9G
Regardless of the weather forecast UK requires any operator to arrive with additional 20 min holding fuel on top as it's considered as no delay in the UK
Playing devils advocate here as we are talking theory rather than practice;
It could be argued that if the weather conditions, aircraft sevicability & ground facilities permit the use of alternate fuel to extend the holding time you have your extra 20 minutes (alternate & contingency fuel) & then some. Discuss
