Airbus has revealed its latest ZeroE hydrogen airliner design, featuring enhancements for energy efficiency by opting for four open rotor engines instead of six. The design changes are aimed at improving the aircraft's overall performance and minimizing environmental impacts. However, Airbus has admitted that the certification of hydrogen-powered airliners may face delays, with the target year of 2035 likely to be surpassed. Despite the challenges, the aerospace industry is actively pursuing advancements in technology for both commercial airliners and military aircraft, with significant investments in research and development. Engine manufacturers like GE Aerospace and CFM are increasing their production capacity to meet the demand for engines, particularly the CFM Leap engines. Recent orders from Chinese leasing groups and airlines at events like the Farnborough Airshow and Singapore Airshow highlight the industry's focus on engine advancements and sustainability. The push for decarbonization in the aviation sector is driving engine makers to explore various paths, balancing short-term efficiency improvements with long-term solutions for achieving sustainability goals in the 2030s.