Originally Posted by
Evalu8ter
The arguments about fuselage plugs and different undercarriage are all well made but fail to appreciate that the Pu2 project was not about capability enhancement, it was about life extension and that was the sole basis for funding.
Exactly what Evalu8ter said. Part of the initial brief was "don't ask for a new helicopter, there isn't any money ". The published cost of the Puma programme included (AIUI) a fair amount of through-life cost as well, so cannot be directly compared to the simple upfront cost of a new replacement.
Leasing 532/725's was eye-wateringly expensive, even before you got to the questions of what happens if you get bullet holes in them (we had 2 shooting wars going on at the time) or need urgent operational mods in less than the 20 years it would take the manufacturer/owners to approve them.
The choice was between refurbed Sea King Mk6s or life-extended Pumas. The Puma option was chosen, the rest is as Evalu8tor has most clearly explained above.