Media reports have suggested the Ministry of Defence (MOD) plans to reduce an order for new early warning radar aircraft.

The Wedgetail aircraft programme has already been criticised by MPs unhappy about the lack of a competition to replace the RAF’s existing Sentry aircraft – known as its “eye in the sky”.

Reports now claim the planned purchase of five replacement aircraft could be reduced to three to save money. The MOD has not confirmed this. But could this leave the UK with a capability gap?

This Insight looks at the Wedgetail programme and the role of surveillance aircraft in the RAF.

What are surveillance aircraft?

Surveillance aircraft carry out a broad range of tasks often referred to as ISTAR: intelligence, surveillance, targeting, acquisition and reconnaissance.

Each aircraft type performs different functions, whether that is the submarine-hunting expertise of maritime patrol aircraft or the electronic surveillance capabilities of Rivet Joint. Collectively, they provide early warning and track adversaries, and provide targeted information to combat aircraft, warships and land forces.

Wedgetail is an airborne early warning and control system, commonly known as AWACs (or AEW&C). Easily recognisable by the large radar mounted on top, they are designed to track multiple targets at sea or in the air over a considerable area for long periods of time.

The Integrated Review is due soon

The Government is expected to publish its Integrated Review of Security, Defence, Development and Foreign Policy in October or November, setting out its vision of the UK’s role over the next decade.

Previous versions, known as Strategic Defence and Security Reviews (SDSRs), have made significant equipment announcements. It’s not unusual for rumours of possible cuts to be leaked to the media in the run-up to a defence review.

What did the 2015 review say on ISTAR aircraft?

The 2015 SDSR pledged to “enhance and expand” the RAF’s intelligence, surveillance and reconnaissance capabilities.

This included:

  • new P-8A Poseidon maritime patrol aircraft (the first of nine entered service in 2019)
  • doubling the number of armed remotely piloted aircraft by replacing Reaper with Protector (this programme has since been delayed by two years to save money)
  • extending the life of Sentinel (which provides wide-area battlefield surveillance) to 2021
  • keeping Rivet Joint and Sentry in service until 2035.
  • additional Shadow aircraft for Special Forces.

Why Wedgetail? An early retirement for Sentry

In 2018 the MOD decided against keeping Sentry until 2035, saying upgrading the aircraft and radar would not offer best value for money. Instead, the MOD said it was taking forward discussions with Boeing for its E-7 Wedgetail aircraft.

The decision to not allow a competition for the contract was questioned by MPs and the Defence Select Committee at the time. Then Minister for Defence Procurement, Stuart Andrew said: “there was no other proven capability,” that could fulfil the RAF needs in the timescale available.

In March 2019 the MOD signed a £1.51bn contract with Boeing for five aircraft.

Media reports suggest a smaller fleet than planned

In September 2020 The Times’s defence correspondent, Lucy Fisher, reported on Twitter that the MOD is considering reducing the number of aircraft to be bought from five to three. Jane’s Defence Weekly magazine confirmed with an unnamed senior MOD source that the MOD is considering a reduction to save money.

In the Defence Equipment Plan 2019, the MOD forecast the costs of the Wedgetail programme to be £2.16 bn. When asked about the difference, the Minister for Defence Procurement explained the figure of £1.51 bn relates to the value of the aircraft procurement contract, whereas the £2.16 figure includes training and future support costs.

The National Audit Office has described the defence equipment plan as “unaffordable”.

Does a smaller fleet matter?

Douglas Barrie, a military aerospace expert, explains that given maintenance and training needs, a fleet of three could create gaps in coverage. This, he said, would be “sub-optimal” given increasing Russian air activity.

The National Audit Office said the MOD has already reduced the number of Sentry aircraft from six to three in 2020 to save money.

A possible ‘capability gap’ in 2023?

In this context, ‘a capability gap’ could occur if a needed, existing piece of equipment is retired without an immediate replacement.

Parliament has taken a keen interest in capability gaps in the armed forces. The Defence Committee examined the gap in maritime surveillance in a 2012 report.

The National Audit Office says the RAF has brought forward Sentry’s retirement date to December 2022, nine months before Wedgetail is expected to enter service. However, the Defence Equipment Plan 2019 says entry into service is December 2023, leaving a 12-month gap.

In addition Sentinel, another long-range surveillance aircraft, will be withdrawn in March 2021. The MOD has explicitly ruled out postponing its retirement date.

The MOD says there will be no capability gap if the Wedgetail order is reduced to three. The Minister for Defence Procurement, Jeremy Quin also said: “the transition from Sentry to E-7 Wedgetail will not result in any reduction in current capability.”

Further reading


About the author: Louisa Brooke-Holland is a researcher at the House of Commons Library, specialising in international affairs and defence.

Image: A Royal Australian Air Force E-7A Wedgetail – U.S. Air Force photo by Staff Sgt. Daniel Snider under Public domain (Cropped)