Originally Posted by
Herb687
Do you know if military would transmit to KDCA tower on UHF
I'm pretty sure the helicopters would have VHF. It's generally only fighters that only have UHF radios.
Originally Posted by
AMflier
Report in Washington Post that some are also being diverted to BWI
They divert to whichever airport the Captain decides to divert to. ATC only tells them were they can't go, not where to go.
Originally Posted by
Duke787
How in the world did TCAS not prevent this?
The CRJ had TCAS as it's required. I have no idea about the helicopter but the helicopter would have a Mode-C (or S) transponder and that's all the CRJ's TCAS needs to detect it. Transponders are required, and required to be on, in that airspace.
Unfortunately, the collision appears to have occurred at an altitude at which TCAS can't help. Resolution Advisories are inhibited below 1,000' as, below that, it isn't safe for it to command altitude changes which could conflict with terrain. The Traffic Advisory would still be displayed but aural warnings are inhibited below 500'. Inhibited (silent) TAs are displayed with some regularity when that close to the ground due to the close proximity of all the other airport traffic. We see then on the display for situational awareness.
Initial ATC audio suggests that the helicopter had reported the CRJ in sight and had been instructed to pass behind them and to maintain visual separation. That type of separation is used routinely with helicopters in the vicinity of airports.