A British Airways Airbus A319-100, registration G-EUPB performing flight BA-747 from Stavanger (Norway) to London Heathrow,EN (UK), was descending towards London when fumes were noticed in cockpit and cabin, the crew received an indication "VENT BLOWER FAULT". The crew continued for a safe landing on Heathrow's runway 27L. The AAIB rated the occurrence an incident and opened an investigation.