Reagan National Airport Black Hawk-CRJ crash
Friends have been asking me about this evening’s crash between a U.S. military Black Hawk helicopter and a Canadair Regional Jet (CRJ) that was on final approach to DCA (Reagan National).
It’s a terrible tragedy, of course, and has led to speculation on X regarding terrorism. A review of the ATC recording shows that there was plenty of room for human error. Because the liveatc.net server is overwhelmed right now, I copied over the relevant recording of DCA Tower. Note that military aircraft communicate via UHF and, therefore, we will hear Tower talk to the Black Hawk, but not the Black Hawk talking to the Tower.
Below is the airport diagram. The Potomac River is to the right and above. Runway 33 begins at the center right of the drawing near the “Elev 10” (10′ above sea level) and “EMAS” (Engineered Materials Arresting System, designed to stop a plane overrunning opposite-direction Runway 15). The runway name of “33” indicates that an aircraft landing on it would be pointing roughly magnetic 330 (333 in this case) or northwest.
At 12:20 Bluestreak 5307, a CRJ-700, checks in and is cleared to land Runway 1 after rejecting an ATC-proposed change to 33 (“unable”). At 12:57 Bluestreak 5342, another CRJ-700, checks in and accepts a modified clearance to land Runway 33 (helps ATC get more departures out). At 13:50, the Tower says that winds are from 330 (northwest) at 15 knots, gusting 25 knots (will be bumpy in a helicopter).
At 15:05 there is some communication with PAT25 (the Black Hawk). At 15:50, Tower tells PAT25 about the CRJ’s lateral and vertical location and also where it is heading (“PAT25 traffic is south of the Woodrow Wilson Bridge a CRJ at 1200′ [landing?] Runway 33”). After an inaudible-to-us reply from the Black Hawk on UHF, the Tower says “visual separation approved” (this approval can be given in Class B airspace only if an aircraft says that it has positively identified another aircraft; we were given this approval every 5 minutes or so when operating our Robinson R44 helicopters in Boston Class B airspace for photo and sightseeing tours over the city; it was necessary because we were within a certain number of miles of the airliners even though we were never anywhere near the approach or departure paths of the jets).
At 17:25, DCA Tower asks PAT25 if they have the CRJ in sight. Presumably the Black Hawk pilots answer in the affirmative, having seen or continuing to see what they believe to be the CRJ that ATC is talking about, but we can’t hear this on a recording of the VHF traffic. DCA Tower then instructs the Black Hawk to pass behind the CRJ (might require a slight turn or slowdown).
At 17:47, we hear background conversation in the Tower (a reaction to the crash, perhaps).
At 18:10, American Airlines 3130 is told to go around. The recording for the next few minutes indicates some rough times inside the Tower.
It’s too early to say definitively what caused the crash, of course. However, it seems that there were multiple jets in the air and even multiple CRJs. It is easy to see airplanes, especially airlines, at night, but not necessarily easy to tell a CRJ from an ERJ or a CRJ from an Airbus A319. A two-pilot crew in a Black Hawk would almost surely be able to avoid a crash with an airliner had they seen it more than 1.5 minutes earlier, which they say they did. Thus, the most plausible explanation is that the Black Hawk crew and DCA Tower were talking about two different airliners (i.e., talking past each other).
So… there were some excellent humans with excellent training in the airliner, in the Tower, and in the Black Hawk. Everyone was operating in the most restrictive low-altitude airspace (Class B) that we have in the U.S. and under time-tested rules that have ensured safety despite congestion. At the same time, however, we have the limitations of a natural language (English) and the human brain, which may latch onto and commit to the first plausible airliner that it sees.
A few potentially complicating factors:
- Black Hawk pilots will fly with helmets, which reduce peripheral vision.
- Black Hawk pilots may use night vision goggles (NVGs), which make it easier to see dark stuff on the ground but harder to see brightly lit objects, such as a CRJ in landing configuration. NVGs dramatically reduce peripheral vision (Update: Pete Hegseth says that they were using NVGs)
- Military aircraft sometimes use modern standard ADS-B transponders that transmit x,y,z position, airspeed, and direction, but perhaps not always, and therefore the collision warnings provided by modern avionics might not be triggered
- Airliner Traffic Collision Avoidance System (TCAS) has some inhibitions below 1000′ and below 500′ so as not to distract pilots during landing, so even if the Black Hawk had its ADS-B transponder on the airliner’s avionics might have inhibited a collision warning
- Visual clutter from all of the city lights; it’s easier to pick out airports and aircraft at night in places where there aren’t brightly lit buildings, parking lots, and towers
For those who aren’t regular readers of this blog: I’m an FAA-certificated helicopter instructor as well as a former CRJ pilot for a Delta Airlines subsidiary. Landing and taking off at DCA were part of the Delta job. I also teach an aeronautical engineering class at MIT. I have never flown a Black Hawk, but I have trained experienced Army Black Hawk pilots to fly the Robinson R44. I have spent hundreds of hours in Class B airspace, the same kind of airspace that surrounds DCA, in helicopters while airliners were landing at Boston’s Logan Airport (it was very rare for us to need to cross the final approach course, for the jets, though; we typically avoided airliners by flying over the top of the airport at 1,500′ or above or by staying as low as 300′ above the ground when underneath the final approach course to an active runway).
