Natural icing is a significant threat to inflight safety. This review article presents insights from our research and development processes related to flight tests in natural icing conditions. It begins with an overview of the airworthiness requirements for natural icing flight tests from various authorizations. Subsequently, key technologies associated with icing flight testing are discussed, providing a detailed analysis of the challenges encountered. The paper aims to consolidate knowledge in this critical area to enhance the safety and efficacy of conducting flight tests under natural icing conditions.