Most aircraft arriving into Manchester Airport use the Instrument Landing System, which in line with most other airports has a glide slope of 3 degrees equal to descending 318 feet per nautical mile.  The prevailing wind direction is westerly, so normally aircraft fly from northeast to southwest. In practice this means that normally aircraft land from the northeast over Stockport, Cheadle and Heald Green and takeoff towards Knutsford. In dual runway operations aircraft will usually land on to Runway 1 (23R) and depart from Runway 2 (23L). When the wind direction changes, usually affecting 20% of movements per annum, operations are reversed with aircraft landing from the southwest, lining up to the south over Northwich and over Knutsford and taking off towards Stockport.  In dual runway operations aircraft will usually land on to Runway 2 (05R) and depart from Runway 1 (05L).  Sometimes, aircraft arriving into Manchester Airport are held in stacks, usually in poor weather when the movement rate decreases.  The airport has 3 stacks: DAYNE, MIRSI and ROSUN, each located approximately 15/20 miles from the airport.  DAYNE serves arrivals from the south, ROSUN from the north and east and MIRSI from the west.  If you live within 20 miles of the airport, you will likely see and hear aircraft.