FAA Expands Swift 100R Engine STC

Why It Matters

The expanded STC accelerates adoption of unleaded avgas, reducing lead emissions and positioning the general aviation market for the FAA’s 100LL phase‑out. It also gives operators greater fuel flexibility and mitigates supply risks.

Key Takeaways

• FAA expands 100R STC to dozens of engine models.
• Updated fuel specs effective Feb 19, 2026.
• 100R can be mixed with 100LL per guidelines.
• FAA aims to retire 100LL by 2030 nationwide.
• No single replacement fuel; multiple options under review.

Pulse Analysis

Swift Fuels' 100R unleaded avgas has moved a step closer to mainstream acceptance after the FAA broadened its Supplemental Type Certificate. By updating the fuel specifications and adding a wide array of Continental, Lycoming, Franklin and other powerplants, the agency removes a key barrier that limited the fuel to a single engine type. This regulatory shift not only validates Swift's technical work but also signals confidence in 100R’s performance and compatibility across the general aviation fleet.

For operators, the amendment translates into tangible operational benefits. The ability to intermix 100R with the legacy 100LL fuel, as long as Swift’s service instructions are followed, eases the logistical challenge of stocking a single fuel type during the transition period. Aircraft owners can now pursue the fuel switch without extensive airframe modifications, provided they secure the appropriate engine STC. This flexibility reduces downtime, cuts maintenance costs, and offers a clear pathway toward a lead‑free fuel regime, aligning with broader environmental goals.

The FAA’s broader transition roadmap underscores that 100R is one of several viable unleaded alternatives. By targeting the phase‑out of 100LL by 2030 nationwide—extending to 2032 in Alaska—the agency is fostering a competitive market where multiple fuels can vie for adoption based on performance, cost and infrastructure readiness. This multi‑fuel approach encourages innovation, supports regional supply chain development, and mitigates the risk of a single‑point failure in the national avgas ecosystem. Stakeholders should monitor upcoming approvals and infrastructure investments, as they will shape the pace and economics of the industry’s shift away from leaded aviation gasoline.