DC jet helo collision

[darthgently]

NTSB briefing.  Many unknowns but this does a good job of categorizing them.  Once they find the NV gear I think they just need to see what position the power switch is in to have a fairly good idea about the night vision context in the helo.  At very low altitude the collision avoidance just says “traffic traffic”. without advising a direction to go.   (2x speed recommended):

 

Edited February 2 by darthgently

[StrandedonEarth]

Swiss cheese model in effect:

I've heard empty seat in ATC, meaning increased workload on controllers. Chronic understaffing in ATC in general
I've heard trainee helo pilot, so instructor fell into same trap as trainee? They were probably both looking at the aircraft taking off, not noticing the CRJ. Too many lights...

[darthgently]

I keep thinking about DJI turning off the exclusion zones around airports in their drones and extreme outside possibility of any kind of positional spoofing/jamming would have been possible if the drone were very close to the helo, like hugging it as it approached the airport.  Definitely more of a Tom Clancy line of thought but probably should be considered given the implications in that airspace

[Lisias]

I was awake when this news first hit the Net, it's pretty impressive how quickly Youtube start to broadcast the videos.

IMHO people are doing he wrong questions. Doesn't really matter if he HELO's pilot were using the night googles or not, or if the CRJ copilot was doing its job on maintaining situation awareness (hint: he was).

The only question that really matters is: how in freaking hell two aircrafts were allowed to get into a collision course at first place.

How a HELO (not matter if military or not) were allowed to invade a runway's approach slope that was being in use at the moment? Why the HELO wasn't ordered to proceed to a safe (airborne) holding point and stay there until the CRJ had touched down?

Anything else is just "chover no molhado" (as we say in Brazil).

Landing airplanes "own" the space, POINT . They don't have the attitude neither the energy to do quick last minute corrections, as the CRJ sadly demonstrated. Nothing else should be allowed in her path no matter what, it's simple like that.

I would suggest to reach some civilian medevac HELO pilot and have a good chat with this guy. Few people in the World has more experience on these situations than them.

 

1 hour ago, StrandedonEarth said:

I've heard trainee helo pilot, so instructor fell into same trap as trainee?

Unlikely. Something had happened that induced the HELO pilots to do what they did. If the information I have is right, they were too high.

What would not be a problem is they were ordered to reach a safe (airborne) holding point at first place - every airport that handles helicopters have them scattered around.

For example, for night operations, the Holding Point near Congonhas Airport is over the Ibirapuera Park (and I know it because I used to have a direct vision line into it in the past, before a new building was constructed - I still have direct sigh to CGO). It's a bit far from CGO, but it's a point where the helicopters can linger without disturbing sleeping people.

[darthgently]

9 minutes ago, Lisias said:

I was awake when this news first hit the Net, it's pretty impressive how quickly Youtube start to broadcast the videos.

IMHO people are doing he wrong questions. Doesn't really matter if he HELO's pilot were using the night googles or not, or if the CRJ copilot was doing its job on maintaining situation awareness (hint: he was).

The only question that really matters is: how in freaking hell two aircrafts were allowed to get into a collision course at first place.

How a HELO (not matter if military or not) were allowed to invade a runway's approach slope that was being in use at the moment? Why the HELO wasn't ordered to proceed to a safe (airborne) holding point and stay there until the CRJ had touched down?

Anything else is just "chover no molhado" (as we say in Brazil).

Landing airplanes "own" the space, POINT . They don't have the attitude neither the energy to do quick last minute corrections, as the CRJ sadly demonstrated. Nothing else should be allowed in her path no matter what, it's simple like that.

I would suggest to reach some civilian medevac HELO pilot and have a good chat with this guy. Few people in the World has more experience on these situations than them.

 

Unlikely. Something had happened that induced the HELO pilots to do what they did. If the information I have is right, they were too high.

What would not be a problem is they were ordered to reach a safe (airborne) holding point at first place - every airport that handles helicopters have them scattered around.

