Transition Level
Right. here we go, climbing and descending in dense airspace and having to be constantly alert to the fact that there might be a missing level or two due to the pressure, which of course has to be passed time after time after time with all the possibilities of wrong readback or in a low pressure situation the need to stress mB's rather than inches.....and everybody else using hectosomethings. I hope beyond all hope that the CAA will file one of its more sensible differences, especially as the high ground found in Europe and the US etc. is not a UK feature. Trying to achieve vertical separation in a dense traffic area is difficult enough when everybody is on the same datum, I hope that representative trials are carried out on a UK airspace model before this goes any further. Try to imagine the transition across national and international boundaries, and even from one ATC sector to the next. Another factor that only an operational controller or pilot will appreciate is the huge increase in RT traffic on already congested frequencies....also the useful ATC tool for predicting vertical profiles in use at Swanwick will be that much less dependable.