of situation.
When there is doubt...there is no doubt....remedy the situation as quickly and safely as possible.
If your aircraft is so complex and difficult to fly, or your procedures do not require or allow you to look out when appropriate, and that one of you cannot be spared to take a look out the window now and then....or if you think there is no need for you get your scan outside because you think yourself too busy inside.....there is something close to home that warrants changing.
Bottom line....nothing prevents you from doing a "missed approach" and give it a second try if it eliminates a critical risk of some kind. Even Air Line Pilots do not have to land on every approach and need to kick the mindset every second counts and remind their management that an occasional delay's expense is far cheaper than an accident. It also might make the difference between being retired and enjoying life and just being another statistic or name on a list of those killed In a crash.
This discussion about who is burdened with the responsibility for traffic separation between ATC and Pilots omits one thing.....the PIC of each aircraft is equally responsible for the safety of their own aircraft. More importantly, ATC Controllers might have to live with their mistakes but Pilots die by theirs.
DCA, and others nornalize collision alerts in the background of a significant % of ATC transmssions.
TCAS RA heights show mandatory Day, VMC go arounds the day prior- but how close was the helicopter to the 737 not going around 2 minutes earlier the day prior, so low TCAS TA only height below 900' allows continuing?
You think the CRJ crew, below 500', rolling out of a left turn to 33 sees the helicopter to their right or even notices the TCAS TA display? Maybe it gets a glance IF the short final is wired. Problem is the Traffic aural is already expected in the airspace, same as hearing the ATC collision alarms in their transmission background.
There will be line of sight recreations in the reports. The CRJ will not have but a scant chance to have seen the PAT25, with caveats- the CVR has to be heard.
Pat25 likely had a 500 hour pic getting a checkride in the right, distant seat and the radio PM/1000 hour pilot in left seat, seeing only AAL3130 and trying to figure out how to pass behind, cognitive dissonance with what is seen..
3 seconds later, all ends.
James Reason, Diane Vaughan, NASA, et al...
Subjects
ATC
CRJ
Close Calls
DCA
PAT25
Pass Behind
Pass Behind (All)
Separation (ALL)
TCAS (All)
TCAS RA
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February 01, 2025, 15:17:00 GMT
permalink Post: 11819090
200 ft is not the separation between the 2 aircrafts, it's the maximum altitude allowed in the helicopter corridor. As the airplane on approach is supposed to be at about 250 ft when crossing this corridor, there is no way a 200 ft separation could ever have been achieved.
500' is also the VFR and IFR vertical offset standard. If unable to achieve, should not be allowed. 200' leg must be to be 500' below south flow DCA departures, so North flow arrivals need a better gate.
Subjects
DCA
IFR
Separation (ALL)
TCAS (All)
TCAS RA
VFR
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February 07, 2025, 00:07:00 GMT
permalink Post: 11823327
On a 300'/mile 3 degree vertical path, landing 33 traffic is FAR below 700', or 500' vertically above the 200' Route 1/4 top. Vertical separartion does not exist. Lateral failed.
Route construction error, if 33 landings were mathed. Route restriction error if the "rules" in the letter of agreement of ATC/FAA and DoD users nailed the brass tacks.
Tragic that the helo was high, but the foul is being there with traffic crossing. South flow DCA departures might be allowed, but a V1 cut and it's low screen height/TERPS/reduced climb gradient would deem consideration.
RWY 1 gives far more clearance, in all conditions.
Subjects
DCA
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February 07, 2025, 03:43:00 GMT
permalink Post: 11823374
Without context. Helo below the jet only sounds good, it follows no actual vertical separation standards/procedures/rules.
The CRJ was given the right of way by ATC, who did not control the conflict. All lateral issues, because the vertical does not matter until more than 500' separation can be maintained. Even at 200', the helo was in the CRJ's airspace in all 4 dimensions.
The CRJ was given the right of way by ATC, who did not control the conflict. All lateral issues, because the vertical does not matter until more than 500' separation can be maintained. Even at 200', the helo was in the CRJ's airspace in all 4 dimensions.
Subjects
ATC
CRJ
Separation (ALL)
Vertical Separation
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February 07, 2025, 12:37:00 GMT
permalink Post: 11823616
1.5NM is obviously not applied, look at the south flow arrivals TCAS RA the day prior. It, a PAT merged previously with a SWA 737 at TCAS TA altitudes with Collision Alert to ATC radar, before causing the later RA.
