Holding answer received on 23 October 2014
With regards to the signature of contracts for the life extension of the Sentinel aircraft fleet, I refer the hon. Member to the answer I gave on 1 September 2014 (Official Report, column 103W). To date, no related costs have been incurred. On current plans, a contract for the development and installation of the maritime capable software upgrade will be let in spring 2015. Sentinel was already fitted with a Dual Mode Radar when it entered service with the Royal Air Force.