Originally Posted by
ignorantAndroid
I may be mistaken, but my understanding is that the controller doesn't really have the option to deny visual separation. The regulations don't mention any response except 'approved.' The word 'approved' does seem to imply that it could also be denied, ........
For a while I was flying schedules which were often conducted SVFR as they were
very short legs
. I'd often get from Twr on joining the circuit at my various destinations, and having confirmed I'd got traffic XYZ in sight, a clearance "Roger, C/S, keeping that traffic in sight, report Final XX. You are No 2 to the XYZ.". From that point on, my positioning was determined by me based on visual separation with the other traffic - so not totally identical to the DCA accident but the principle was the same - I was responsible for remaining clear of XYZ and positioning appropriately behind them (including accounting for wake/runway occupancy effects etc). Occasionally I'd then get "C/S, new clearance - report
ready for L/R base." usually with a reason if there was time - often it was App not leaving TWR a big enough gap to sneak me in between 2 IFR arrivals.
In other words, Twr would delegate separation to me with the initial clearance but, if for whatever reason, they became unhappy - I got issued with a revised, more restrictive, clearance. Similarly, if I lost sight of the traffic at any point after the initial "Report Final" clearance, it was my responsibility to advise ATC that I was no longer visual with XYZ (ie I could no longer comply with the clearance ATC had given me) and ATC would then update my clearance on that basis - "..... report ready for base" or similar until they could visually assure themselves of separation. Indeed, on those occasions, it was not unknown for ATC to say "C/S, I have you both in sight - that traffic is well ahead of you, report Final XX, No 2". I was thus relieved of my responsibility to self-position.
What ATC giveth away in their airspace ATC can taketh back again in their airspace!
Now, "normalised deviation" may skew such a way of working such as PAT routinely expecting to get what they ask for and ATC routinely giving them what they want......... Not saying that happened at DCA but............ Also, I've lost track in the Thread if PAT were visual but with another a/c or the intended one but simply "lost it" at some point........... And whether visual separation at night in such busy airspace was wise ............