To comply with the EU WTD one needs 4 crews for 24/7 coverage, therefore one needs 8 crews to have permanent 2nd helio coverage. Or did you mean we cant afford it
Your Maths isn't very good Shipmate..... If you need 4 crews to man 1 aircraft then you need 5 cxrews to man 2 aircraft.
If an RAF crew is a crew of 4 (2 Pilots, Crewman and winch Op) then by your reckoning you would need 32 people to man 2 aircraft? If 1 aircraft is the Duty and the other is the Standby that means you would have 4 people on Watch and 28 people Off watch...? That would never pass the Daily Mirror test.
I may be mistake but I think that Gannet SAR flight (The UK's busiest SAR Flight) have 2 Aircraft and 4 crews....sometimes 3 1/2 crews.