5miles, certainly, it was at MACC.
We had a long-running ATC hill-walking group there and we were occasionally joined by aircrew. It was a B757 training-captain who was out with with us one day, who told us that the a/c had the facility to do this and was curious as to why it was never used?
None of us knew about it, but at the time, we had a couple of 10nm wide airways which had traffic-orientation-schemes using radar headings where it might have been useful. No procedures were ever written for it's use and I don't think there was any RTF phraseology for it anyway.
I can't remember offhand whether it was written in a TOI, SI, or in the main body of the Pt.2. but I'm 90% certain it was there. Our last few Pt.2s were on CD, and all though I still have them, I can't remember the access-codes, so I can't give you a reference unfortunately.
Last edited by ZOOKER; 27th Aug 2015 at 10:49.