Lockheed Martin has approved Synthetic Aviation Turbine Fuels (SATFs) as safe to fly in the F-35 fighter, a potential boon for the Air Force’s energy and climate goals.
The announcement coincides with Norway demonstrating the first use of SATFs in its F-35s.
After “comprehensive technical and strategic analysis to ensure SATF meets the strict performance and reliability standards required for the F-35’s complex, high-demand missions,” Lockheed decided there was no technical risk, a spokesperson said, as long as SATFs comprise no more than 50 percent of the fuel load mix with standard fuel. The 50 percent limit is dependent on “the type of raw materials and production pathway.”
SATFs derive from both fossil-based sources such as coal and gas as well as renewables or recyclables like agricultural products and waste oil.
“The new fuel sources will improve readiness by reducing reliance on the extended supply chain,” Lockheed said.
With the approval, U.S. F-35s could fly using SATFs during deployments to Norway, when the host country provides fuel for joint exercises.
“The integration of SATF supports the Department of Defense’s objectives for energy substitution and diversification while enhancing energy resilience and operational flexibility,” the company added.
Norway made the first F-35 flights with SATF on Jan. 14; the fuel load included a 60/40 mix of standard jet fuel and what the Norwegian defense ministry described as “biofuels.”
Defense Minister Bjorn Arild Gram said that Norway’s air force accounts for a third of the defense ministry’s carbon emissions. Switching to a more sustainable blend will “reduce emissions and strengthen supply security,” he said in a press release. “The aim is to achieve climate targets while enhancing preparedness.”
Gram also said Norway has a new defense plan that calls for “significantly increased” activity of its armed forces. SATF could help accomplish that while curbing the military’s climate impact. Norway has about 40 of the 52 F-35s it plans to field by the late 2020s.
In the mid-2000s, the U.S. Air Force invested in a synthetic jet fuel capability using the Fischer-Tropsch method and tested the resultant fuels on a C-17 and on a B-52. Then-Air Force Secretary Mike Wynne pursued the technology because of the excessive cost of aviation fuel at the time and concern that the Air Force—the Defense Department’s largest user of fuel—might run short during a national crisis. The method explored converting coal and other materials into aviation-grade fuel.
A B-52 flown in September 2006 ran two engines on a synthetic fuel blend and the other six engines on JP-8. Two months later, the B-52 ran all eight engines on the synthetic fuel blend.
The Air Force was not immediately able to describe its current capability to produce synthetic fuel. As recently as 2021, it partnered with private companies to produce aviation fuels from carbon using the Fischer-Tropsch method. And in its 2022 Climate Action Plan, the service laid out a goal of creating a pilot program to ensure that by 2026, 10 percent of the aviation fuel at two Air Force operational locations is sustainable and costs the same or less than traditional fuel.
With an annual consumption of about two billion gallons of aviation fuel, any reduction in the unit cost per gallon of fuel could be significant for the Air Force budget.