In June 2024, Joby, a U.S.-headquartered company, successfully completed the inaugural flight of its 2.5-ton tiltrotor eVTOL S4. This cutting-edge aircraft is powered by a water-cooled liquid hydrogen system. Carrying 40 kg of liquid hydrogen fuel, the S4 soared through the skies for an impressive 4 hours and 47 minutes, covering a remarkable distance of 841 km. Upon landing, it still retained 10% of its fuel—a feat that showcases three times the endurance compared to its all-electric counterparts.

The S4 boasts a turbo-electric hybrid powertrain, seamlessly integrated with six tiltable electric propellers. This innovative design enables the aircraft to perform vertical takeoffs and landings with ease, while also achieving efficient cruising capabilities. Joby's S4 has already secured airworthiness certification from the Federal Aviation Administration (FAA), paving the way for its commercial debut. The company has set its sights on launching commercial services in Dubai by 2025 and is actively collaborating with industry giants like Toyota and Uber to accelerate the deployment of this groundbreaking technology.