PSA CRJ-700 AA midair collision

derg said:
When it comes down to it, in my opinion, there probably shouldn’t be a helo corridor that close to that circle to land runway at DCA.
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As a layperson who is speculating circumstantially, I do wonder from a chicken or the egg standpoint whether the helo route came first or the circle to land runway 33 came first.

The helo route looks like it would deconflict helicopters and fixed wing so long as DCA was using runways 1/19 only in a north south configuration, because the aircraft on approach would be fairly high by the time the route crosses the extended center lines.

It’s been said elsewhere in this thread that the circle to land runway 33 gained popularity with RJs due to the same runway separation vs intersecting runway separation ATC rules being more favorable to packing traffic closer together on intersecting runways - same exception that is used to the advantage of places like LGA, SFO, etc.

I wonder if it’s a case of helo route was there first before the circle was widely used? If so, could be fixed by saying “helo route NA when circle Rwy 33 in use.”
 
derg said:
Thanks.

However, it’s a poor mix of traffic even in

(Hot damn, I’m on break and it just got turbulent, WTF are those two dudes doing up there, looking for clouds to run into? :) )

… day VMC. Spotting traffic, and the right traffic, at night is challenging at congested airports and we’ve had a large number of people seeing the wrong aircraft at other airports.

TCAS is dated, yes, but even if we shift to a system where we can have RAs below 1000 feet or even software that predicts conflicting paths during maneuvering would probably make the system worse., take ATL when all three landing runways are running parallel operations - by merely turning base it’s going to scatter aircraft like going pspspspsps to a bunch sleeping cats.
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That’s where the learning algorithms have to be included in the simulation modeling.

DARPA has already demonstrated this. And yes a big part of this is teaching the drones to stay away from the slower meat processed airspace participants, but damn if we haven’t had a host of demonstrations in the last 10 days saying maybe the human eyeball and the scan/processing of said eyeball isn’t doing it anymore.

Making procedural change is easy, but if we slap the table as “problem solved” to miss the forest for that one tree we’re gonna be right back here trying to figure out if the tourism helicopter or air ambulance route or random Amazon drone path needs reworked one at a time until we find all the conflicts through attrition.


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inigo88 said:
As a layperson who is speculating circumstantially, I do wonder from a chicken or the egg standpoint whether the helo route came first or the circle to land runway 33 came first.

The helo route looks like it would deconflict helicopters and fixed wing so long as DCA was using runways 1/19 only in a north south configuration, because the aircraft on approach would be fairly high by the time the route crosses the extended center lines.

It’s been said elsewhere in this thread that the circle to land runway 33 gained popularity with RJs due to the same runway separation vs intersecting runway separation ATC rules being more favorable to packing traffic closer together on intersecting runways - same exception that is used to the advantage of places like LGA, SFO, etc.

I wonder if it’s a case of helo route was there first before the circle was widely used? If so, could be fixed by saying “helo route NA when circle Rwy 33 in use.”
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I am about 90% certain LGA does not mix arrivals and departures on the same runway unless they are single runway ops. They land on whatever runway is most favorable to the wind and they depart the other, so it is not exactly an apples to apples comparison. Additionally, the only helicopter route in the vicinity goes directly overhead the field, roughly perpendicular to the runways so they are no where near an approach.
 

View: https://youtu.be/lJmvyEEIkEM?si=myyZSr2L7gLhN9cg




Austin is good people. I know we were knocking podcast experts, but I’ll vouch for him not just being some online personality in for his 2 cents and click traffic. He is very seriously trying to understand what happened up there without stepping into the lane of safety center jd NTSB and willing to provide himself to public speculation on his intentions which is pretty admirable. The only fault I can give him is the speed at which he drank the Hawk kool-aid when all he talked about before selection was flying Attack.

I wasn’t aware he retired out of there, but he goes very well into the nuances of operations in that Area and does a rely good job discussing the Army speak and lingo in a way any layman much less any aviator can understand. Also explains a lot of the cultural realities of the mission that unit performs and the people performing it.


His statements on procedures and standards as well as systems peculiarities of the airframe vs what NTSB statements are saying go a very good way toward explaining away a lot of the first moment assumptions that came out of this incident.


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MikeD said:
You know you’d have the idiot crew that would fly the plane into the ground because the RA told them to.
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Wait, let me put my 350 lanyard back on.

People hand-fly RA’s? :)

IMG_0682.jpeg
 
derg said:
(Hot damn, I’m on break and it just got turbulent, WTF are those two dudes doing up there, looking for clouds to run into? :) )
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I won't lie, I miss the bunk room being mixed up with some moderate turbulence "back in the day"; I got some of the best sleep of my life during those breaks. :)


 
GolfChuck said:
I am about 90% certain LGA does not mix arrivals and departures on the same runway unless they are single runway ops. They land on whatever runway is most favorable to the wind and they depart the other, so it is not exactly an apples to apples comparison. Additionally, the only helicopter route in the vicinity goes directly overhead the field, roughly perpendicular to the runways so they are no where near an approach.
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Agree and neither does my other example SFO, so maybe I’m misunderstanding how DCA uses the circle to land runway 33 to their advantage.

