Restoring the UK’s maritime patrol aircraft capability (Part 3)

In two previous articles (written in 2017) we covered the background, procurement, design and equipping of the Poseidon MRA1 Maritime Patrol Aircraft being purchased by the RAF. With two of the nine aircraft having arrived in the UK in so far, here we provide an update on the progress of this project that is critical to UK naval operations.


Despite the global crisis, on 3 April the RAF formally declared Initial Operating Capability (IOC) for the Poseidon. The first aircraft (call sign STINGRAY01) is participating in a much-reduced version of exercise Joint Warrior being conducted off the western coast of Scotland. Although very early days, this is the first step on restoring a vital part of the UK ability to monitor Russian submarine activity without reliance on foreign MPAs. Poseidon will also give back the ability to conduct long-range search and rescue support to distressed mariners far out to sea.

The first UK Poseidon aircraft named “Pride of Moray”, aircraft number ZP801 completed its first flight in from Renton, Washington State on 12 July 2019. After completion of test flying, the aircraft was delivered to Boeing’s P-8 Installation and Checkout facility in Tukwila, where mission systems were installed. After further testing, in October 2019 it was flown across the US to Naval Air Station Jacksonville, in Florida where RAF crews did initial training and preparation with VP-30 the US Navy’s Poseidon Conversion Squadron. The first fully RAF-crewed sortie was flown by ZP801 on 4th December.

ZP801 subsequently crossed the Atlantic, touching down at Kinloss Barracks on 4th of February where it was welcomed by the Minister for Defence Procurement, senior RAF and Naval officers, invited media and a host of aviation photographers.

Like the F-35, Poseidon is manufactured in ‘Lots’ (batches) of aircraft for various international customers. The UK will have received 3 aircraft from Lot 8 by the end of 2020 and the remaining 6 aircraft from Lot 9 due will have been delivered to the UK by the end of 2022. Interim operating capability is planned for September 2021 and full operating capability with the nine aircraft is scheduled for April 2024.

  • Pride of Moray approaching Kinloss, February 2020 (Photo: Apple Bear via Flickr)

  • Pride of Moray welcomed on her first arrival at Kinloss, 4th February 2020.

  • Flypast

  • The second aircraft City of Elgin ZP802 made its first flight on the 19th September and arrived at Kinloss on 13th March 2020.

  • Taxiing on arrival.

The Poseidon Strategic Facility

Of the £3 billion the UK is investing in recapitalising its MPA capability, £132 million is being spent on upgrading its main operating base at RAF Lossiemouth. The Lossiemouth Development Programme has been a complex planning and logistical project and had to ensure that it did not interfere with the station’s mandated output as base for the Typhoon aircraft held in readiness for Quick Reaction Alert (North).

The work is progressing well but until it is complete, the two aircraft are temporarily operating from the former RAF Kinloss Nimrod base (subsequently handed over to the Army and re-named Kinloss Barracks). The vast Poseidon Strategic Facility at Lossiemouth is being part-funded by Boeing. The hangar will accommodate 3 aircraft at once and includes new Squadron accommodation, crew and maintainer training facilities, flight planning facilities and workshop areas.

The runways at Lossiemouth were originally designed for fast-jets rather than larger multi-engine aircraft and are being resurfaced and widened in a programme of works throughout 2020. In November a Poseidon aircraft will land at RAF Lossiemouth for the first time and the new base will be formally opened with the resurfacing work to be fully complete by 2021.

The P8-A is an international programme and the UK will benefit by participating in future upgrade programmes which will share development costs. 13 UK based companies are producing components for P-8A, making up about 5% of all aircraft manufactured globally. The auxiliary fuel tanks are made by Marshalls of Cambridge. The bird-strike resistant, lightweight windscreens and large observer windows are made by GKN. Martin Baker UK manufactures the seats in the aircraft and GE make the weapons pylons.

  • 2,500 tonnes of steel and 100,000 tonnes of concrete, have gone into the construction of the vast Poseidon Strategic Facility that is 19 metres in height, 165 metres in length and 100 metres wide. (November 2019)

  • The squadron offices and workshops wrap around the side and rear of the vast hangars.

