Which practice helps control corrosion in aircraft fuel systems?

• A. Water separation and moisture control.
• B. Hydrogen embrittlement prevention.
• C. Increasing fuel temperature.
• D. Seal joints with silicone.

Answer: (A)

Water in fuel is the main driver of corrosion in aircraft fuel systems. When moisture is present, it forms an electrolyte that accelerates corrosion of metal parts, especially in tanks, pumps, and lines, and it can also promote microbial growth that compounds corrosion problems. Keeping fuel as dry as possible—through water separation and moisture control—removes the source of this electrolyte, reducing rusting and pitting and protecting system components.

Hydrogen embrittlement prevention focuses on preventing cracks in some high-strength metals under certain conditions, which isn’t the primary corrosion issue in typical fuel systems. Increasing fuel temperature can actually worsen corrosion rates or promote water separation, rather than prevent corrosion. Sealing joints with silicone might help with leaks but isn’t a corrosion control practice for the fuel system and can introduce contaminants.

So, removing water and controlling moisture directly addresses the environment that drives corrosion in the fuel system, making it the most effective approach.