ferris, we may have to disagree on this one. However I will take you up on one small point. You said
you would have a hard time proving that locking on headings is safer than a perfectly servicable modern a/c flying on it's own nav
. What I actually said was
The only sure way of proving you did everything to ensure separation is to lock both aircraft on headings,
(my italics). There is a difference. All I would have to prove in court is that I did what has been, until now, the accepted (and SRG approved) way of ensuring lateral separation. I would contend that if I could not prove this,
then I am in trouble.
Frequency congestion and CBs. If an aircraft has been told "route direct XYZ", the pilot does not know if this is for separation purposes or the ATCO is being nice today. He wishes to avoid a build-up ahead, the frequency is humming, he is, in his mind, on his own nav. He deviates from track and tells ATC when he can get a word in sideways. Ooops! On the other hand, if told to "fly heading XXX" it should suggest that it is for a reason, probably separation. Heading deviation without clearance is far less likely IMO.
Nav aid failure. Well I suppose it depends what airspace you are in and what traffic you get. Not everyone has super-duper modern aircraft with fancy glass cockpits and all the gizmos. The system has to cater for the poor sods at the bottom if the IFR food chain i.e. the lowest common denominator surely?
First language not English. We obviously have different experiences of this!
So, some disagreement but hey, that's life.