This whitepaper provides a comprehensive examination of how Advanced Persistent Threat (APT) groups exploit vulnerabilities in the aviation sector. It outlines the complex attack surface that includes airlines, airport operations, and aircraft systems, emphasizing the significant risks posed by cyber attacks. The document details various APT groups, including those from China, Russia, Iran, and North Korea, which have been identified as major threats to the aviation industry. It discusses notable incidents of cyber attacks, such as ransomware and Distributed Denial of Service (DDoS) attacks, highlighting the methods employed by these groups. The paper also addresses the challenges faced by Chief Information Security Officers (CISOs) in mitigating these threats and suggests strategic recommendations for enhancing security measures. The increasing reliance on cloud services and the impact of remote working on the attack surface are also examined, underscoring the evolving nature of cybersecurity risks in the aviation sector.