Our story
Originally founded as S3 International in 2005 by Aksel Sidem, Jeff Wnuk, and Sebastien Imbert, S3 AeroDefense was built to deliver reliable, cost-effective aftermarket solutions for military aircraft operators worldwide. Backed by decades of combined aerospace experience, the company quickly became known for its experience, expertise, and customer-first approach.
Now operating from a 73,000-square-foot facility in Milwaukee, Wisconsin, S3 AeroDefense supports military aviation customers around the globe with OEM-authorized spares, repair services, and custom technical solutions. Strategic partnerships with industry-leading Original Equipment Manufacturers (OEM) including Honeywell, Moog, Collins Aerospace, and others have enabled S3 to expand its reach and deliver high-quality, OEM-direct and OEM-quality support across a wide range of military platforms.
With a growing global footprint, a commitment to excellence, and a focus on long-term partnerships, S3 AeroDefense continues to raise the standard for military aftermarket support—one mission-ready solution at a time.
s3 Mission & Vision
The principles guiding who we are and where we’re headed
Our Mission: Our purpose is to enhance the mission readiness of our aerospace and defense customers to meet their mission demands effectively.
Our Vision: To establish S3 AeroDefense as the premier global aerospace and defense company providing comprehensive aftermarket support to customers around the world through extensive relationships with original equipment manufacturers by creating solutions through superior customer support, uncompromising quality, and innovation.
company History
Two decades of meeting customers #WhereTheyAre
leadership team
Leadership Driving Innovation, Integrity, and Growth
company culture
Purpose, Performance, and People
S3’s company culture is built on a strong foundation of purpose, performance, and people. As a global leader in military aircraft sustainment, we know that delivering mission-critical support demands commitment, precision, and hustle. But just as important as the work we do is how we do it — together. From the sales floor to the shipping dock, our team brings energy and accountability to everything we touch, backed by a shared sense of pride in the customers and warfighters we support.
We embody a true work hard, play hard mentality — and not just as a catchphrase. Whether it’s solving complex MRO challenges, turning tight turnaround times on parts distribution, or onboarding a new OEM partner, our teams roll up their sleeves and get the job done.
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