Comment by ibejoeb

This is pretty much right, by the book. It seems clear that there were multiple confounding factors: a high risk, under-resourced training mission performed by relatively inexperience pilots operating as a normal transport mission as far as the controllers were aware.

I think we're going to wind up talking about SOP and whether visual separation is permissible in this class of airspace when using NVGs or under other conditions present in this mishap, e.g., on nighttime training. There are companies (lufty for instance) that, by policy, prohibit visual separation at night.

There might be some scrutiny on the controller for approving visual separation in the first place, and I think that'll get into weeds of how he should have known the risk factors for the helo. Still, as Juan notes, it didn't sound like thoughtful consideration, but like rote call and response.

This would have been prevented if the helo had to take vectors. There would be no talk of visual separation. The controller was aware of how tight it was, and if it were simply a rule, he would have told the helo to hold present position, waited for an appropriate place in the sequencing, and then given a clearance.