“Nine new Boeing P-8 Poseidon Maritime Patrol Aircraft to increase further the protection of our nuclear deterrent and our new aircraft carriers. These aircraft will be based in Scotland and will also have an overland surveillance capability.”

In welcome news for many,the last Strategic Defence and Security review confirmed that the United Kingdom will once again operate an effective maritime patrol aircraft.

The P-8 Poseidon, developed by Boeing, is designed to conduct anti-submarine warfare (ASW), anti-surface warfare (ASUW), and shipping interdiction, along with an electronic signals intelligence (ELINT) role. This involves carrying torpedoes, anti-ship missiles and other weapons.

The history of the aircraft dates back to June 2004, when the US Navy announced the selection of the Boeing multimission maritime aircraft, 737 MMA, and awarded a contract to Boeing for the system development and demonstration phase of the programme for the US Navy’s next-generation maritime surveillance aircraft. The aircraft was given the designation P-8A in March 2005.

Poseidon contains up to 7 crew computer consoles in its cabin, has an electro-optical and infrared sensor turret, a maritime surveillance radar and signal intelligence system. Its radar is capable of detection, classification and identification of ships, small vessels and surfaced submarines.

It also has coastal surveillance capability. The P-8 is fitted with advanced magnetic anomaly detection system for submarine tracking. The Poseidon can be used for search and rescue operations.

According to the US Navy, the aircraft in US service carries lightweight Raytheon Mk54 anti-submarine torpedoes. It may also carry other torpedoes, missiles, free-fall bombs, depth charges, mines, or sonbuoys in its weapon bay. Air-to-surface and air-to air missiles, such as Harpoon anti-ship missiles, SLAM or AGM-65 Maverick land attack missiles, and AIM-9 Sidewinders or AIM-120 AMRAAMs will be carried on the underwing hardpoints.

It has been speculated that the UK may elect to integrate Storm Shadow on the aircraft, as it had planned to do with Nimrod prior to the cancellation of the aircraft.

It is expected that up to 117 P-8A MMA aircraft are to be purchased by the US Navy to replace the fleet of 196 P-3C Orion maritime patrol aircraft which are approaching the end of their operational lives. The initial operational capability of P-8A was achieved in November 2013.

In August 2012, it was first reported that Boeing saw the United Kingdom as a market for the P-8, following the cancellation of Nimrod MRA4. After speculation every few months that the UK was going to purchase the aircraft, the UK announced its intention to order nine P-8 aircraft.

P-8 Poseidon Quick Facts, courtesy of Boeing

  • For the P-8, Boeing uses a first-in-industry in-line production system that leverages the best of Boeing Commercial and Boeing Defense for development and production.
  • The P-8 can fly up to 41,000 feet and travel up to 490 knots.
  • P-8 offers higher reliability – the 737 has a 99.8 percent dispatch rate, with more than 4,000 aircraft flying, and 6,600+ orders.
  • The P-8 is engineered for 25 years/25,000 hours in the harshest maritime flight regimes, including extended operations in icing environments.
  • The P-8 can fly in all flight regimes, and can self-deploy up to 4,500 miles from base without refueling.
  • Dual CFM-56B commercial engines each provide 27,000 pounds of thrust, greatly enhancing climb and flight characteristics over turboprop equipped aircraft.
  • Each engine is equipped with a 180KVA engine driven generator.  Combined with the 90KVA commercial APU, this provides 450KVA of power. P-8 possesses significant growth capacity for equipment with excess onboard power and cooling capacity.
  • P-8 has twice the sonobuoy processing capability and can carry 30 percent more sonobuoys than any maritime patrol and reconnaissance aircraft currently flying.
  • P-8 has the ability to control unmanned air vehicles (level 2 control-receive) to extend sensor reach.
  • P-8 offers commonality with 737 fleet and other military platforms that use the 737 airframe.

The aircraft are to be based at RAF Lossiemouth in Scotland and be used to protect the UK’s nuclear deterrent and new aircraft carriers. The P-8s are also to perform search-and-rescue missions and conduct overland reconnaissance.

