27/09.......in the UK flights operating on an IFR flight plan only get protection in Controlled Airspace, out side Controlled Airspace they get no protection at all unless they are recieving some form of radar service from an ATC radar unit, in this case they will be offered either a traffic service or deconfliction service. Basically they will be advised of any known or observed traffic by the controller and the flight will either take his own avoiding action under a Traffic service or will be given avoiding action if recieving a deconfliction service.
Many commercial flights in the UK operate IFR outside controlled airspace because the airfield they are flying to has no controlled airspace to either protect it or an area en route to it. For instance Ryanair traffic inbound to Londonderry Northern Ireland will fly along controlled airspace as far as it can but at some time will have to leave for the final 30 miles or so to the airfield. They will still be recieving a radar service from Scottish control but traffic information will be only given to the pilot on traffic the contoller either knows about or can see on his radar.
Also dont get mixed up with IFR and IMC, an aircraft operating on an IFR flight plan may indeed be operating in VMC throughout its flight.
By the way, my ex ATC boss Is now running your ATC area control centre but it looks like she is having a tough time!!
http://www.3news.co.nz/nznews/video-...#axzz3hPF4lDp4