Unthinkable that this Army Blackhawk helicopter would cross a restricted area at night without their ADS-B turned on, especially when planes are on final approach. I doubt very much that the air traffic controller knew exactly where this Army Blackhawk helicopter was, since it was too low to be on their radar, and worse the Army Blackhawk helicopter didn’t have their ADS-B on. (Will explain further below what ADS-B is). It is extremely unlikely that the American Eagle regional jet is at fault here because they were cleared to land by ATC on Runway 33 at Reagan National Airport. The American Eagle regional jet was about 400 feet off the ground and 2,000 feet, give or take, from the threshold of Runway 33. No helicopter belongs in that area, full stop, when airplanes are on final approach. So the Army Blackhawk helicopter is at fault here, in my opinion. Reports are that the air traffic controller asked the helicopter pilot to pass in the back of the American Eagle regional jet and by the time the air traffic controller finished that sentence, the mid-air collision occurred. And to make things exponentially worse, the Army Blackhawk helicopter didn’t have their ADS-B (Automatic Dependent Surveillance-Broadcast) turned on which would have trigged a T-CAS (traffic collision avoidance system) alert in both aircraft’s cockpits and given a TA (traffic advisory) to both aircraft to avoid the collision. How a helicopter could fly so close to an airport runway in, of all places, Washington, DC at night without their ADS-B turned on is mind-boggling. Incredibly, T-CAS prevented a mid-air collision two weeks ago near Phoenix Sky Harbor Airport between a Delta Airlines jet carrying 245 passengers and a United Airlines jet carrying 123 passengers as both jets were on final approach to land at Phoenix Sky Harbor Airport. Both aircraft had ADS-B, which triggered a T-CAS alert in their respective cockpits and issued a TA, which saved the day. The FAA requires all passenger jets to have T-CAS. ADS-B is the reason why you can see and track airplanes on Flight Radar 24 around the world. The Phoenix near-miss between the Delta Airlines Jet and the United Airlines jet is attached below. Worth watching. youtu.be/OVQKjihlorc