For example, for night operations, the Holding Point near Congonhas Airport is over the Ibirapuera Park (and I know it because I used to have a direct vision line into it in the past, before a new building was constructed - I still have direct sigh to CGO). It's a bit far from CGO, but it's a point where the helicopters can linger without disturbing sleeping people.

A lot of these questions have been answered.  Those helos have the mission of evacuating our gov reps immediately in case of a threat to the area so are constantly on the ready and training.  They are supposed to be there on those routes and it is considered routine and worth the risk.  I’m fairly sure e we will see some modifications but I bet the training flight paths and patterns remain about the same because they have to.  I’m guessing we’ll see equipment upgrades and additional communications protocols

[Lisias]

5 minutes ago, darthgently said:

A lot of these questions have been answered.  Those helos have the mission of evacuating our gov reps immediately in case of a threat to the area so are constantly on the ready and training.

So the CRJ should had been ordered to keep a holding pattern instead, and not authorized to land at that moment.

 

6 minutes ago, darthgently said:

They are supposed to be there on those routes and it is considered routine and worth the risk.

Well, apparently some people won't agree with that anymore.

On a real threat situation in the area, no airplane would be being authorized to land there anyway. They would all be ordered to proceed to the alternates and clear the local skies. All these incoming people would add more pressure to the emergency services for starters.

See, the problem is the collision course being established - if the HELO had priority due military reasons, the CRJ should had been kicked from the landing - what would happen in a real situation anyway. How good would be a high brass evacuation mission just to have the vehicle colliding into civilian traffic?
 

7 minutes ago, darthgently said:

I’m fairly sure e we will see some modifications but I bet the training flight paths and patterns remain about the same because they have to.  I’m guessing we’ll see equipment upgrades and additional communications protocols

Someone is going to get the heat for this one - and almost surely will be a escape goat IMHO.

[StrandedonEarth]

1 hour ago, Lisias said:

. If the information I have is right, they were too high.

On the news this morning, the CRJ black box said it was at 325', while the  ATC radar had the helo reading at 200'; they were still searching for helo black box at the time. Good point about the fact that the helo shouldn't have been in the approach slope in the first place. Expanding on the empty seat at ATC, I heard there was supposed to be one ATC managing only helo's,  but with that empty seat, whoever was managing helo's was also managing fixed-wing. An apparently bad radar reading doesn't help.

Is it possible that one aircraft was using radar altimetry  (not ATC radar) while the other was using barometric altimetry, which from my (admittedly limited) knowledge wouldn't be as accurate?

E: Pilots were already complaining/stressed that there had been too many near misses in the area. When such occurrences are happening regularly, it's only a matter of time until the Swiss Cheese slices line up.

Edited February 2 by StrandedonEarth

[tater]

There are a series of flight corridors for helicopters along the river. As they mentioned in that briefing in that area near the airport, they have an altitude cap of 200 feet. The collision happened at 325ft ±25ft.

The helicopter was in the wrong place. The fact that the controllers possibly saw the helicopter altitude as 200 feet is concerning.

Even then, it would’ve been very close in vertical separation—too close—but the collision would not have occurred.

So the primary fault in my opinion would be the helicopter pilot since regardless of ATC direction, that helo should not have been >200' at all. Followed by the entire ATC system if it doesn’t accurately know the altitude of military helicopters in that area in real time.

Edited February 2 by tater

[darthgently]

24 minutes ago, StrandedonEarth said:

Pilots were already complaining/stressed that there had been too many near misses in the area. When such occurrences are happening regularly, it's only a matter of time until the Swiss Cheese slices line up.

This is actually what made the drone positioning spoofing possibility pop up in my head.  Why the rash of near collisions?  Not going TFB, just considering the remote possibility considering timing and the high value of the area to malicious actors

[magnemoe]

1 hour ago, Lisias said:

I was awake when this news first hit the Net, it's pretty impressive how quickly Youtube start to broadcast the videos.

IMHO people are doing he wrong questions. Doesn't really matter if he HELO's pilot were using the night googles or not, or if the CRJ copilot was doing its job on maintaining situation awareness (hint: he was).

