[matheweis]

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.

[Animats]

Right.

Helicopter was on Helicopter Route 4, per the map, apparently on course.

Aircraft was on approach to Runway 33, apparently on course.

That helicopter route crosses the approach to runway 33.

That's controlled airspace. How did they both have clearance to be there?

We'll know more tomorrow as all the audio and radar recordings are examined.

[hluska]

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...

[agsnu]

They were almost certainly both cleared to maintain visual separation.