Vector Aerospace were formerly part of MOD and now maintain and service many of the UK's military helicopters. The tour will be of interest to those interested in aerospace, defence or engineering in general.
The tour will begin at 1000 and last for between two and three hours. Due to the nature of Vector's work the tour is only open to UK nationals.

http://www.vectoraerospace.com/vector_aerospace_-_locations/fleetlands_-_helicopters.aspx