BOI into the 2012 Tornado Collision over the Moray Firth

[Distant Voice]

Easy Street, what I said was;

I understand that RAs will only be generated for aircraft above 1000ft. Neither of the "Moray Firth" aircraft would have received one, had they been fitted with TCAS

What I did not say

TCAS would have been of no use in the Moray accident]

What the SI reports says (1.4.4.129);

ASTON 1 and ABBOT 2 would have been given a TA, 23 secs before impact and an audio warning. Neither oral nor visual alerts would have been generated, since both aircraft were below 1000 ft AGL (where the generation and announcement of RAs is suppressed by TCAS II logic).

DV is trying to show that even with TCAS on the way, the Tornado collision risk is not ALARP.

Correct. Because we are fitting a piece of civilian kit that was rejected back in 1991 due to its unsuitability for the FJ environment. This is supported by the SI report (1.4.4.109)

ACAS II has been designed for civil aircraft and the surveillance requirements are based on typical performance envelopes of such aircraft.........UK FJs routinely manoeuvre outside the design parameters

Furthermore, the Risk Register indicates that no risk reduction can be anticipated once TCAS II is fitted. A point that may have been lost on some people, but not Dervish. He sees the relevance of such a statement.

Onceapilot

Not sure I understand your point DV? I expect most people would support a working bespoke FJ system, but why slag off TCAS? Basic TCAS would have provided traffic awareness. Surely your point should be that they were not even provided with TCAS, let alone a FJ optimised version.

You are correct, basic TCAS would have provided traffic awareness, and the SI report makes that quite clear. I am not slagging it off. The point I was trying to get across is that having identified the limitations of TCAS back in1991 a bespoke FJ collision warning system was successfully developed and flight tested. It was designed to operate at low level. Of course the RAIDS collision warning option could have been provided back in 2002, once someone decided not to go ahead with the bespoke system.

DV