What is the fine-grained topic of the following text: The Federal Aviation Administration has confirmed that SAJF is safe to use - a mixture of biofuels from renewable sources with Jet-A is equivalent in performance to a “clean” Jet-A and does not require any modifications to the aircraft’s propulsion system. Only return the topic.
Federal Aviation Administration's confirmation on the safety and performance of SAJF biofuels in aircraft propulsion systems.