The UK are investing in nine P-8A Poseidon Maritime Patrol Aircraft which will be called the 'Poseidon MRA Mk.1' in RAF service and eventually based at RAF Lossiemouth, Scotland, after major infrastructure and runway resurfacing work is completed.
It has been ten years since the Royal Air Force has operated the Nimrod MR2 Maritime Patrol Aircraft, and to maintain the skills required to operate Maritime Patrol Aircraft (MPA), the RAF had already embedded aircrew within MPA squadrons with the 'Seedcorn exchange programme' in Australia, Canada, New Zealand and the USA.
The first RAF Poseidon aircraft ('The Pride of Moray', ZP801) was officially delivered to the Royal Air Force on the 31st October 2019 and is operated from Naval Air Station Jacksonville in Florida, by 120 Squadron. This aircraft will cross the Atlantic and land in the UK at Kinloss Barracks in February 2020, as major work on RAF Lossiemouth runways and airfield operating surfaces will be underway from January 2020.
During June & July 2020 work at RAF Lossiemouth will focus on the intersection of the two runways and Typhoon operations will be temporarily relocated with 'Quick Reaction Alert' (QRA) Typhoon located to Leuchars and routine Typhoon flying moved to Kinloss Barracks.
By the end of 2020, RAF Poseidons will operate out of RAF Lossiemouth from the new strategic facility, maintained by the Poseidon Line Squadron and flown by 120 Squadron. All nine aircraft will be delivered by November 2021 and will form two squadrons at RAF Lossiemouth with 120 Squadron and 201 Squadron. It has also been announced that the United States Navy will routinely base their P-8 Poseidon aircraft at Lossiemouth alongside British aircraft.
The role of the Poseidon MRA Mk.1 will be to protect the UK's strategic nuclear deterrent as well as the Royal Navy's two new Queen Elizabeth class aircraft carriers. The Poseidon can provide long-range maritime reconnaisance, detect and prosecute enemy submarines or ships and carries 129 sonobuoys as well as Mk 54 torpedoes and can be fitted with Harpoon anti-ship missiles on four external wing mounted pylons. It can also provide long-range search and rescue.
The P-8A Poseidon is based on the Boeing 737-800 airliner but has a strengthened fuselage for low-altitude operations and raked wingtips. It is powered by two 27,000lb CFM turbofan engines, has a top speed of 490Kts (907Km/h), service ceiling of 41,000ft and a ferry range of 4,500 miles (7,242Km). There will be about eight crew which will consist of two Pilots, two Tactical Co-ordinators (Taccos) and four Weapon System Operators (two Acoustic & two Electronic Warfare operators).
The Poseidon has a comprehensive mission system using the sophisticated APY-10 radar with modes for high-resolution mapping, an acoustic sensor system, including passive and multi-static sonobuoys, electro-optical/IR turret and electronic support measures (ESM).
The last Maritime Patrol Aircraft operated by the Royal Air Force was the Nimrod MR1 & MR2 which were in service from the early 1970s until March 2010 and before that they operated the Avro Shackleton in this role. The Nimrod MRA4 was planned to replace the Nimrod MR2 but due to considerable delays, repeated cost overruns, and financial cutbacks, the development of the MRA4 was abandoned in 2010 as a result of the Strategic Defence and Security Review. The MRA4 had current-generation Rolls-Royce BR710 turbofan engines, a new larger wing, and fully refurbished fuselage.
Based on the de Havilland Comet, which was the world's first operational airliner, the Nimrod had four Rolls-Royce Spey turbofans, each with a thrust of 12,160lbs. The MR2 had a maximum speed of 500kts (580 mph, 930 km/h), service ceiling of 43,999ft, and range of 5,180 to 5,755 miles (8,336-9,262km) or ten hours, with around twelve or thirteen crew depending on the mission. To conserve fuel, two of the Nimrod's four engines could be shut down, once the weight was reduced by the consumption of onboard fuel. Later MR2's were fitted to receive mid-air refuelling in response to demands of the Falklands War. Unfortunately the RAF Voyager tanker is presently unable to refuel the new P-8 Poseidon as Voyager is equipped with a probe and drogue refuelling system rather than the US Air Force-standard flying boom.
The Nimrod MR1/2 was fitted with a Magnetic Anomaly Detector (MAD) in the tail of the aircraft which could detect submarines beneath the water, however the aircraft would need to fly very low and close to a submarine in order to detect it. The P-8 Poseidon does not have a Magnetic Anomaly Detector due to its higher operational altitude and instead uses its acoustic sensor system which is reportedly more effective at locating submarines. It should be noted however that India requested that their P-8I Poseidon aircraft be equipped with a Magnetic Anomaly Detector.
The Nimrod MR2 was equipped with the EMI Searchwater radar and featured a sizeable bomb bay which housed torpedoes, missiles and bombs as well as sonobuoys. The bomb bay could also fit additional fuel tanks or be used to deploy dinghies and droppable survival packs on a search & rescue mission. The Nimrod could also be fitted with two detachable pylons mounted underneath the wings to be used with missiles such as the Martel and two specialised pylons were later added to enable the equipping of Sidewinder air to air missiles.
Other versions of the Nimrod included the Nimrod R1 which was operated by the RAF in the signals intelligence role. Three Nimrod R1 aircraft were used in this role until they were retired in June 2011 and were then replaced by three Boeing RC-135W Rivet Joint aircraft from late 2013. In the mid 1970s, it was also proposed that an Airborne Early Warning (AEW) version of the Nimrod should replace the Shackleton AEW.2 but was plagued by cost over-runs and problems with its GEC 4080M computer and it was cancelled in December 1986. The Royal Air Force eventually received seven Boeing E-3 Sentry aircraft instead.