FAA Approves Unleaded Avgas for Expanded List of General Aviation Aircraft
In a significant stride towards eradicating leaded fuel from general aviation, the Federal Aviation Administration (FAA) has broadened the list of piston aircraft authorized to operate on Swift Fuels’ 100R unleaded aviation gasoline. The expansion includes over 1,200 engine models and 1,600 airframe models to the fuel’s existing Supplemental Type Certificate (STC).
The enlarged Approved Model List (AML), managed by the FAA’s Central Certification Branch, now encompasses engines from over 80 manufacturers. This includes approximately 395 Lycoming models, 195 Continental models, 95 Curtiss-Wright models, and 95 Pratt & Whitney models. On the airframe side, the list comprises roughly 118 Cessna aircraft, 101 Beechcraft models, and 98 Piper aircraft, among numerous others. Collectively, these Phase 1 approvals represent aircraft that currently consume up to 56% of all 100LL leaded avgas used across the United States.
Swift Fuels’ 100R, conforming to the ASTM International fuel specification D8603, is presently the only commercially available 100-octane unleaded aviation fuel approved under FAA STCs. The company’s proprietary formula merges hydrocarbons and ETBE and includes its Swift AvADD additive. This additive is designed to eliminate lead fouling, reduce engine wear, and extend engine life. Swift Fuels has announced its aim of completing full 100R engine certification by the end of 2027 or early 2028, aligning with the U.S. government’s mandate to transition to unleaded avgas by 2030.
Source: General Aviation News – July 16, 2026