The only question that really matters is: how in freaking hell two aircrafts were allowed to get into a collision course at first place.

How a HELO (not matter if military or not) were allowed to invade a runway's approach slope that was being in use at the moment? Why the HELO wasn't ordered to proceed to a safe (airborne) holding point and stay there until the CRJ had touched down?

Anything else is just "chover no molhado" (as we say in Brazil).

Landing airplanes "own" the space, POINT . They don't have the attitude neither the energy to do quick last minute corrections, as the CRJ sadly demonstrated. Nothing else should be allowed in her path no matter what, it's simple like that.

I would suggest to reach some civilian medevac HELO pilot and have a good chat with this guy. Few people in the World has more experience on these situations than them.

 

Unlikely. Something had happened that induced the HELO pilots to do what they did. If the information I have is right, they were too high.

What would not be a problem is they were ordered to reach a safe (airborne) holding point at first place - every airport that handles helicopters have them scattered around.

For example, for night operations, the Holding Point near Congonhas Airport is over the Ibirapuera Park (and I know it because I used to have a direct vision line into it in the past, before a new building was constructed - I still have direct sigh to CGO). It's a bit far from CGO, but it's a point where the helicopters can linger without disturbing sleeping people.

Agree, why fly an training flight there anyway, rather than somewhere else with no airports? Helicopters don't need airports, yes the airport might be the target of the helicopter flight but then you follow the airport orders like any small plane. 
And would understand it more had it been an medevac HELO as they has to go in anywhere and  in an hurry. 

[darthgently]

19 minutes ago, tater said:

There are a series of flight corridors for helicopters along the river. As they mentioned in that briefing in that area near the airport, they have an altitude cap of 200 feet. The collision happened at 325ft ±25ft.

The helicopter was in the wrong place. The fact that the controllers possibly saw the helicopter altitude as 200 feet is concerning.

Even then, it would’ve been very close in vertical separation—too close—but the collision would not have occurred.

So the primary fault in my opinion would be the helicopter pilot since regardless of ATC direction, that helo should not have been >200' at all. Followed by the entire ATC system if it doesn’t accurately know the altitude of military helicopters in that area in real time.

Agreed.  If they had NV on and neglected to keep their heads on swivels combined with confusing which plane they were supposed to visually pull in behind and failed to stay below the 200’ ceiling it could explain a lot.

The on board 325’ vs ATC 200’ discrepancy for the jet is a big flag of something major being off.  

In the vids the helo does appear to be maintaining a fairly constant altitude though I see random references to it rising up.  I’m not seeing the rise nor has that been reported officially.  It would seem odd for it to be at 325’ or so for an extended stretch without ATC noting the fact.  But the CJR was showing 200’, possibly erroneously, to the ATC so maybe the helo was higher and showing an erroneous 200’ also?

The CJR having a false reading of 325’ when it was actually at 200’ is the big flag right now that could crack a lot of this

[Lisias]

15 minutes ago, StrandedonEarth said:

Is it possible that one aircraft was using radar altimetry  (not ATC radar) while the other was using barometric altimetry, which from my (admittedly limited) knowledge wouldn't be as accurate?

No. At least, no if the transponder was correctly configured. Do a search about "MODE C" and "MODE S" transponders.

Additionally, TCAS relies on information given by the transponder and since the CRJ's TCAS yelled "traffic", I think both transponders were functional and correctly set up. Assuming, of course, that the CRJ's TCAS was yelling about the HELO, it's perfectly possible it would had detected something else.

Now... We have a possible conspiracy theory to contemplate by now: GPS. The transponder's Mode S relies on GPS. There must be a logical explanation for the HELO be higher than it should (if it really was higher, of course). Since is unthinkable that the HELO would be flying without transponder, we must assume that the transponder was reporting the altitude it was reading from its GPS.

If (and this is a hell of a big if) something less then ideal happened with the GPS signal, it's not impossible that the altitude could had been read wrongly, and the pilot corrected the HELO's altitude trusting this information.

