Critical safety systems, and obviously ATC and controlled airspace is one of them (especially Class B airspace) are all designed so that one ****-up doesn't get people killed.  It requires at least two and usually three or more for a bad thing to happen.

Obviously, even without all the facts, at least two ****ups did happen because all the people involved are dead and two hulls went in the water in pieces.

The "public" Flight Aware track is all over the place of course but the helo was not on it -- it was running under VFR and was a military chopper.  However, since it is transiting said Class B space it is under ATC control and it is their job to not have two things in the same piece of air at the same time.

That's ATC's first, second, third and last job.

This sort of flight in general incidentally is not uncommon around DC so spare me the "oh someone flew into whatever on purpose" bull**** until and unless you have hard evidence; if you've spent any time in DC you know damn well that it is very busy airspace and chopper traffic is part of it.  But there are specific routes for choppers and in that area the hard ceiling is 200' with de-conflicting being one of the prime reasons for that as runways have standard approach plates (with descent angles) and thus vertical separation at defined points for an aircraft on said descent.

This is one full minute before the collision and likely was the case long before that but I don't have the data (that's from Massie's post) going back further in time:

This is what is known at the point I pen this and post it:

• The CRJ was on approach to runway 33, having been asked if they could take 33 and had accepted it.  They were configured for touchdown and from where the impact occurred I'd hazard a guess they were under 20 seconds from the runway threshold.  Best guess is the collision occurred about a half-mile out and at ~120mph, a reasonable approach speed, you'd be ~15 seconds from the runway threshold.  You can't pull serious evasive maneuvers in that situation and configuration; there's nowhere to go and the aircraft is not configured in a fashion where you can get immediate and safe evasive response anyway.  You can go around, however, and in fact that is planned as a possible event and thus there is a clear path allowed for it if you miss the approach before you're cleared to land originally.
  
  
• The aircraft's TCAS almost-certainly did not alert for multiple reasons (not the least of which is that it doesn't run at very low altitude because it might otherwise tell you to fly into a building!) never mind that the chopper either didn't have one or had its ADS-B transponder (if it had one on board) off.
  
  
• The helo essentially flew into the descending plane's path, crossing the approach path to the runway, and by the tower data which we have the trace for was above the hard ceiling for the route it was on and thus the collision occurred.
  
  
• The two pilots in the chopper were running a training flight; one had 1,000 hours and the other 500.  What the hell is anyone doing running training flights in some of the most-congested airspace in the world and by the way while 1,000 or 500 hours isn't exactly "green" its not all that much either.  A commercial captain typically requires 5,000 hours of flight time to earn that left seat!  These two in the chopper had one third of that between the two of them and had no damned business running training operations at night in what is one of the busiest commercial airspaces of the world.  This goes directly to the helo's apparent violation of the hard ceiling for helicopter operations in that area.  The pilots in the helo appear, from the data, to have violated the corridor they were required to stay inside of for safe operation.  In addition from the data on their altitude at impact there were also wildly out of the corridor horizontally; they had to be in order to hit the plane at that altitude as the corridor is designed explicitly to provide safe clearance from flights on approach or departure up to its ceiling.
  
  
• At night the aircraft probably could not see the helo as its nav and anti-collision lights are on the lower part of the fuselage and the plane's windshield does not go to the floor, so the pilots have limited or no visibility below them in a close-quarters situation.  Never mind that their attention is properly on the approach because they (with good cause) assume ATC is responsible for separation of other aircraft in the immediate area being Class B airspace -- unlike the pilots ATC sees it all from the tower radar and transponder receivers and thus has course, identification and altitude on the scope for everything in the area of the airport.
  
  
• It is claimed the helo called back to ATC with "traffic in sight" -- which was obviously not the case as they flew right in front of the plane that was descending on top of them.  They clearly were looking at the wrong aircraft (or lying -- and we had better not find out that was the case.)  ATC had knowledge that they'd done nothing to deviate their course as there was no immediate directional or altitude change on their scope and their scope showed that the two were on a collision course and the helo was above the hard ceiling for that area.
  
  
• Both the helo and aircraft run on different frequency bands thus both can hear the tower on their respective frequencies -- but not each other.

There have been a bunch of near-miss events that were reasonably-traceable to ATC in the last few years and I will remind you the FAA has made a big deal about hiring even profoundly disabled people for ATC duty, which incidentally is ****ing stupid.

Oh by the way the FAA claimed on September 23 of last year it had met the goal of hiring and training the required number of controllers so why was that tower running without proper staffing levels?

Was that lie -- simply put, there was a lack of appropriate competence despite the FAA's claim of just a few months ago -- a factor here?  It is not yet known and probably won't be for a while but that the ATC tower system had the conflict on scope with plenty of time to prevent the collision is, at this point, known fact -- that data clearly shows that the system alerted on the conflict in plenty of time for the collision to be avoided.  Further, and far worse as noted above the scope showed that the helo was outside of its authorized flight corridor operating envelope both horizontally and vertically which meant conflict or not where was the ATC demand to the helo long before it could hit anything to get its rotary-wing ass back inside the corridor or the get the Hell out of their Class B airspace?

By the way if you fly into unauthorized airspace generally you get a nice "request" to call a specific number when you land and there is a serious ass-chewing and quite-possibly ticket-punching on your license that is about to be served on you as a result.  So where was that eh since its quite-clear the helo pilot was outside the authorized operation corridor.

Again the AP is reporting that the FAA has said the tower was running without normal staffing levels and specifically, that one controller was handling both fixed wing and helicopter traffic.  This is absolutely unacceptable and ridiculously unsafe in busy airspace because the two use different frequencies; choppers are usually on UHF where aircraft are typically in VHF and as a result when you key up to talk to one you cannot hear the other for a brief time, never mind expecting even a competent person to be able to keep more workload straight than is reasonable where ****-ups will kill people in size.

