A technical point chaps. (ATC here)
If LCY is landing Easterly and LL is landing Westerly the approaches are NOT separated! Be ready for the base leg turn because if you miss it you will end up under the ILS for 27L/R at about 10 miles out, at 2.0A . At that point Heathrow are dropping to 2.5A. There has already been an airmiss and several occasions of compromised separation!