Opinion.
It is a long while since I've been there, but that Manchester MANTIS noise set up in the opinion of this individual is a disgrace. The tracks to the south are related to a VOR sixty miles away. It is obviously not recieved on the ground, the aircraft climb into it. The tolerance on VOR tracking is 5.2 degrees, which translates to five miles at that distance. Plus or minus. The noise tracks are predicted on track tolerances generated using pure statisics. A few hundred metres. The pilots are REQUIRED to track on the VOR once the flag is gone and they have an ident. This naturally gives the MANTIS people unlimited oportunity to fine airlines and ruin careers without anybody having done anything wrong.
The CAA airways surveyors and the CAA flight inspectorate let them get away with it, presumably because they are not at risk and therefore don't care.
Pick 'em all up in a giant cargo net and drop them in the ocean, it will be alright with me.