BUT... Dude, we are talking about a Military HELO. It should not be easy to fool (intentionally or not) a military GPS...

 

5 minutes ago, darthgently said:

This is actually what made the drone positioning spoofing possibility pop up in my head.  Why the rash of near collisions?  Not going TFB, just considering the remote possibility considering timing and the high value of the area to malicious actors

That crossed my mind, but if any of the pilots would had been forced to deviated due flying hazards, they would had notified their respective controllers about hazards on the spot. Unless that happened in the very "sweet spot" in which the pilot would be "aviating" and "navigating" before "communicating".

I remember from one of the videos depicting both crafts' paths that the HELO apparently did a right turn "into" CRJ instead of going straight or left turning (what would had put them behind the CRJ).

The pilot must had done that for a reason.

One would be being confused about what the pilot was tracking. Other, spotting something going to hit them and reacting instinctively to avoid the collision, not realizing that the best path to avoid the imminent collision had put them into another collision route.

If this second hypothesis has teeth, the HELO's CVR will tell.

[darthgently]

5 minutes ago, Lisias said:

BUT... Dude, we are talking about a Military HELO. It should not be easy to fool (intentionally or not) a military GPS...

Agreed.  But elevation is the least accurate and most easily messed with part of a GPS lock.  And never forget Iran stealing a US military drone via GPS spoofing.  At which point they could do all the reverse engineering they wanted.  This after they already knew enough to make it land in Iran.  What else did they learn about the military tech involved? Idk.  A stretch, but I’m fairly confident that people more in the loop than I are probably examining this remote possibility

[Lisias]

45 minutes ago, magnemoe said:

Agree, why fly an training flight there anyway, rather than somewhere else with no airports?<...>
And would understand it more had it been an medevac HELO as they has to go in anywhere and  in an hurry. 

Dude, I'm avoiding thinking on this for while.

If they were, indeed, training for VIP EVAC on a crapstorm, the CRJ would be ordered to go around IMHO. On a real situation the skies would be shut as it happened on 911 - everybody flying would be ordered to leave the area or be shot down.

Or they would be training for a silent evacuation, in which VIPs would be evacuated without alarm or warning for the general population - but that is a very dark path to go into.

1 hour ago, StrandedonEarth said:

Good point about the fact that the helo shouldn't have been in the approach slope in the first place.

IMHO, this is the cause of the accident. Everything else are just contributing factors.

Edited February 2 by Lisias
Completing a line of thought.

[tater]

54 minutes ago, Lisias said:

IMHO, this is the cause of the accident. Everything else are just contributing factors.

Yes.

I don't buy the altitude for the CRJ being off by that much, they were on short final, being 100-150' low that close seems incredibly unlikely, they have visual cues for glide slope (PAPI).

[JoeSchmuckatelli]

2 hours ago, magnemoe said:

ly an training flight there anyway

Military aircraft.  Every flight outside of combat is a training flight. 

Don't let different community lingo confuse that this is weird or out of the ordinary. 

Looking like a simple, tragic error. 

 

Edited February 2 by JoeSchmuckatelli

[Lisias]

51 minutes ago, tater said:

I don't buy the altitude for the CRJ being off by that much, they were on short final, being 100-150' low that close seems incredibly unlikely, they have visual cues for glide slope (PAPI).

And even if they were that low, the whole system is designed to allow pilots to make mistakes or do unplanned corrections or changes without killing themselves, there're always margins for errors on everything.

So allowing traffic under a landing craft is plain unthinkable no matter what.

Merely flying over a taxing/holding craft on an airport is considered a near miss incident and kicks a FAA investigation (see the now iconic incident with American Airlines Flight 1456 and an Aviat Husky in John Wayne Airport in 2017).

 

[tater]

2 minutes ago, JoeSchmuckatelli said:

Looking like a simple, tragic error. 

Yeah—by only concern would be that there was not some system in place near DCR to make sure any helo is in that corridor for any routine operations (which includes routine training). That has to be possible for a $6M+ vehicle.

