The P-8A is based on a commercial Boeing aircraft, the 737-800. (Similarly, the new KC-46A Tanker aerial-refueling aircraft, which is to replace the older KC-135 Stratotankers and KC-10 Extenders, is based on the commercial Boeing 767 design.)
The role of the P-8A is long-range antisubmarine and antisurface warfare, with more general intelligence, surveillance, and reconnaissance (ISR) missions thrown in for good measure.
The Navy will continue to make use of P-3C versions of the Orion along with the P-8A Poseidons for a while yet to come, in a phased replacement.
Based on the Global Hawk UAS and built with the Navy's BAMS program in mind, the Triton also comes with de-icing and lightning protection systems, along with reinforcements to the airframe and wing. "These capabilities allow the aircraft to descend through cloud layers to gain a closer view of ships and other targets at sea when needed," Northrop Grumman said. "The current sensor suite allows ships to be tracked over time by gathering information on their speed, location, and classification."
Boeing says that the P-8A has the fuselage of a 737-800 and the wings of a 737-900. The aerospace giant also has orders for the aircraft from India (for the P-8I derivative) and Australia.