UK Sentry fleet halved in less than 12 months

The RAF is withdrawing their E-3D Sentry aircraft

The Royal Air Force (RAF) has halved its number of operational Boeing E-3D Sentry AEW1 airborne early warning and control (AEW&C) aircraft, in preparation for its replacement, the E-7A Wedgetail.

In a Freedom of Information (FOI) response to a request from Key.Aero, the Ministry of Defence (MOD) confirmed that since the announcement of the UK’s procurement of the Boeing E-7A Wedgetail in March 2019, the RAF’s fleet of E-3D Sentry AEW1 aircraft has been reduced from six to three.

In January, E-3D Sentry AEW1 serial ZH104 (c/n 24112/1007) was withdrawn from operational service and placed in storage in the US. This followed the withdrawal of both ZH102 (c/n 24110/996) and ZH107 (c/n 24499/1012) in March last year. These aircraft have been placed in long-term storage at RAF Waddington, Lincolnshire, awaiting disposal, but they remain on the military register as of February 2020.

E-3D Sentry AEW1 [MoD Crown Copyright] #1
Boeing E-3D Sentry AEW1 - registration ZH106 (c/n 24114/1011) - flying in support of Exercise Taurus Mountain 3 over North Yorkshire in March 2012. MoD Crown Copyright

Before ZH104’s withdrawal, the Sentry fleet comprised four aircraft, with three operating in the forward fleet and one in sustainment. The remaining examples – ZH101 (c/n 24109/993), ZH103 (c/n 24111/1004) and ZH106 (c/n 24114/1011) – continue to routinely conduct NATO missions as part of the UK’s commitment to the alliance’s intelligence, surveillance and reconnaissance (ISR) operations.

In a response to a request for information under the Freedom of Information Act 2000 (FOIA), the MOD said: “The RAF’s fleet of Sentry aircraft have contributed to every major UK air operation since its introduction to service with the RAF in 1991. However, they are now ageing and as is eventually the case with all military aircraft, the decision was taken to replace them with a more modern and capable aircraft to meet the UK’s future needs.”

“The out of service date for [the] Sentry is being kept under review as the transition plans are refined”, it added.

Boeing E-3D Sentry AEW1 [Khalem Chapman]
Boeing E-3D Sentry AEW1 - registration ZH101 (c/n 24109/993) - preparing to depart RAF Fairford after being on display at the Royal International Air Tattoo 2015. Khalem Chapman

At its height, the RAF operated a total of seven E-3Ds under No 8 Squadron and No 54 Squadron from their home base at RAF Waddington. In UK Financial Years 2017/18 and 2018/19, the fleet flew some 820 and 780 flying hours respectively. In 2009, the RAF withdrew ZH105 (c/n 24113/1010) and this was used as a source for spares for its operational counterparts. As of 2020, the aircraft still resides at RAF Waddington.

Modification work by Boeing on the first E-7A Wedgetail airframe – which is based on the company’s 737-700ER airliner – is scheduled to begin in 2021, with the first aircraft for the RAF due for delivery in 2023. Additional work on all five of the aircraft ordered will be conducted by Marshall Aerospace and Defence Group at its facility at Cambridge City Airport in Cambridgeshire.

Find more military aircraft news in our military aviation & airforce news section.