Can someone advise me why I cannot replicate the EGLL - VHHX 'SID' as used by Don Grainge in the Cathay Pacific DVD?'Brookmans Park 2 Juliet' SID is used but dosen't appear to be available any more?

Could be possible, I have just checked the charts for BPK Sid's (dated 10/05/07) and BPK2J is no longer available. Never mind, the SID still exist but with another letter => now we have BPK6F - BPK6G - BPK5J - BPK4K depending on what Rwy you take off.I don't know when this video is created but it must be a while ago, so the numbers of the SID for Brookmans Park (BPK) has probably also changed.Maybe a specialist can give more details about when the numbers are changing ...

The number will change everytime the SID is updated (usually for new altitude restrictions or VOR radial updates). Consequently, BPK2J is now the BPK5J off 09R. The SID route will probably be essentially the same, but there have been 3 updates of the SID since the video.

Thanks both for a very understandable explanations.