Sea Kings are not uncommon coming into the area and are normally (in my experience) bringing in casualties off the Welsh mountains direct to either the Manchester Royal Infirmary or Withington Hospitals "burns unit". Mostly it is the Royal though and they generally land in Platt Fields Park, Rusholme.
If that was the case why they would be hovering over Altrincham stumps me. From Wales they generally track in along the M62 visually and turn in towards the parks general area when they reach the end of the M602. This was the description of the route I had from the last pilot to land there that I dealt with who had come in from Bangor Hospital having initially come from EGOV.
Quite a sight seeing a Sea King come down in the park in the wee small hours I can tell you
