FAA AMT (Aviation Maintenance Technician) Airframe Practice Exam

The amount of water allowed in a US gallon of turbine fuel is 0.0015%, or 15 parts per million (ppm). This is the maximum water content for turbine fuel to prevent engine malfunction and ensure safe operation. Options A, B, and D are incorrect because they represent higher amounts of water content, which could cause issues with the fuel's ability to properly combust and could damage the engine. Therefore, option C is the only correct answer as it aligns with industry standards and regulations.