Three P-8 Poseidon aircraft are to be in service before 2020.


  1. It’s a shame we have no plans to pair these with something like triton, that would really mitigate the low numbers and work very well. A p-8 or two gives you little ability to monitor UK waters effectively, but add in a few Tritons to the mix with their endurance and your capably goes up a notch.

  2. They carry about 20 tons of kit; that’s a lot of ASW. But they burn 20 tons of fuel for only 4 hours on station. If we find a sub to kill they’re great to get out there quick and help, but for 24/7/365 hunting these 9 aircraft just won’t be able to do it. They are also costing us £3bn which would be enough for 4 more Astutes which could do a 24/7/365 job.

  3. Compared to the Nimrod they are slower and have a shorter range. They also have a smaller weapon load and it doesn’t support probe and drogue aerial refuelling.
    There was once a plan to use the frame of the 146 regional jet by BAE but it didn’t get any support from the MOD. I still find it hard to believe that we could not build a Nimrod replacement that not only met the same capability but would have been cheaper. The MR4 avionics suite was world class at the time, but just needed a better frame to put it in.
    We were lucky that the aircraft wasn’t needed in the interim.

  4. British Government should have opted for Japanese Kawasaki P1 with RR RB715 engines and the kit from the MR4 installed. Overall I think the Kawasaki is a better maritime aircraft than the Boeing P8

    • In the short term your Anglo P1 would make an excellent aircraft, unfortunately the cost would be enormous and 15 years from now we would have to pay another fortune out on mid life upgrades to counter obsolescence , just as we would have had to do with the MR4, with only the UK tax payer to foot the bill

  5. Refuelling??

    Are we really going to only refuel these with ou4 partners who had the foresight to fit their air to air refuelling with drogues and booms

    AirTanket PFI – what a governmental cock-up!!!!!!!!

  6. I never realised just how many and what variety of weapons these can carry. With ground surveillance these are lethal anywhere on earth from stand off ranges and have the power for laser defences.

  7. Pros and cons to this aircraft Vs Nimrod and Kawasaki P1.
    I would feel better if the RAF was getting more than 9 aircraft. Say another 5-6 should provide enough capacity to effectively patrol UK EEZ
    I think a maritime patrol UAV is needed for longer loiter and endurance

  8. There seems to be some disagreement on on-line forums as to whether the P8 will be fitted with MAD. It certainly will not have the tail boom usually associated with such a system and the higher operating altitude the P8 is designed for would seem to preclude its use. I have also seen suggestion of the development of a small uas that could be deployed from a P8 that would add a MAD capability.

    • The simple answer to a MAD boom is no, unless uncle Sam fits them to his.

      Ours will remain stock US Navy spec. An imminently sensible and cost-effective solution.

  9. Why did 2010 happen with all the disaster that came with it? I feel cuts back then were being made to show something was being done, like the Sheffield Forgemasters loan and others. Little do politicians know that most of this just depresses people. Seeing Nimrods being torn apart helps no one, and I am sure this was done outside for others to see, for a reason.

    • Lib-Con government wanted to save money so they do what all governments do. Take a hatchet to the MoD.

      I voted for that government to end 13 years of our forces being run into the ground by Labour.
      It was a real slap in the face.

  10. If the UK does not want to pay to integrate Storm Shadow on the P-8, I note that SLAM-ER is back in production for a big Saudi order (650 missiles). Might not be a bad idea for the MoD to tack on a few for the RAF while the production line is open.

  11. So we are spending billions on an ASW aircraft that can only carry a handful of ASW weapons and those weapons, the Mk54, have a very dubious capability against subs.
    You couldn’t dream it up.
    Forget integrating Storm Shadow or Harpoon.. just get Mk 75 Sting Ray integrated ASAP.
    There is not a lot of point in having an aircraft designed to kill subs that is armed with a weapon that struggles to do the job.


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