The Mk3 Chinooks, when they come into service will be a big enhacement in capability but wait till it happens, the older Chinooks will end up being mothballed and so we will be back to square one again...
Did you pluck this out of mid-air or have you some hard facts to back this up?
The re-engineered Mk3 Chinooks are still set to be issued to the sqn they were originally destined for with the Chinooks that will be displaced being re-introduced to 18/27 pool so that the operational workload can be spread across a larger fleet. There are no plans to mothball any Chinooks, at least there wasn't last time Harry Staish at Odious had a chat with us.
I believe (although someone with a more engineering based background may be able to confirm or deny this) that the limiting factor on the Chinook fleet isn't the age of the actual airframes but the availability of parts, which as the Chinook lines are still open shouldn't
technically be an issue.