As part of its ongoing efforts to develop an acceptable unleaded fuel for small airplanes, the FAA announced that it has selected two unleaded fuels for PHASE 2. Fuel formulations from Shell and Swift Fuels were selected for Phase 2 engine and aircraft testing. Test data will help the companies obtain an ASTM International Production Specification for their fuels and allow the FAA to authorize the existing GA fleet to use the unleaded replacement fuels. Phase 2 testing will begin this summer and conclude in 2018.
The full text of the FAA press release can be found by clicking here.