Dr Julian Lewis: To ask the Secretary of State for Defence, in which (a) conventional and (b) counterinsurgency campaigns Sentinel aircraft have seen action since their entry into service; what the original design life of each Sentinel aircraft is, and by how much this can practicably be increased by a life extension project; whether the UK possesses alternative systems that can provide (i) strategic and (ii) tactical surveillance coverage over land equivalent to that currently provided by Sentinel; and how future land campaigns will adequately be conducted if a capability gap is created by the retirement of the Sentinel fleet. 
[Due for Answer on 20 May. Answered on 21 May.]
HOLDING ANSWER: The Ministry of Defence has indicated that it will not be possible to answer this question within the usual time period. An answer is being prepared and will be provided as soon as it is available.
The Minister of State for Defence Procurement (Jeremy Quin): The Sentinel R1 has been operationally deployed in support of a number of operations. Some operations are considered to be both conventional and counter-insurgency; for example operations in Afghanistan (Op HERRICK) and Iraq (Op SHADER). It has also been deployed on operations in Libya (Op ELLAMY), Nigeria (Op TURUS) and Mali (Op NEWCOMBE), all considered conventional operations.
Sentinel was introduced in 2008 in the knowledge that a significant equipment upgrade would be required in the mid 2010’s.
The Defence Review in 2010 cancelled this expected upgrade bringing forward the likely out of service date.
The SDSR 2015 determined that Sentinel should be retained for a further period and set a new out of service date of March 2021. While some work was conducted on the on-board equipment this fell well short of a full system upgrade.
The radar and mission system are now increasingly obsolescent and will face increasing reliability issues as time progresses.
Retaining the capability would have required significant upgrade expenditure and the March 2021 out of service date has been retained.
No identical capability is operated by the UK (though similar capabilities exist in the NATO inventory).
The UK does however have a number of other intelligence, surveillance and reconnaissance capabilities that collect different types of intelligence information, including long-range strategic assets (Sentry, Rivet Joint and Poseidon) and shorter-range more tactically-focused assets (including Shadow, Reaper and Watchkeeper).