Maybe Thursday 2nd March would be a good idea?
Ray Hanna's Memorial Service is being held at mid-day at RAF St Clement Danes, a couple of minutes walk from the 'Old Bank of England' where previous London meets have been held.
There'll be lots of aviators (famous and the rest of us, Ppruners/non-ppruners) attending that, and I doubt if they'll disappear off as soon as the service is over. There are several good pubs and wine bars very near the church.
BTW, the Memorial Service is open to anyone.
Details here
Link