First and last comment.
"At 1122:44 the controller provided the pilots in JQF with the following traffic information:
"6 [nautical] miles in your 12 o’clock is alpha echo mike, a King Air. They are inbound to Mangalore for airwork. Passing 5,000 [ft] on descent to not above 4,000 [ft]"
"At 1122:49, five seconds after the controller passed this traffic information to the pilots of JQF, an aural and visual short-term conflict alert (STCA)[6] was provided to the controller."
"By this time, JQF was climbing through 3,250 ft, had a ground speed of 81 kt and had commenced a turn to intercept their planned outbound track from Mangalore Airport to LACEY (Figure 2). At the same time AEM had a ground speed of 187 kt and was descending through 4,918 ft on a track of 354⁰. At this point, there was 5.4 NM horizontally and about 1,675 ft vertically between the aircraft."
First thoughts: from a practical POV.
Head to head - six miles separation.
One climbing, one descending.
Closing speed = 81 + 187 :: 268 Knots. (496 Kph). = 4.46 a minute. = 1.34 minutes to meeting.
Climb and descent rates (estimated) say a mean of 500 fpm each (call it a combined 1000 fpm). AEM descending through 4918' - JQF climbing through 3250'. that's 1668' vertical separation/1000 fpm = 1.6 minutes . Ballpark..
Lets call it 90 seconds to 'the conflict' zone. Options still wide open.
To quote the 'time warp' song "and then a step to the right" - a'la TCAS, a mere 15 second right turn each would have provided enough wriggle room.
Was there time to arrange a 'you maintain 4000 - we hold at 3500 until clear? Probably; but not the optimum - busy frequency - etc, etc.
Could the ATCO have stepped in and ordered an altitude hold - in time - legally? This I cannot answer. But it brings back the ghosts from the Benalla fatal. Personally, I'd like the ATCO to have that latitude; in a 'critical' situation, even as an advisory - but the ASA people concerned will have a much better idea of what is best practice than I have. Perhaps it is a question which someone who understands the system can answer.
Self separation - see and be seen - in anything other than the perfect situation is a loaded gun, with the safety off, once clear of the circuit, particularly when operating to IFR tolerances under training. Given the conditions and circumstances, at the time, could either aircraft have spotted the other? It is a reasonable question. Perhaps being the right answer; there was only a heartbeat or two between having a story to tell over an Ale and a tragic loss.
Who's to bless and who's to blame don't enter this argument; bur IMO, we need to come up with a resolution to the obvious 'hole' in that famous cheese to ensure that this event is never repeated - ever.
My two Bob's worth; going to sit with TOM and stay right out of it.
Toot - toot.
"At 1122:44 the controller provided the pilots in JQF with the following traffic information:
"6 [nautical] miles in your 12 o’clock is alpha echo mike, a King Air. They are inbound to Mangalore for airwork. Passing 5,000 [ft] on descent to not above 4,000 [ft]"
"At 1122:49, five seconds after the controller passed this traffic information to the pilots of JQF, an aural and visual short-term conflict alert (STCA)[6] was provided to the controller."
"By this time, JQF was climbing through 3,250 ft, had a ground speed of 81 kt and had commenced a turn to intercept their planned outbound track from Mangalore Airport to LACEY (Figure 2). At the same time AEM had a ground speed of 187 kt and was descending through 4,918 ft on a track of 354⁰. At this point, there was 5.4 NM horizontally and about 1,675 ft vertically between the aircraft."
First thoughts: from a practical POV.
Head to head - six miles separation.
One climbing, one descending.
Closing speed = 81 + 187 :: 268 Knots. (496 Kph). = 4.46 a minute. = 1.34 minutes to meeting.
Climb and descent rates (estimated) say a mean of 500 fpm each (call it a combined 1000 fpm). AEM descending through 4918' - JQF climbing through 3250'. that's 1668' vertical separation/1000 fpm = 1.6 minutes . Ballpark..
Lets call it 90 seconds to 'the conflict' zone. Options still wide open.
To quote the 'time warp' song "and then a step to the right" - a'la TCAS, a mere 15 second right turn each would have provided enough wriggle room.
Was there time to arrange a 'you maintain 4000 - we hold at 3500 until clear? Probably; but not the optimum - busy frequency - etc, etc.
Could the ATCO have stepped in and ordered an altitude hold - in time - legally? This I cannot answer. But it brings back the ghosts from the Benalla fatal. Personally, I'd like the ATCO to have that latitude; in a 'critical' situation, even as an advisory - but the ASA people concerned will have a much better idea of what is best practice than I have. Perhaps it is a question which someone who understands the system can answer.
Self separation - see and be seen - in anything other than the perfect situation is a loaded gun, with the safety off, once clear of the circuit, particularly when operating to IFR tolerances under training. Given the conditions and circumstances, at the time, could either aircraft have spotted the other? It is a reasonable question. Perhaps being the right answer; there was only a heartbeat or two between having a story to tell over an Ale and a tragic loss.
Who's to bless and who's to blame don't enter this argument; bur IMO, we need to come up with a resolution to the obvious 'hole' in that famous cheese to ensure that this event is never repeated - ever.
My two Bob's worth; going to sit with TOM and stay right out of it.
Toot - toot.