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In the current climate of public unrest and turmoil, there is an increasing need to improve the nation's defenses against all forms of conflict. To ensure absolute defense, all aspects of a nation's military arsenal have to be constantly updated. Such cases can be seen in the innovation arms race between radar sensing and stealth aircraft technologies.
In an attempt to upgrade the nation's military arsenal, the Boeing P-8A Poseidon Aircraft was added to the RAF fleet. This inclusion ends a 10-year-long absence of a maritime patrol aircraft since the Nimrod fleet was decommissioned in 2010.
There is a major advantage to maritime patrol in the ability to track and monitor hostile or friendly targets above and below the sea. The P-8A aircraft is set to join a fleet of marine aircraft and submarines to operate under very low-temperature conditions in the Arctic.
Boeing P-8A Poseidon Design
The P-8A Poseidon is a military aircraft based on a modified Boeing 737-800ERX originally designed for the United States Navy. The P-8A design originates from a need for a new surveillance aircraft that can operate at a much lower operating cost than the Lockheed P3-Orion.
A competition was started in 2000 for a new maritime patrol aircraft for which BAE systems proposed the Nimrod MRA4 and Boeing proposed a design based on the 737 airliners. The P-8A design was incrementally upgraded with legacy systems from the previous P3, and this proved effective as the incremental approach led to the product being under budget and on schedule.
This design varies from the commercial Boeing 737 airliner in several ways, having a longer fuselage of about 40m and a wingspan of 37m. It also features raked wingtips which help to reduce induced drag and the formation of wing-tip vortices. This leads to improved fuel efficiency and better take-off performance.
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Unlike a commercial 737 airliner, the P-8 requires a much larger output power system to power the onboard electronics which give it its superior surveillance capabilities. To compensate for the extra power needed, the P-8 is equipped with a 180KVA generator driven by its two engines. The new design resulted in an improved range and less turbulence during the flight.
P-8A Sensor Architecture
Besides the modified airframe, the P-8A Poseidon is equipped with a host of sensing and surveillance equipment which make it well-adapted for maritime patrol and submarine hunting. This includes an APY-10 radar by Raytheon for high-resolution mapping.
The APY-10 radar makes it possible to detect and track vessels above and below water (Raytheon Intelligence & Space, 2020). This model is an improvement on the previous APS-137 due to its reduced size and weight, increased target tracking capability and color weather avoidance mode.
This advanced radar is capable of detection, classification, and identification of small stationery vessels on water using the synthetic aperture radar (SAR) mode. This provides the crew with detailed battle damage assessment.
Small fast-moving vessels and surfaced submarines can be detected, classified and tracked using the high-resolution imaging synthetic aperture radar (ISAR) mode (Raytheon Intelligence & Space, 2020). The P-8A uses an acoustic sensor rather than the magnetic anomaly sensor used on the previous iterations due to the high operating altitude of the P-82 (41000 feet). It uses an active multi-static and passive acoustic sensor.
The P-8A Poseidon surveillance system also includes gyro-stabilized MX-20HD digital electro-optical/infrared multispectral sensor turrets capable of housing seven sensors; these sensors include CCDTV, laser range finder, image intensifier, and laser illuminator.
The MX-20 HD is a modular HD imaging system with large-aperture lenses for high magnification and a solid-state inertial measurement system for effective stabilization. This allows for long-range target optimization.
The P-8A achieves advanced sensing capabilities using passive and multi-static Sonobuoys, which can be deployed at high altitudes. A Sonobuoy is an expendable sonar detection system that is ejected from the P-8A. The P-8A deploys the Buoys in a canister and the inflatable float expands upon impact with the water to keep the buoys afloat.
Detection is carried out using hydrophone sensors deployed below the surface of the water, they contain a Piezoelectric transducer which generates an electric potential when subjected to a change in water pressure. This information is used to detect submarines in its vicinity and is then relayed back to P-8A via a radio UHF/VHF radio transmitter.
The P-8A advances its sensing capabilities using a UAV which can be launched from P-8A equipped with a Magnetic Anomaly Detection (MAD) sensor. Submerged submarines are detected by measuring small variations in the earth's magnetic field caused by the vessel.
In cases where hostile vessels are detected, the P-8A is capable of deploying a Mark 54 torpedo at an altitude of about 3000 ft by initially turning it into a glide bomb before impact. This is enabled by the High Altitude Anti-Submarine Warfare capability air launch accessory. The P-8A proves to be a key and necessary addition to the nation's maritime patrol fleet due to its advanced sensing and assault capabilities.
References and Further Reading
Allison, G. (2020) A look at the P-8 Poseidon, Britain’s new submarine hunter. [Online] ukdefencejournal. Available at: https://ukdefencejournal.org.uk/a-look-at-the-p-8-poseidon-britains-new-submarine-hunter/ (Accessed 13 April 2020).
Raytheon Intelligence & Space (2020) AN/APY-10 Maritime, Littoral and Overland Surveillance Radar. [Online] Available at: https://www.raytheonintelligenceandspace.com/capabilities/products/apy10 (Accessed 13 April 2020).
Daken, H. (2011) P-8A Poseidon: An Innovative Strategy for the Acquisition, Design, Manufacture, and Integration of Military Derivative Aircraft. International Conference on Aerospace Sciences and Aviation Technology, 14(AEROSPACE SCIENCES), pp.1-17.
Royal Air Force (2020) P-8A | Royal Airforce. [Online] Available at: https://www.raf.mod.uk/aircraft/p-8a (Accessed 11 April 2020).
Forces Network (2020) P-8A Poseidon: What Is The RAF's New Aircraft? [Online] Available at: https://www.forces.net/news/how-p-8a-poseidon-will-protect-uk (Accessed 13 April 2020).