How are AN-type fluid line fittings identified?

AN-type fluid line fittings are typically identified by their common color coding, which is blue or black. This color coding serves a critical purpose in aviation maintenance and safety, as it helps differentiate between different types of fittings and fluid lines. The blue fittings are generally used for aluminum tubing, while the black fittings are usually associated with steel tubing. This visual identification allows mechanics and technicians to quickly and accurately identify the types of fittings in use, ensuring compatibility and proper installation in fluid systems.

The significance of this color coding cannot be understated, as it reduces the risk of errors in assembly and maintenance, thereby enhancing safety in aircraft operations. Without this system of identification, it would be far more challenging for A&P mechanics to ensure that the correct fittings are used in the correct applications, potentially leading to dangerous situations in flight.