2 minutes ago, Lisias said:

And even if they were that low, the whole system is designed to allow pilots to make mistakes or do unplanned corrections or changes without killing themselves, there're always margins for errors on everything.

So allowing traffic under a landing craft is plain unthinkable no matter what.

Merely flying over a taxing/holding craft on an airport is considered a near miss incident and kicks a FAA investigation (see the now iconic incident with American Airlines Flight 1456 and an Aviat Husky in John Wayne Airport in 2017).

 

100%.

Like I said, it's still a near miss incident, even if the Blackhawk was not grossly higher than allowed—but then it's a near miss incident, not an airliner of dead people.

I saw a post from a Navy Seahawk guy who said they flew everywhere near the carrier at 150' to deconflict with aircraft though.

Better would be for that "Route 4" to be at least 1000' under final—which means flying away from the river a decent distance. That of course carries its own risk, now the low flying helos are over people's houses, etc.

Alternately, within some range they simply have to act like every other aircraft, and let ATC tell them where to go.

[JoeSchmuckatelli]

3 minutes ago, tater said:

Yeah—by only concern would be that there was not some system in place near DCR to make sure any helo is in that corridor for any routine operations (which includes routine training). That has to be possible for a $6M+ vehicle.

Presume any altitude under 200 is open for the helo. 

If there was a maintenence {or training) issue with the altimeter {or crew} - that's an unfortunate error - aka negligence. 

If the plane pilot was lower than recommended that would be contributing negligence. 

Sadly I worked for years in the industry that deals with tragic accidents. 

It's usually some form of incompetence / negligence that causes the most tragic things - and while human to seek for a cause or to try to eliminate accidents from ever happening... Something inevitably goes wrong (given sufficient time / opportunity) 

[StrandedonEarth]

Ok, I should have posted links earlier. I had trouble finding the Global News clip where they talked about altitudes, I guess they were showing a clip from other news agencies. I did find this, https://www.usatoday.com/story/news/nation/2025/02/02/helicopter-airplane-collision-dc-updates/78154023007/ , which is probably where the info came from that ATC radar showed the HELO at 200' (some posters mis-parsed my post and thought I said radar showed the CRJ (jet) at 200', and the error propagated). To re-iterate, per the previous link, the jet's black boxes showed the jet at 325' and pitching up, and the pilots "verbal reaction (presumably cursing). Reportedly, but not confirmed, ATC radar showed the HELO at 200', but obviously it was not. This clip https://globalnews.ca/video/10992669/dc-plane-crash-how-the-black-boxes-will-help-investigators-piece-together-final-moments/ talks about changes to helo flight paths following the accident.

[Lisias]

1 hour ago, JoeSchmuckatelli said:

Presume any altitude under 200 is open for the helo.

As long it doesn't crosses an approach slope!

 

1 hour ago, JoeSchmuckatelli said:

If there was a maintenence {or training) issue with the altimeter {or crew} - that's an unfortunate error - aka negligence. 

Unless some exigent circumstance had happened.

 

1 hour ago, JoeSchmuckatelli said:

If the plane pilot was lower than recommended that would be contributing negligence. 

Unless some exigent circumstance had happened.

 

1 hour ago, JoeSchmuckatelli said:

It's usually some form of incompetence / negligence that causes the most tragic things - and while human to seek for a cause or to try to eliminate accidents from ever happening... Something inevitably goes wrong (given sufficient time / opportunity) 

The devil is on the details. People are usually scared to death from big problems, but what really kills you (most of the time) is a loose bolt, a stripped screw jack, the wrong grease in the gear, wiring problems or too much dirty in the sparks.

Spoiler

(or something idiot from the marketing department dictating how to implement security features in the software to maximize income)

 

 

[darthgently]

48 minutes ago, StrandedonEarth said:

Reportedly, but not confirmed, ATC radar showed the HELO at 200', but obviously it was not.