Last edited by moosepileit; 7th February 2025 at 15:53 .
Subjects
ATC
Radar
Separation (ALL)
TCAS (All)
TCAS RA
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February 07, 2025, 15:59:00 GMT
permalink Post: 11823731
1.5Nm is longer than Rwy 1. Any traffic on the runways basically knocks out helicopters within a circle more or less encompassing Memorial Bridge, Capitol St Bridge, the sewage treatment plant, and Route 5. The approach paths to the two runways are pretty close together compared to a 1.5Nm separation.
Anything approaching Rwy 1 should be below ~700ft anywhere north of the sewage treatment marker; use the Wilson Bridge for a bit of headroom because not all aircraft are going to be perfectly on glideslope.
The river is far narrower than 1.5Nm so clearly a southbound helicopter on Route 4 can never cross a northbound aircraft approaching runway 1 north of the Wilson Bridge.
You'd have to hold a southbound helicopter north of either the Memorial or Capitol St Bridges until previous traffic had landed. Then have a sufficiently large gap with no arrivals (or departures until south of the runways) for the helicopter to reach the Wilson St Bridge before the next arrival crosses that bridge.
That's the preceding aircraft covering ~3Nm at 140kt (~80s), followed by the helicopter covering ~6Nm at ~100kt (another 3.5min), and accurately timing the next arrival so it doesn't cross the Wilson bridge until after the helicopter, or it needs to do a go-around.
Anything approaching Rwy 1 should be below ~700ft anywhere north of the sewage treatment marker; use the Wilson Bridge for a bit of headroom because not all aircraft are going to be perfectly on glideslope.
The river is far narrower than 1.5Nm so clearly a southbound helicopter on Route 4 can never cross a northbound aircraft approaching runway 1 north of the Wilson Bridge.
You'd have to hold a southbound helicopter north of either the Memorial or Capitol St Bridges until previous traffic had landed. Then have a sufficiently large gap with no arrivals (or departures until south of the runways) for the helicopter to reach the Wilson St Bridge before the next arrival crosses that bridge.
That's the preceding aircraft covering ~3Nm at 140kt (~80s), followed by the helicopter covering ~6Nm at ~100kt (another 3.5min), and accurately timing the next arrival so it doesn't cross the Wilson bridge until after the helicopter, or it needs to do a go-around.
Hence the issue requiring metering the helicopters on the numbered Routes.
I don't suggest a hard 1.5NM, but anywhere standard fixed wing ops cannot assure 500' vertical separation, Rotary wing traffic must be gated and controlled.
If rotary wing mission dictates, then fixed wing traffic will have to wait/go missed/discontinue approach. Visual Sep, ATC and a Pavlovian environment killed an airliner.
Subjects
ATC
Route 4
Route 5
Separation (ALL)
Vertical Separation
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February 18, 2025, 11:48:00 GMT
permalink Post: 11830679
But, who exactly are the \x93knuckleheads\x94 ? To my mind, they are the officials who approved these routes & procedures. Would you agree ? Others (ATC & pilots) might have made contributory errors, but the situation was orchestrated by those who designed & allowed the procedures. Correct ?
How do you boil a frog? Just like this. Obe degree at a time. This is the B-17/P63 crash- dumb orchestration, no one spoke up.
Subjects
ATC
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March 18, 2025, 23:32:00 GMT
permalink Post: 11849879
Normal aviation math is neither hard, nor political.
Not sure if the Blancolirio link has been posted yet, but just in case, he's got a useful summation:
https://www.youtube.com/watch?v=QotAE0UTZJk
Subjects: None
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April 22, 2025, 17:27:00 GMT
permalink Post: 11871694
Like the 2022 P-63/B-17 midair in Texas to the warbird airshows or space shuttle losses- bright lights on and microscopes out, after the bloodspill, we all see the issues that existed over generations.
Boiled frog syndrome- frog jumps out of boiling water, but simmers to death if you raise a warm pot over enough time.
Safety first, right behind comfortable, scheduled profit. Where's the next one we can stop?
Boiled frog syndrome- frog jumps out of boiling water, but simmers to death if you raise a warm pot over enough time.
Safety first, right behind comfortable, scheduled profit. Where's the next one we can stop?
Subjects: None
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