CCBoy,
If you log into your candidate page on the britishairwaysjobs.com site, then click on the interview time, it will take you to a page that gives you directions to Cranebank and The Rivers. If you're getting the bus to LHR, then you can get on one of the FREE buses to Hatton Cross, 285, 555, 556 and 557. (These buses run within the Heathrow Airport Free Flow Fare Zone). Once at Hatton Cross, it's just a case of getting on the BA4 Staff Shuttle bus that runs about every 10 minutes. Hope his helps.