Overview

• The not-to-exceed $2,878,495,761 contract modification, managed by Naval Air Systems Command, covers propulsion systems, spares, and support for all three F‑35 variants.
• More than $2 billion was obligated at award across U.S. and international customers, with the U.S. Air Force share exceeding $614 million.
• Engine deliveries for Lot 18 will support U.S. services and partner nations, with 141 engines planned against 145 airframes under Lockheed Martin’s separate Lot 18 deal.
• Reported calculations place the Lot 18 average aircraft cost at roughly $101.5 million when combining airframe and engine, reflecting Technology Refresh 3 and Block 4 enhancements.
• Program leaders are pursuing an F135 Engine Core Upgrade after OMB declined to fund a separate adaptive-engine effort, sustaining a common engine across the fleet and its supplier base of about 67,000 U.S. jobs and 240 suppliers.