What is the primary cause of structural failure in aircraft under stress?

The primary cause of structural failure in aircraft under stress is material fatigue due to repeated loading. This phenomenon occurs when a material experiences fluctuating loads over time, leading to the development of microscopic cracks that can grow and propagate under continuous stress. As aircraft undergo various phases of flight, including takeoff, landing, and maneuvers, components are subjected to cyclical loads. Over time, these repeated stress cycles can weaken the structure, ultimately resulting in failure.

Understanding material fatigue is crucial in aviation maintenance, as it emphasizes the importance of regular inspections, maintenance, and adherence to operational limitations to ensure the longevity and safety of aircraft structures. The emphasis on material fatigue highlights the significance of monitoring the aircraft's service life and maintaining awareness of the number of takeoff and landing cycles, as each cycle contributes to the wear and tear of structural components.

While excessive weight during takeoff, poor aircraft design, and insufficient maintenance checks can contribute to different types of operational issues or failures, they are not the primary cause of structural collapse when considering the impact of repeated stress cycles and the fatigue they induce on materials over time.