What is a common effect of corrosion on aircraft structures?

Corrosion on aircraft structures typically results in the weakening of metal surfaces. This phenomenon occurs when metal interacts with moisture and other environmental factors, leading to deterioration of the material's integrity. Over time, corrosion can create pits, cracks, and other forms of damage that reduce the structural strength of components. This weakening can compromise the safety and performance of the aircraft, making it vital for maintenance personnel to regularly inspect and treat any signs of corrosion to ensure the aircraft remains airworthy.

The other options do not accurately describe effects of corrosion: Improved fuel efficiency is not a consequence of corrosion; airflow could be negatively impacted due to rough or pitted surfaces from corrosion; and rather than reducing weight, corrosion typically necessitates repairs or replacements of structural components, which can actually add weight if not managed properly.