Not quite Altrincham, but I live in Marple. I'm always struggling to find time for flying, so I mostly end up flying at Lyme Park. Not the best flying site, but being NT run, it's completely chav free.
Stuart B's probably the closest experienced flyer to you and I believe he flies at Hough End Playing Fields, but he's a bit like me and sneaks out to fly when he can.
One of the issues flying in Manchester is the almost total lack of good flying sites, so most of us will be seen heading further afield when we get a chance.
If you've got transport, probably your best bet if you are a dual line flier is to jump in a car and head towards the Dips at New Brighton on the Wirral or towards Otterspool Promenade in Liverpool, where most of the NW fliers tend to congregate.
There's more trick flyers at the Dips, but I've no idea whether they have a regular flying time, whereas the group at Otty will be there practically every Sunday.
There's also a group of (mostly Rev) flyers who fly at Ainsdale Beach most Saturdays, which has to be one of the best flying locations in the North West and is also worth a try.
HTH