Background The COVID-19 pandemic has placed exceptional demand on Intensive Care Units, necessitating the critical care transfer of patients on a regional and national scale. Performing these transfers required specialist expertise and involved moving patients over significant distances. Air Ambulance Kent Surrey Sussex (AAKSS) created a designed critical care transfer team and was one of the first civilian air ambulances in the United Kingdom to move ventilated COVID-19 patients by air. We describe the practical set up of such a service and the key lessons learned from the first 50 transfers. Methods Retrospective review of air critical care transfer service set up and case review of first 50 transfers. Results We describe key elements of the critical care transfer service, including coordination and activation; case interrogation; workforce; training; equipment; aircraft modifications; human factors and clinical governance. A total of 50 missions are described between 18 December 2020 and 1 February 2021. The mean age of these patients was 58 years (29–83). 30 (60%) were male and 20 (40%) were female. The mean total mission cycle (time of referral until the time team declared free at receiving hospital) was 264 minutes (range 149–440 min). The mean time spent at the referring hospital prior to leaving for the receiving unit was 72 minutes (31–158). The mean transfer transit time between referring and receiving units was 72 minutes (9–182). Conclusion Critically ill COVID-19 patients have highly complex medical needs during transport. Critical care transfer of COVID-19-positive patients by civilian HEMS services, including air-transfer, can be achieved safely with specific planning, protocols and pre-cautions. Regional planning of COVID-19 critical care transfers is required to optimise the time available of critical care transfer teams.