The programme to restore UK maritime patrol aircraft capability reached another milestone on 22nd July with the first weapon release from a British MRA1 Poseidon. The ability to both detect submarine targets and deliver torpedoes without warning at long ranges is one of the key advantages of the aircraft.
During a training flight over the Moray Firth not far from RAF Lossiemouth, a recoverable exercise variant torpedo (REXTORP) was dropped at low level. This unarmed weapon was released in a trial to prove the end-to-end process of the aircraft being tasked, equipped and making a simulated attack on a submarine.
To reduce the cost and the time involved in integrating the British-made Sting Ray lightweight torpedo (LWT), the UK has purchased Mk 54s off-the-shelf from the United States. Although this involves more UK defence spending overseas, the Mk 54 is already fully integrated with the Poseidon and stocks can be shared with US and Norwegian aircraft that will operate from RAF Lossiemouth and bases in, Iceland, Norway and the States. It is hoped the Sting Ray will eventually be integrated with P-8A (it also equips Norwegian Navy frigates and helicopters) but there is no commitment to do so at this stage.
Five torpedos can be carried in the Poseidon’s small weapons bay and will eventually be capable of being delivered from medium-high altitude, up to 30,000 feet, using a glider Kits. Boeing has the contract to build a glider kit for the Mk 54 torpedo, the High Altitude Anti-submarine warfare Weapon Capability (HAAWC). HAAWC integrates an air-launched accessory (ALA) kit with a GPS guidance system and folding wings. This will allow the launch of the weapon from up to 30,000ft under operator control so the torpedo can be put into the water with precision and at considerable distance from the aircraft.
The performance of torpedoes is highly classified but it is generally believed the latest Mod 1 Sting Ray is superior to the Mod 0 Mk 52, especially in complex littoral environments against small conventional submarines. The UK has an 11% stake in an $18.6M contract signed with Northrop Grumman in 2018 to enhance the Mk 54’s sonar array.
To date, five Poseidon MRA1s have been delivered by Boeing to the RAF, with the remaining four set to arrive by the end of this year. The Poseidon Strategic Facility is now fully operational after the £132M upgrade programme at RAF Lossiemouth which included a giant new hangar to accommodate 3 aircraft, a programme of runway resurfacing and apron enlargement.
Dropping the weapon is, of course, the relatively easy part of the ‘kill chain’. More importantly, the UK Poseidon force must be able to demonstrate they can detect, hold and classify deep submerged targets using a field of multi-static sonobuoys, although the performance in such trials are highly unlikely to be publicised.