In short we now know that ATC had on their scope the conflict with plenty of time to resolve it and that the helo was both above the ceiling and too damn close (thus inside the approach path!) yet no order was given to get the **** out of the controlled space to said helo and while there apparently was an exchange asking if they had the inbound in sight and confirmed they did and would pass behind it the fact remains that the helo, by the data, was above the hard ceiling, not in the narrow approved corridor by the far bank and ATC had a conflict indication on their scope with plenty of time to deconflict the situation before the collision occurred yet no deviation in the helo's flight path was seen on said scope.

When you add to this not having proper staffing which we can charge directly to the FAA as they have a decade-long reported refusal to hire thousands of qualified white people for the job -- a refusal that is illegal since discriminating based on race is against the law and you have all the ingredients -- even if the controller is competent he or she was deliberately overworked by those who assigned the shifts.  While that specific decision was overturned in 2018 how far behind are you after five years and why would qualified people want to work for an agency with a documented history, proved by lawsuit, that you will discriminate against them?  Never mind the FAA's rather obvious and deliberate lie that they had met staffing goals just a few months ago.

Again safety-critical systems require at least two ****ups for a bad outcome to occur and this is intentional because people do **** up -- thus one ****up is never enough in a properly-designed safety system to get people killed.

The bottom line is that while it is clear the helo flew into the path of the aircraft and thus that is the actual cause of the collision what is also clear is that ATC had the corridor violation on their scope a full minute before the collision and a conflict alert 40 seconds before.  The presence of an aircraft outside of its known safe corridor is hard proof that the operator of that aircraft has lost situational awareness and that renders the risks unbounded.

There is exactly one correct course of action upon detection of that condition and incapacity to immediately rectify it: You order the aircraft on approach to go around and turn away from the conflict as that is the only reasonably-safe known path available since the helo pilot has conclusively demonstrated he or she does not know where they are.  Chew the helo pilot's ass afterward but you must immediately clear the conflict and thus restore the boundaries on risk by instructing the aircraft who's pilot knows where he is to do so.

That is always the correct decision -- this is not Monday-morning quarterback crap.  The person who has demonstrated lost situational awareness (irrespective of why) cannot be expected to accurately honor the command and since you have the other party at risk who has demonstrated to that point their competence and knowledge of where they are and a de-conflicting command can be given to them that will resolve the issue you issue the de-conflicting command to them.  There was plenty of time to do so from the point in time ATC was aware of a no-prior-notice excursion from the authorized flight corridor by the helo and that option was still effective even if you wait the additional 20 seconds (but IMHO you definitely should not) until the conflict alarm is formally posted by the ATC system.

We must demand that the root cause be publicly disclosed and remedied with criminal penalties for all involved who took deliberate actions leading to it, when the systems in place DID apparently give plenty of warning as designed and said system and its warnings was not executed against and thus the collision prevented.  Again it takes at least two ****-ups in safety-critical systems for a bad outcome to occur and we know the machinery, given that Rep. Massie has now validated the track data as true and not a fabrication, operated exactly as designed with plenty of margin and clear, unambiguous, no-clutter warning in plenty of time to prevent the collision and hard evidence visible to the controller that the helo was above the ceiling for its corridor and thus by definition operating unsafely, had thus unbounded the risk of flight in the area and was at risk of collision with another aircraft -- per the designed layout for that airspace.

We must not accept any sort of excuse-making for this event and its outcome.  If DEI crap is in any way responsible for this, and it certainly appears it was a factor AS THE FAA REFUSED TO HIRE QUALIFIED PEOPLE BASED ON THEIR RACE GOING BACK MORE THAN A DECADE every single ****ing person involved in that **** all the way up the line must HANG personally.

We learned nothing from either the Flint water disaster or the Ohio train wreck both of which had at their core the same issue: Competence was replaced by those who were not and safety-critical systems were not appropriately monitored by skilled, competent people working within reasonable boundaries of workload and when safety signals were raised they were not dealt with by defaulting to a known safe outcome.  The result was a bunch of poisoned people, including kids (with lead) in Flint, serious health and property impacts in Ohio and now an airplane/helo crash over the Potomac.

This is what happens when you "coast" on the things competent individuals, usually white men, built and maintained for decades without incident and then you believe you can apply other than merit as a criteria in employment both at hiring and retention within those positions.  Then to make up for the lack of competence you try to load the additional work on the remaining people which wildly exceeds (in this case by twice) reasonable levels and make excuses when an other-than-return to bounded risk decision is made immediately on detection of the out-of-bounds condition.  Its even worse when you get away with pulling that crap a few times first which is exactly what the Russians did at Chernobyl and we know what happened there.

People die when you do that **** and we must demand everyone responsible for those changes face personal accountability for it at a criminal level and every single one of those changes be reverted and those not up to snuff be fired right here, right now without regard to the race, sex or any other characteristic.

PERIOD.

To make it worse there are unverified reports that a pilot initiated a go-around the day before under similar circumstances so perhaps the incursion was gotten away with just one day earlier -- which just amplifies my point that its even worse when you do it and get away with it yet nobody slams you for doing it because that lead to the attitude that "oh it wasn't that serious."

The hell it wasn't!

And finally, before someone runs the old strawman argument yes, statistically-speaking commercial airline traffic is the safest form of travel (by far) on a per-mile-covered basis.  However, unlike a personal automobile where most of the time it is my skill and attention (or lack thereof) that is responsible for the outcome I am utterly reliant on the skill, sanity and competence of a thousand other people when I travel in an aircraft and thus anyone who abuses that statistic to claim that we can "afford" any other than merit-based hiring and employment anywhere in said system, or who implements same must be held criminally accountable for each and every death that results.