Helios Airways Flight 522 was operating a flight from Larnaca, Cyprus to Prague, Czech Republic, with a planned stop in Athens, Greece. Shortly after taking off from Larnaca on August 14, 2005, the Boeing 737-300 experienced a loss of cabin pressure, which incapacitated both the crew and the passengers due to hypoxia. As the aircraft continued to fly on autopilot, air traffic control and ground personnel in Athens became increasingly concerned about the unresponsive plane. The pilots failed to follow emergency protocols that could have increased cabin pressure, leading to tragic consequences.

The aircraft flew aimlessly for over two hours without human control and eventually began to descend due to fuel exhaustion. Upon reaching the vicinity of Grammatiko, Greece, it crashed into mountainous terrain. Authorities responded promptly, but unfortunately, there were no survivors among the 121 individuals, including passengers and crew members. The subsequent investigation identified a series of errors in both the maintenance protocols and the airline's operations that contributed to the disaster, prompting significant changes in aviation safety regulations.

This incident led to increased scrutiny over airline safety standards in Cyprus and around the world. It highlighted the importance of stringent maintenance practices and the need for thorough training and adherence to emergency procedures for flight crews. The disaster became a pivotal moment for Helios Airways, which faced serious operational challenges following the crash, leading to heightened awareness regarding the safety protocols in the aviation industry.