What is a common consequence of ignoring fatigue in aircraft metal structures?

Ignoring fatigue in aircraft metal structures can lead to rapid structural failure. Fatigue is a progressive and localized structural damage that occurs when a material is subjected to cyclic loading, which is common in aircraft due to take-offs, turbulence, and landings. Over time, this cyclic stress can cause micro-cracks to form in the metal. If left unaddressed, these cracks can propagate rapidly, compromising the integrity of the aircraft structure and potentially leading to catastrophic failures during operation.

Understanding the importance of regular inspections and adherence to maintenance protocols is critical for ensuring the safety and longevity of aircraft. By recognizing and addressing signs of fatigue early on, structural failures can be prevented, thus maintaining operational safety and reliability.

In contrast, the other options highlight outcomes that do not result from ignoring fatigue. Improved fuel efficiency, better handling during flight, and increased maintenance costs may not be directly related to the consequences of neglecting structural fatigue. Instead, neglecting this critical aspect of aircraft maintenance primarily invites the risk of sudden and severe failures, emphasizing the necessity for vigilance in inspecting and repairing metal structures within aircraft.