What is "flight route 4"?

The FAA publishes supplemental charts specifically for helicopters in areas with high concentrations of helicopter activity: https://www.faa.gov/air_traffic/flight_info/aeronav/productc...

Specifically the Baltimore-Washington route chart was relevant for these flights: https://aeronav.faa.gov/visual/10-31-2024/PDFs/Balt-Wash_Hel...

If you find the DCA airport on that chart, you’ll find routes 1 and 4 which roughly correspond to the helicopter’s flight path.

This comment was written by a US Coast Guard helicopter pilot. It gives a lot of information on how the two aircraft should have been able to share the space and some speculation on what went wrong:

https://www.reddit.com/r/aviation/comments/1idba8i/comment/m...

That makes sense.

A helicopter instructor suggests that possibly the helicopter pilots, who were told to go behind an aircraft that was landing, were looking at the previous aircraft that was landing.[1] That's just speculation at this point.

[1] https://philip.greenspun.com/blog/2025/01/29/reagan-national...

They could use the car autopilot solution: simply negotiate your coordinates with nearby traffic instead of trying to parse malformed visual data.

They were almost certainly both cleared to maintain visual separation.

> They were almost certainly both cleared to maintain visual separation.

DCA TWR: PAT25, traffic just south of the Woodrow Bridge, a CRJ, it's 1200 feet setting up for runway 33.

PAT25: PAT25 has the traffic in sight, request visual separation.

DCA TWR: Visual separation approved.

Audio of MID-AIR CRASH into Potomac River: https://www.youtube.com/watch?v=CiOybe-NJHk