Just been back from a WSOp Fam visit in Cranwell, where the PTI's and NCAITC boss said that you should be aiming to clear the 2.4km in around 10mins 30s.
They also mentioned the Aircrew swimming test: 100m in Flying Suit ( any side or front stroke) and tread water for 2mins then climb out unassisted. I assume if you can run the 2.4km in around 10 mins, the Bleep test at OASC will be no bother ( I hope so anyway!)
WW1