A situation where an aircraft operates outside the parameters of a clearance, regulation, or published procedure. This encompasses a broad range of occurrences, from minor altitude or heading variations to more serious incursions into restricted airspace or runway incidents. For example, an aircraft instructed to maintain a specific altitude that instead drifts significantly higher or lower would be considered an instance of this.
Understanding and addressing such occurrences is crucial for maintaining aviation safety. Analyzing events allows for the identification of contributing factors, such as miscommunication, navigational errors, or equipment malfunctions. This analysis then informs improvements to training programs, air traffic control procedures, and aircraft technology, ultimately reducing the likelihood of future incidents. The historical record of aviation is marked by the continuous evolution of safety measures driven by learning from past events.
