Web track
Webtrak is a system devised and run by Heathrow Airport which shows the planes landing and taking off. It has a 24 hour delay but you can see the flight paths the aircraft use. Regard it, though, as a general guide rather as always showing a flight path with pinpoint accuracy.
Flightradar24.com
Flighttrader is really an air enthusiasts’ site covering the world but you can home in on any area you wish to see. It is live.