I guess it depends what runway you want to watch - for the southern runway, if you catch the choob to Hatton X, walk out to the left of the roundabout, past the Barclays Bank, turn left and walk into the carpark for the BA
technical area (it used to be outside the security cordon, not sure these days), you can get very close to the end of the southern runway eastern end - Concorde taking off used to set off car-alarms there, so its pretty close.
For the other runway, for the Eastern end, as well as to watch aircraft crossing the perimeter road between the TBA//J/K hangars and the main airport area, there's a roundabout about half a mile up the road from Hatton X which is a popular breeding ground for the Lesser-Spotting Anorak.
Young and beautiful and thin and gorgeous AND BANNED ! Cya at airspaceonline.com, losers