It Had Been 16 Years Since a Fatal US Airlines Crash.

But there appears to have been another one this evening.

An ADSB-Exchange screen shot of flight paths that tragically intersected this evening, over the Potomac River in Washington DC. From the south, a regional jet flown by American Airlines approached Runway 33 at National Airport, DCA. From the north, an Army Blackhawk helicopter crossed its path.

I am writing from the opposite side of the country, thousands of miles from our normal home in DC and the locale of this evening’s apparently fatal aviation disaster above the Potomac, close to National Airport in DC.

There appears to have been a disastrous collision between a regional jet, a CRJ made by Bombardier and flown by American Eagle Airlines, with more than 60 people aboard en route from Wichita, and a military helicopter, reportedly a Blackhawk flown as “VIP Transport” by the US Army. News footage from local TV stations captured the collision, for instance this from local NBC news.

The news is terrible and still unfolding. As in all aviation disasters, early reports can be misleading; I’ll follow up with more details tomorrow, as more become known.

The most recent mass-fatality crash had been almost 16 years ago. That was in February, 2009, when the crew of a Colgan regional turboprop, a feeder for United Airlines, apparently mis-managed an icing emergency, and crashed on approach to Buffalo, New York.

Since then, the relentlessly safety-minded collaborative culture of the US air travel system has made commercial airline travel in the United States the safest mode of travel ever invented. Not counting today, a total of two people had died in US airline accidents (over more than 12 billion passenger journeys) in the preceding 15+ years.

Now that record is at its end.

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Three short points, as a prelude to more info as it becomes known.

• How and where did this happen? Planes on approach to DCA typically fly “up the river” or “down the river,” the river being the Potomac in both cases.
  When winds are from the north, inbound planes typically fly “up the river”—northbound along the Potomac, with the cityscape of Alexandria, Virginia visible from the left side of the plane, and first Anacostia and then the US Capitol and other DC features visible from windows on the right side.
  Otherwise inbound planes fly “down the river,” southbound above the Potomac, with Key Bridge, the skyscrapers of Rosslyn, Virginia, and then the Pentagon closely visible from the right side of the plane, and Georgetown University, the White House and Capitol, and other sites in downtown DC visible on the left.
  From news footage, it appears that this plane was flying up the river, toward a landing on Runway 33 at DCA. Somehow the Army Blackhawk helicopter flew at its altitude, directly across its inbound path.
  

• Why didn’t the aircraft know about each other? This will be the main focus of investigation. The airspace above very busy big-city airports is very tightly coordinated and regulated. The controllers who handle traffic in and around DCA, LAX, SFO, LGA, ORD, and similar first-tier airports have the skill of orchestra conductors in the four-dimensional ballet of imagining how flight paths will intersect. (Four dimensions? One of them is time: Where each of these planes is now, and where it will be twenty seconds from now.)
  
  The main clue available as I write is a tape of transmissions from the DCA tower around the time of the accident. If you listen carefully at around time 17:30 of the clip below, you’ll hear a DCA tower controller asking the helicopter (with call sign PAT two-five) “do you have the CRJ in sight?” The CRJ is the inbound commercial plane. We don’t hear the answer on this tape, presumably because it was on another frequency. But presumably the controller did hear the answer. (Among the skills of controllers is handling several frequencies at once.) He then says to the helicopter, “pass behind the CRJ.”¹

  
  After around time 18:00, you hear all hell breaking loose, after the crash has occurred and as the tower tells other airplanes to break off their approaches and go around.
  

  Who knew what, when? We’ll presumably learn more. In any case, a terrible tragedy.
  

• The culture of air safety. On his second day in office, as part of his careless-or-intentional destruction of the institutions that have made the United States strong and safe, Donald Trump disbanded a group called the Aviation Security Advisory Committee.
  
  As I had planned to write that day, this casually punitive gesture had the potential of undermining everything that had made US aviation safety the marvel of the world. It was collaborative; it combined public, private, military, civilian, academic, and other institutions to pool knowledge; it avoided blame; but it focused relentlessly on lessons learned. You can see a list of its members here.
  
  I didn’t write about it that day, because life got in the way in various forms. But if I had I would have said: Destroying this institution probably won’t make a difference this week. Or this month. Or maybe even this year. But in the long run, some day, it will be part of an erosion of safety —part of the thoughtless destruction of the taken-for-granted institutions that have made modern aviation as safe as it is.
  
  That dismantling order, one week ago, wasn’t part of tonight’s tragedy—whose specific origins no one knows, as I write. But unless reversed, it will be part of tragedies in the future.

More details to come tomorrow. In the meantime, condolences to all affected by this disaster.

1. For context: You hear instructions like this all the time when operating in “visual conditions” at a busy airport. The controller will ask to verify that you have “visual contact” with another airplane. Once you confirm that you can see the other plane, the controller will say, “pass behind,” “maintain visual separation,” or in other ways ensure a margin between one plane and another. To emphasize, this is a perfectly routine sort of instruction to expect and receive.
It’s different under “instrument conditions,” when the expectation is that none of the flight crews can see any others, and the controllers are responsible for keeping the planes safely separated, by several miles. For whatever reason, the separation instructions did not get across in this case.