  • Construction well advanced, November 2017.


120 and 201 will be the two frontline RAF squadrons flying the MRA1. Each squadron will have 9 crews. Each crew consists of eight people; 2 pilots, 2 Tactical Coordinators (TACCOS) and 4 Weapon System Operators (WSOp – 2 Acoustic and 2 Electronic Warfare specialists). The first aircraft are allocated to 120 (CXX) Squadron with 201 due to stand up in 2021. The Poseidon Line Squadron will be responsible for maintaining the aircraft. 54 Squadron (Poseidon Flight) will be the Operational Conversion Unit based at Lossiemouth (54 Squadron is the parent OCU for all RAF ISTAR aircraft based at Waddington). The first crews have been trained with VP-30 at NAS Jacksonville in Florida but training will switch to the UK in 2021.

RAF instructors serve with VP-30 and RAF personnel are also embedded with Air Test and Evaluation Squadron VX-1 at NAS Patuxent River supporting the aircraft’s development programme. VX-1 also contributes expertise to TRINATS, the Five-Eyes MPA trials and testing cooperation forum. As a member of the Five-Eyes intelligence alliance, the UK benefits from shared international expertise and experience of MPA and ASW operations via this forum.


Poseidon has a mission endurance of about 10 hours, potentially it could fly 1,200 nautical miles to the assigned patrol area and spend 4 hours on station before returning. Typical transit at high altitude would be at 340 knots (true air speed) with a ‘dash’ speed at high level of 400 knots and 300 knots at low level. The Aircraft is reportedly very stable and smooth at both low and high altitude which is important in reducing crew fatigue.

As standard “increment 3” aircraft the MPA1 are not yet fitted with a full suite of defensive countermeasures and has US-style boom air-air refuelling system. For in-flight refuelling, they will be reliant on available USAF tankers as the RAF’s Voyager MRTT drogue AAR system is incompatible. Flying from Lossiemouth and returning without in-flight refuelling, the MRA1 has the potential range to patrol the seas off Greenland to the North West, the Barents Sea to the North East or as far South as Sardinia in the Mediterranean. The MRA1’s range and endurance is comparable with the Nimrod MR2 that it replaces although the Nimrods were much more numerous and could refuel from the RAF tankers of the time.

The UK Aircraft will have access to NATO airbases which will allow them to refuel and in some cases re-arm or replenish sonobuoy stocks. In the main North Atlantic and Arctic theatres, co-operation agreements are already in place that will allow US, Norwegian and British Poseidons to share the support facilities at Evenes in Northern Norway, Keflavik, Iceland and RAF Lossiemouth.

The capabilities of Poseidon are covered in more depth here. Although expensive, it is undoubtedly the best MPA in the world due to its advanced onboard sensors and powerful processing capabilities in combination with Multi-Static Active Coherent (MAC) Sonobuoys, of which it can carry 129. With just 9 MRA1 aircraft, quality has triumphed over quantity (The RAF was originally supposed to receive 24 MRA4 Nimrods) but this is the best choice within the £3Bn budget. There may be fewer Russian submarines in the North Atlantic than when MRA4 was conceived but they are generally quieter and harder to detect.

The schedules and plans discussed in this article are likely to be subject to effects from the COVID-19 crisis. Boeing shut all its aircraft manufacturing facilities in Seattle on 24th March indefinitely. The entire global commercial aviation sector has suffered a profound shock. Even when life returns to something approaching normality, international air travel is likely to be much reduced. Demand for new commercial aircraft will probably almost vanish for a time and the effects of this on the aerospace industry are likely to ripple out across the military aviation supply chain.

As the global pandemic took hold, in March 2020 seven RN vessels were involved in shadowing an unusually large number of Russian warships near UK waters. At the same time, this was accompanied by increased Russian air activity close to the UK. Our nearest adversary continues to probe and test defences and there can be no let-up in vigilance. Declaring IOC for MRA1 and dispatching an aircraft on patrol and to participate in ASW exercises demonstrates the UK has not let its guard down.


(Main image: Photoshop composite)