The 2nd International Hydrogen Aviation Conference (IHAC 2021) was held virtually on 2nd September 2021. The event was hosted at DoubleTree By Hilton Strathclyde, Glasgow, Scotland and was live-streamed to the registered participants for virtual attendance. During IHAC 2021, twenty-one excellent presentations were delivered by the Panellists, discussing the use of hydrogen in aviation. The morning Plenary Speech was offered by Mr. Bart Biebuyck, Executive Director, Fuel Cells and Hydrogen Joint Undertaking (FCH JU) and the afternoon Keynote Speech was delivered by Mr. Andy Marsh, CEO, Plug Power.