The P-8 Poseidon for the UK

The British government has confirmed that it is ordering nine Boeing P-8 Poseidon maritime patrol aircraft to fill the gap in UK capabilities left by the retirement of the Nimrod MR2 and cancellation of the follow-on Nimrod MRA4 in 2010.

The deal, which includes a £100-million Boeing maintenance, training and logistics facility in Moray in the northeast of Scotland to support the P-8s in service, will sustain around 2,000 jobs in the UK and cost £3 billion over their first ten years in service. The current plan is for the first two British P-8s to arrive at RAF Lossiemouth in Scotland in 2019, with three more to follow in 2020 and the final four in 2021. However, this schedule may slip by six months to a year, depending on how fast the infrastructure can be built to handle the new US-standard aircraft at Lossiemouth; original planning assumptions for a 2019 in-service date had anticipated an earlier commitment by the government than July 2016. 

There are many in the UK who would have been more comfortable with an open selection competition process for the maritime patrol aircraft (MPA), and who assert that even if the ambitious 2019 in-service date was a deciding factor – thereby giving Boeing a decisive advantage – a competition process could still have been accommodated. Still, since the P-8 has now been purchased, the much more interesting question is what does this mean for UK defence capabilities?

The MPAs’ role has long been of paramount importance for the UK’s defence and security. The UK’s geographic situation as an island nation leaves it dependent on sea lines of communication for both trade, resupply and power projection. Furthermore, because of the requirement for Russian submarines to transit the so-called ‘GI–UK gap’, an area in the northern Atlantic Ocean on both sides of Iceland which forms a natural choke point, the UK’s anti-submarine capabilities have traditionally been a core part of NATO’s collective defence mechanism. In addition, the fact that the UK’s sole nuclear missile system is submarine-based means that the greatest threat to its strategic deterrent is from Russian submarines, and that the most effective method of locating and co-ordinating attacks on those submarines is an MPA capability. The Royal Navy does not have sufficient anti-submarine forces in the surface or attack submarine fleet to adequately ensure the safety of its Vanguard-class ballistic missile submarines (SSBNs) and Queen Elizabeth-class carriers, whilst also maintaining assets on stations near the Falkland Islands, in the Gulf and in the Far East, as required by the government’s current wider global commitments. Furthermore, without MPA support to quickly search a wide area of water with sonobuoy patterns and guide other forces onto suspected ‘contacts’, surface warships and even nuclear attack submarines like the Royal Navy’s Astute class can find it very difficult to reliably find, shadow and maintain contact with modern rival submarines in large ocean expanses. 

Since 2010, whenever Russian submarines have been detected off the UK’s shores – particularly when an SSBN is due to go on patrol from Faslane – the UK has had to rely on assistance from allies for MPA support to ‘de-louse’ the missile boats before they can safely depart for their assigned deterrent patrol areas. The P-8 is likely to be extremely effective in this role once it enters RAF service, especially since the ‘seed-corn’ programme has allowed the RAF to sustain some of the invaluable experience that would otherwise have been lost from the disbanded Nimrod force by embedding experienced and new MPA crews in the fleets of the US, Australia, Canada and New Zealand. The fact that RAF seed-corn crews flying US Navy P-8s have won various awards in international anti-submarine warfare (ASW) competitions, such as the Fleet Challenge 2014, not only shows that past experience with Nimrod stands RAF crews in good stead on the P-8’s mission systems, but also that the RAF itself should be able to start operating its own P-8s with high efficiency almost as soon as the aircraft arrive at RAF Lossiemouth. 

The P-8 itself shares many mission system similarities with the cancelled British Nimrod MRA4 and indeed some of the Nimrod family sensors and systems were previously bought by Boeing and influenced the design of the P-8. The shared design heritage should not obscure the fact, however, that the US Navy’s core operating philosophy for the P-8 differs significantly from previous UK practice. In order to deal with the significantly larger areas of ocean that the US Navy required the P-8 to cover compared to UK requirements, the P-8 has been designed to interoperate with the Northrop Grumman’s MQ-4C Triton – a maritime wide-area surveillance version of the highly successful MQ-4 Global Hawk UAV. The MQ-4C Triton, being expensive, extremely high flying and unmanned, is unlikely to be procured for operations alongside the UK’s P-8 fleet in the crowded airspace around the UK. Indeed, the P-8 is more heavily optimised for wide-area surveillance at the expense of ‘low and slow’ ASW flight profiles than the previously competing Kawasaki P-1. In effect, this means that the UK will be paying extra for wide-area Triton-assisted search capabilities which are not particularly relevant to the ASW-focused UK defence requirement. 

The off-the-shelf purchase of P-8 without UK-specific modifications will necessitate the purchase and stockpiling of new US Navy equipment and weapons to use with the aircraft. Furthermore, RAF Lossiemouth will need infrastructure capable of offloading mission data from the aircraft’s US systems and feeding it into the main UK intelligence network – which took time and investment to accomplish for the RAF’s other US-sourced ISTAR acquisition in recent years: the Airseeker. 

Finally, only US tankers are likely to be available to extend the P-8’s time on station when required since the RAF’s own Voyager multirole tanker transport aircraft cannot refuel the P-8 as they are equipped with a probe and drogue refuelling system rather than the US Air Force-standard flying boom. Nonetheless, the P-8 will bring an extremely potent ASW capability back to the RAF by 2019/20 which, alongside the wider MPA mission set that includes secondary tasks such as search-and-rescue surveillance missions, will fill a serious gap in UK power in a new era of confrontation with a revanchist Russia. Its sensor suite is superb, and with an onboard arsenal of US Navy-standard sonobuoys, aerial torpedoes and other weaponry, it will be a highly effective – albeit expensive – capability for the RAF.


Professor Justin Bronk

Senior Research Fellow, Airpower & Technology

Military Sciences

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