The NTSB presser I opened this thread with confirms this solidly.  And it isn’t obvious to them yet.  They are still trying to determine the actual altitude of collision is what I got

 

[K^2]

1 hour ago, JoeSchmuckatelli said:

Presume any altitude under 200 is open for the helo. 

Every indication - visual recordings, recovered altimeter data, and radar data, suggest helo went over 200'. It's unclear if they had a reason to or if this was a mistake at this point, but that looks to be one of the factors in the accident.

1 hour ago, JoeSchmuckatelli said:

If the plane pilot was lower than recommended that would be contributing negligence. 

Looking at the approach, if the liner went below 200' at that point, it was not on a slope to land at the airport. Since it was established, I assume the plane was on ILS slope. There is not really a whole lot the crew of the airliner could have been doing differently than they did following their ATC clearance.

All of this said, if the plane passed 100' over the helo, the latter would still be caught in a wash with potentially tragic consequences for the latter. So while the altitude might have contributed to the direct crash, causing the loss of the airliner, the situation where the two flight paths were allowed to cross with less than 500' of vertical separation (which was simply unavailable) should never have been allowed in the first place.

As far as I can tell, the crew of the airliner made no mistakes. Their warning systems would have been useless in congested airspace, and they would be landing with nose-up attitude and slight left bank, meaning they couldn't possibly see the helicopter, and would be relying on ATC to make sure their landing path is clear.

The helo was given a directive to maintain visual separation, which they failed to do. What I have no idea about, and I hope the investigating team sorts out, is whether that was a reasonable request in the first place, whether the helo crew would have been expected to follow such a request or should have protested, and why visual separation is even part of the procedure in such a congested space. This could place responsibility on any combination of the helo crew, ATC, and the airport admin. It is entirely possible that everyone did what they were supposed to, and the procedure was just bad. But usually, accidents like this happen when multiple things go wrong, and that's probably the case here.

[tater]

16 minutes ago, K^2 said:

Looking at the approach, if the liner went below 200' at that point, it was not on a slope to land at the airport. Since it was established, I assume the plane was on ILS slope. There is not really a whole lot the crew of the airliner could have been doing differently than they did following their ATC clearance.

Yeah, if they're where the helo should have been, they're taking a swim. Incredibly unlikely, and NTSB seems confident in the alt to ±25 ft, so the Blackhawk was 100% in the wrong place. ATC didn't vector them into the CRJ, and they had an altitude cap, the fault lies entirely with the helicopter pilot, IMO.

Is it possible the accident could have been prevented by better ATC? Sure. Would better overall procedures in that crowded, constrained airspace have prevented it? Absolutely.

I see no fault but whoever was flying at that time. Do we know who that is yet? (surely NTSB knows)

[K^2]

39 minutes ago, tater said:

Yeah, if they're where the helo should have been, they're taking a swim. Incredibly unlikely, and NTSB seems confident in the alt to ±25 ft, so the Blackhawk was 100% in the wrong place. ATC didn't vector them into the CRJ, and they had an altitude cap, the fault lies entirely with the helicopter pilot, IMO.

ATC told them to maintain visual separation and to remain East of CRJ. Given how many planes there were in the air (you can see this on footage from a number of angles) I'm not sure it was reasonable to expect that helo had a fix on the correct plane. And if they believed that they were given a fix on a plane ahead of AA5342, then they were flying exactly as vectored. In other words, they proceeded on the course they had in their plans which would bring them directly under the landing airliner, well within the wash.

Again, the only deviation from helo was the altitude, and while maintaining 200' would have saved the airliner, it would not prevent an incident with the helo, potentially with the loss of its crew. The vectors they got from ATC did not prevent the approach far below the minimum allowed separation.

The incident turned into an accident turned into a catastrophe due to helo exceeding altitude, but the situation shouldn't have existed in the first place. The vectors helo got from ATC were not adequate for the situation. That is not even a question.

The question is whether this was because ATC didn't follow the procedure, helo crew didn't request better vectors, or both did what they were supposed to and the procedure was just bad. This is really the extent of the unknowns at this point.