Two years ago, Britain decided to have eight Chinook Mk3 (MH-47) helicopters converted from their special operations role, to standard combat transport models (CH-47), at a cost of about $15 million each. The eight Mk3s originally cost over half a billion dollars (all together) and entered service (or, rather, inventory), nine years ago. But they have rarely been used, and the need for transport helicopters in Afghanistan is acute. Britain has 40 Chinook transports, and this conversion will make it 48. The Chinook can carry up to ten tons of cargo, or up to 55 troops. A new Chinook would cost about $40 million.
It may be another year before the Mk3s are successfully downgraded from commando carriers, to just transport helicopters. The problem was caused by British Defence Ministry officials screwing up the acquisition of the avionics software for the commando version. The ministry officials were never able to rectify that, but they have apologized.