Unfortunately it always seems the Treasury puts the boot in and can only be persuaded to fund an 'upgrade' - ie Shackleton Mk 2 to Mk 3, Nimrod 2 to 4, Sea King (too various to mention)and the same with many other items across the military spectrum. So we end up with cost overruns, old equipment with (relatively) modern upgrades etc, instead of new build, more efficient and in the long run cheaper aircraft etc. And who gets the blame - MoD or the single service involved.