General Discussion

LAST EDIT: Another FAQ, then I have to sleep.... What about TCAS? - TCAS is great but speaking for the systems I'm familiar with, they're not primarily designed for a dense airport environment like that... its accuracy at short range is not great, and with so many aircraft so close to you, including those that are sitting on the ground at DCA, you generally have to mute or inhibit the alerts because it would go off constantly and drown out your communications with your crew and ATC. Think about a ring doorbell camera: it's great for alerting you when a suspicious person shows up unexpected at 1 AM, but it's not much good while you're having a house party at 7pm... you probably muted it because you KNOW there are dozens of people there and you're okay with it. I have no idea what kind of system the CRJ or H60 have or what their procedures are, but it's possible that TCAS could have been saturated/muted while flying that close to DCA, and even if it wasn't, they may not have been
able to distinguish the alert for the CRJ from another aircraft until too late.