The 100th Boeing P-8 Poseidon maritime patrol aircraft has entered final assembly. The milestone aircraft, which is currently in the process of receiving its wings and tail at Boeing’s plant in Renton, Washington, will be delivered to the U.S. Navy this autumn.

The milestone comes as Boeing works with the U.S. government to further expand the customer base for the maritime patroller, which is slowly edging the long-serving Lockheed P-3 Orion out from front-line use. Boeing is currently producing aircraft for Australia and the U.S. Navy and is preparing to build four aircraft for India as part of a follow-up order for that navy’s bespoke fleet. Meanwhile long-lead components for the five P-8s destined for Norway have also been contracted.

Meanwhile the fuselage for the first of nine British aircraft will be built later this year and will enter final assembly in early 2019.

Boeing is facing competition from companies like Saab offering converted business like its Global Express-based Swordfish. Japan is also heavily marketing its Kawasaki P-1 platform to potential customers.

Boeing is currently building 18 P-8s a year.

“The Navy is certifying air-to-air refueling and has begun training crews to perform it,” adds Matt Carreon, Boeing’s P-8 global sales and marketing lead.

Carreon envisions that 200 aircraft could be delivered to the U.S. Navy and FMS customers.