My understanding was that there was a departure on runway 1 prior to PSA, and that tower changed PSA to the circle to land runway 33 to reduce the separation required from same runway separation rules (3000/4500/6000 ft, wake turbulence if applicable, I’ve heard of RECAT but I don’t totally understand it yet, etc) to intersecting runway rules (which I understand to be basically will the intersection be clear when the arrival passes the runway threshold). I’m not a controller so I’m referencing 7110.65 3-10-3 and 3-10-4, if that’s even the right place to look. If DCA’s usage of runway 1 vs runway 33 is more nuanced than that, I’m interested to learn. :)

As far as the helo route crossing the extended runway centerline, I was again referring to DCA and not LGA.

If you compare the distances on the DC Helicopter Route Chart between the runway 33 threshold to route 4 (red line) and the runway 19 threshold and route 1 near the Jefferson Memorial (yellow line), you can see the yellow line is quite a bit longer and thus there would normally be more vertical separation between a runway 19 arrival and a helo on route 1/route 4. If runway 1 is in use it’s even less of an issue because departures are climbing more steeply than a 3 degree glideslope so there would be even more vertical separation. To me that looks like the route 1/route 4 corridor was designed to deconflict helicopters on the east side of the Potomac with DCA traffic so long as DCA is in a runway 1 or runway 19 configuration, but once runway 33 is in use all bets are off.

IMG_6133.jpeg


Hopefully that clears up my previous comment!
 
inigo88 said:
Agree and neither does my other example SFO, so maybe I’m misunderstanding how DCA uses the circle to land runway 33 to their advantage.

My understanding was that there was a departure on runway 1 prior to PSA, and that tower changed PSA to the circle to land runway 33 to reduce the separation required from same runway separation rules (3000/4500/6000 ft, wake turbulence if applicable, I’ve heard of RECAT but I don’t totally understand it yet, etc) to intersecting runway rules (which I understand to be basically will the intersection be clear when the arrival passes the runway threshold). I’m not a controller so I’m referencing 7110.65 3-10-3 and 3-10-4, if that’s even the right place to look. If DCA’s usage of runway 1 vs runway 33 is more nuanced than that, I’m interested to learn. :)

As far as the helo route crossing the extended runway centerline, I was again referring to DCA and not LGA.

If you compare the distances on the DC Helicopter Route Chart between the runway 33 threshold to route 4 (red line) and the runway 19 threshold and route 1 near the Jefferson Memorial (yellow line), you can see the yellow line is quite a bit longer and thus there would normally be more vertical separation between a runway 19 arrival and a helo on route 1/route 4. If runway 1 is in use it’s even less of an issue because departures are climbing more steeply than a 3 degree glideslope so there would be even more vertical separation. To me that looks like the route 1/route 4 corridor was designed to deconflict helicopters on the east side of the Potomac with DCA traffic so long as DCA is in a runway 1 or runway 19 configuration, but once runway 33 is in use all bets are off.

View attachment 82326

Hopefully that clears up my previous comment!
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Without using the circle to 33, DCA is basically a single runway airport. By utilizing the circle, they can have departing traffic line up and wait on 1. As soon as the landing traffic clears the intersection, they clear the departing traffic for takeoff. When landing traffic doesn’t circle to 33 (for a variety of reasons), it’s common for the tower controller to clear a departing aircraft to line up and wait and also tell them to be ready for an immediate departure. Before you can even get the thing lined up on the centerline, tower is clearing you for takeoff and advising traffic is on a 2-2.5 mile final. Basically, they have been trying to fit 10 lbs of poo in a 5 lb bag for years.
 
guywhoflies said:
Without using the circle to 33, DCA is basically a single runway airport. By utilizing the circle, they can have departing traffic line up and wait on 1. As soon as the landing traffic clears the intersection, they clear the departing traffic for takeoff. When landing traffic doesn’t circle to 33 (for a variety of reasons), it’s common for the tower controller to clear a departing aircraft to line up and wait and also tell them to be ready for an immediate departure. Before you can even get the thing lined up on the centerline, tower is clearing you for takeoff and advising traffic is on a 2-2.5 mile final. Basically, they have been trying to fit 10 lbs of poo in a 5 lb bag for years.
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Awesome, that matches my understanding too.

Is there ever a case where they do the opposite? Clear an RJ for takeoff on runway 33 while there’s a 737/Airbus on a 2.5 mile final for runway 1? That would be a little more “dynamic” than some of the other examples we were talking about like SFO, LGA, MDW etc where there’s generally advertised arrival runways and departure runways that don’t change. I imagine if they switch off like that for whatever is most operationally efficient for them based on the traffic they have at that moment: (departure on 1, arrival on 33) vs (arrival on 1, departure on 33) then you must really have to be on your toes.
 
inigo88 said:
Awesome, that matches my understanding too.

Is there ever a case where they do the opposite? Clear an RJ for takeoff on runway 33 while there’s a 737/Airbus on a 2.5 mile final for runway 1? That would be a little more “dynamic” than some of the other examples we were talking about like SFO, LGA, MDW etc where there’s generally advertised arrival runways and departure runways that don’t change. I imagine if they switch off like that for whatever is most operationally efficient for them based on the traffic they have at that moment: (departure on 1, arrival on 33) vs (arrival on 1, departure on 33) then you must really have to be on your toes.
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Absolutely. They sometimes offer 33 for departure to RJs with something along the lines of, “You will get out sooner.”
 
If San Diego can function with one runway, why can't DCA? You just need to get rid of the regional jets and use bigger airplanes.
 
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