What are some indicators of structural distress in aircraft?

Structural distress in aircraft often manifests through specific physical changes or irregularities that indicate underlying issues with the airframe or components. Cracking, deformation, and unusual sounds are direct indicators of potential structural problems. Cracking may suggest fatigue or stress beyond the material’s limits, while deformation can indicate bending, warping, or failure of components due to excessive loads or impacts. Unusual sounds can also hint at problems; for instance, they might signify loose or damaged parts, indicating that the structural integrity may be compromised. Recognizing these signs is critical for maintenance personnel to ensure the safety and reliability of the aircraft.

The other options, while related to aircraft conditions, do not serve as direct indicators of structural distress. Weight loss and corrosion can pertain to overall maintenance issues without necessarily indicating immediate structural failure. Increased fuel consumption may point to inefficiencies or engine issues, but it does not specifically reflect on the aircraft's structural state. Color change and surface smoothness, while they can suggest cosmetic or material degradation, do not provide the same direct indicators of structural integrity as the signs mentioned in the correct choice.