London Heathrow airport is delaying the switch of runways due to ongoing technical issue.
Due to an ongoing technical issue in process of being resolved the main London Airport is delaying switching of runways.
The current configuration, landing 27R and departing 27L will remain until 18:00 local time.

The alternation pattern means that for part of the day the Airport uses one runway for landings and the other for take-offs, then halfway through the day at 15:00, it switches over.