A United Airlines Boeing 737 Max 8 flight due to push back from the gate at Chicago O’Hare Airport at 1 p.m. local time Wednesday and fly to Washington Reagan National Airport will mark two important milestones in the aviation industry’s effort to qualify 100 percent drop-in sustainable aviation fuel (SAF) for commercial flights.
As a 50 percent partner in the CFM International joint venture, which makes the Leap-1B engines powering the 737 Max 8, GE Aviation has provided key support to United’s December 1 SAF demonstration-flight initiative. GE has been working on SAF development and standardization for commercial flights since 2007.
Gurhan Andac, GE Aviation’s fuels and additives leader, told AIN the United flight will boost the industry’s SAF qualification and standardization effort in several ways. As the first-ever flight fueled by 100 percent SAF to carry passengers rather than only essential personnel, the event should help encourage other airlines, operators, and industry partners to focus strongly on SAF operational initiatives, said Andac, who serves as the chair of the ASTM International industry committee working to develop and qualify drop-in 100 percent SAF.
Plans called for the flight to carry more than 100 passengers—though none will be fare-paying. One high-profile passenger expected on the flight is United CEO Scott Kirby and another is Andac. United operated a previous 100 percent SAF flight in October, carrying only essential personnel, to obtain the data needed for FAA permission to operate Wednesday’s passenger-carrying flight.
The United flight also marks the first fueled by 100 percent drop-in SAF, not just 100 percent SAF. In this context, “drop-in” means the 100 percent SAF is identical in composition to conventional jet fuel and can be used without modification in any turbine engine and in any fuel infrastructure for jet fuel.
While today’s industry standard allows the operation of commercial flights using jet fuel blends containing up to 50 percent SAF, Andac said, the December 1 flight will provide “a significant tactical benefit” for the industry’s effort to standardize and qualify 100 percent drop-in SAF for commercial aviation operations. It should also “open the door” to let producers blend individual components to create 100 percent SAF, which so far has not gained approval.
Andac added that the United demo flight will further the case for blending of different SAF components because the 100 percent drop-in SAF developed for and allowed by the FAA for the flight is a blend of SAFs produced by two conversion pathways. The first blend is HEFA-SPK, synthetic paraffinic kerosene produced from hydroprocessed fatty acids and esters. The second blend is SAK, synthetic aromatic kerosene.