Just a heads up reminder that the security workers in LHR T5 have a strike action scheduled 31 March - 9 April. There is a live thread currently on FlyerTalk about conditions as well as the recommendations from British Airways about how to navigate. The strike began today and the posts so far seem to indicate not too much disruption, although there have been British Airways flight cancellations.
Edit: I fixed the previous title to more accurately describe the situation (note to self about trying to post early/late in the day).