What could have prevented the accident?
First, let’s reflect on the fact that last night’s situation was a common one for the past 60 years or so and there weren’t any previous accidents. So the interaction among river-following helicopters and landing/departing airliners wasn’t obviously unsafe. On the other hand, safety rested on human excellence and vigilance and none of us can be vigilant 24/7.
The easiest way to have prevented the accident would have been to eliminate the Army aviation unit involved in favor of Singapore-style congestion pricing for surface transport in the D.C. area. The aviation unit exists primarily to ferry around senior military personnel who don’t want to sit in traffic like the peasants must. As D.C. traffic has intensified over the decades and helicopters have become safer (twin engines; everything precision-machined; two pilots) more VIPs have decided that they’d rather get around by helicopter than by car. But let’s assume for this post that congestion pricing can’t happen and military brass won’t use Zoom and, therefore, what is essentially an air taxi operation is required.
Winston Churchill defined a fanatic as someone who won’t change his mind and won’t change the subject. That’s certainly me when it comes to the crying shame of modern software capabilities not making it into the cockpit or onto the workstations of air traffic controllers. Our desire for FAA-certified perfection makes it prohibitively expensive to put the kind of intelligence that we expect from a $500 drone into a $30 million airliner or $20 million Black Hawk. Imagine if the Black Hawk had an onboard assistant that could have said to the pilots “There’s an airliner at your 10 o’clock that you’ll hit if you don’t slow down to 50 knots.” That would, presumably, have redirected their attention away from whatever airliner they thought they were supposed to focus on and prevented the accident. All of the data necessary for such an assistant are available in any non-antique aircraft: position, velocity, track over the ground, position and velocity of other aircraft (broadcast via ADS-B, which is its own disappointment). The only thing that was missing on the Black Hawk was a $1,000 computer wired to the audio panel and a straightforward-to-write-but-ruinously-expensive-to-certify computer program. Similarly, ATC could have benefitted from a program that spoke “It doesn’t seem as though the Black Hawk is doing anything to avoid the CRJ, despite your instruction.” The controllers will, no doubt, share some blame for not noticing an alert on their screens, but these types of alerts are too common and insufficiently specific for humans to deal with reliably hour after hour day after day.
(Check out Beacon AI for an example of a company that is trying to deliver smarter in-flight software to deal with the fact that we demand ever higher levels of safety in a world where humans aren’t getting smarter or more vigilant. Beacon AI has some military contracts and things may move faster in that domain because the military is not bound by FAA certification rules.)
What about “Trump blames DEI for weakening FAA in aftermath of Reagan National plane crash” (The Hill)? Although the FAA has invested heavily in DEI, I don’t think that was the proximate cause of this accident. There will inevitably be a distribution of ability among air traffic controllers. DEI-based hiring will sadly increase the number of those with lower ability, just as in any other field of endeavor. On the other hand, there are only 37 Class B airports in the U.S. out of roughly 500 airports with control towers. Thus, these 7 percent most-critical airports are going to draw their tower controllers mostly from the top 7 percent of all tower controllers. A mediocre or low-performing controller can be parked at an out-of-the-way airport that has just a fraction of KDCA’s roughly 800 operations per day (Westover, Massachusetts is a civilian-military airport that has a control tower and only about 50 operations per day, for example). In 1996, the FAA was trying to bend its rules to favor women (report). In 1999, the FAA was working on bending the rules to favor “African-Americans” (report). See also “Obama-era FAA hiring rules place diversity ahead of airline safety” (Fox News, 2018) and this undated recruiting video. Perhaps it would be fair to blame the FAA’s focus on DEI as a factor in slowing the agency’s ability to adopt innovation simply because time and money spent on DEI can’t be spent on improving operations.
Some previous articles that I’ve written about the negative impact on safety of the financial and calendar obstacles to certification (perfection is the goal and it becomes the enemy of near-perfect solutions that would be huge safety improvements):
- Boeing 737 MAX crash and the rejection of ridiculous data
- Certification process for the 737 MAX silent gradual pusher system
- Kobe Bryant crash: NTSB says that it was all the pilot’s fault
The classic paper on our limits as humans: “Gorillas in our midst: sustained inattentional blindness for dynamic events” (1999). The video that was part of the experiment (see if you can spot the gorilla, which roughly 50 percent of the experiment subjects (super smart undergrads?) missed):
Next steps for the NTSB and FAA
A reporter asked me what happens next. My answer:
- I don’t think that there will be anything interesting to learn from the cockpit voice recorders and flight data recorders other than, perhaps, a precise altitude for the crash
- the NTSB and FAA will pull the tapes (maybe they’re still actual tapes) from DCA Tower so that they can can hear both the UHF (Black Hawk transmissions) and VFR communications
- they’ll look at whether the Black Hawk was cleared to fly a specific route and altitude over the river (see the DCA helicopter chart below, which would have restricted the Black Hawk to 200′ and below; the accident has been reported to
