Boeing to upgrade more P-8A submarine hunters for U.S. Navy and Australia

The U.S. Navy has awarded Boeing a $119.7 million contract modification to buy nine more Increment 3 Block 2 retrofit kits for P-8A Poseidon maritime patrol aircraft, seven for the U.S. Navy and two for the Royal Australian Air Force, and to install four kits on U.S. Navy aircraft, the U.S. Department of War announced on Nov. 4.

The award is modification P00001 to order N0001926F1095 under basic ordering agreement N0001926G1002, and it exercises options for kits built to what Naval Air Systems Command calls Increment Three Block Two Engineering Change Proposal Six standard. The cost-plus-fixed-fee modification was not competed. Fiscal 2027 U.S. Navy aircraft procurement funds cover $110.2 million and Australian cooperative partner funds cover $9.5 million, all obligated at award, with work due to finish in May 2030.

The modification builds on a $121.2 million order NAVAIR issued under the same agreement in June, which bought nine Increment 3 Block 2 kits, six for the U.S. Navy and three for Australia, along with three installations on U.S. Navy aircraft and engineering work on parts that are going out of production. Together, the two actions fund 18 kits and seven U.S. Navy installations in less than five months.

The contract separates the A-kits Boeing will build from the B-kits it will install. An A-kit carries the permanent structural and electrical changes an aircraft needs to accept new equipment, such as racks, mounts, cabling and antenna fittings, while the B-kit is the mission equipment itself. In this award the B-kits are government-furnished, meaning the U.S. Navy buys that equipment separately and hands it to Boeing for installation. The announcement does not say when the Australian kits will be installed or where.

Most of the work, 79.6%, will be done in Jacksonville, Florida, where Boeing modifies P-8As at its Cecil Field facility. St. Louis, Missouri, accounts for 10.9% and Mesa, Arizona, for 9.5%.

Increment 3 Block 2 is the largest upgrade the P-8A has received since it entered service. The U.S. Navy declared initial operational capability for the configuration on April 24, 2026, after operational testing by Air Test and Evaluation Squadron One at Naval Air Station Patuxent River, Maryland. NAVAIR describes the upgrade as a significant change to the airframe and avionics, with new airframe racks, a new radome, antennas, sensors and wiring.

Inside the aircraft, the modification installs a new combat systems suite with more computer processing power, a higher-security computing architecture, wideband satellite communications, an anti-submarine warfare signals intelligence capability, a track management system, and additional communications and acoustic systems for search, detection and targeting. Aviation Week has reported that the package includes Multi-Static Active Coherent Enhanced processing, an improved version of the sonobuoy method in which some buoys emit sound pulses while others listen for echoes off a submarine hull. The U.S. Navy has not said whether the upgrade changes the AN/APS-154 Advanced Airborne Sensor radar that some P-8As carry.

Increment 1, fielded with the first squadron in 2013, reproduced the anti-submarine and anti-surface capabilities of the P-3C Orion the Poseidon replaced. Increment 2 added multistatic active coherent acoustics and the ability to drop torpedoes from high altitude using glide kits. Increment 3 Block 1 brought an open, network-ready avionics architecture, Link 16 and the Harpoon Block II+ anti-ship missile. NAVAIR’s P-8A program office, PMA-290, manages each step as a series of engineering change proposals, which is why the new kits carry an ECP number, and it describes Block 2 as the step that completes the full anti-submarine, anti-surface and surveillance capability set out in the aircraft’s original acquisition strategy.

The U.S. Navy began converting its fleet in March 2024, when it delivered the first P-8A to Boeing in Jacksonville for Increment 3 Block 2 modification, and Boeing rolled out the first upgraded aircraft in June 2025. Aviation Week has reported that the U.S. Navy has budgeted more than $3 billion for the upgrade across about 130 aircraft. Smaller orders continue alongside the kit buys; in April, Boeing received an $11.95 million modification to install one Increment 3 retrofit kit on a U.S. Navy aircraft.

Australia is the only international P-8A operator committed to Increment 3 Block 2 and pays for its share through a cooperative program with the U.S. Navy. The Royal Australian Air Force received its 13th Poseidon in September 2025, with a 14th and final aircraft scheduled for 2026, and in October 2025 Boeing inducted the first Australian aircraft into the upgrade. Boeing has said the first two Australian aircraft would be modified in Jacksonville and the rest by Boeing Defence Australia at RAAF Base Edinburgh in South Australia.