AMP - Aviation Maintenance Technician Powerplant Practice Exam

What is magnetic particle inspection (MPI)?

1. A testing method for assessing electrical systems in aircraft

2. A non-destructive testing method for detecting defects in ferromagnetic materials

3. A visual inspection technique for engine components

4. A process for analyzing the chemical composition of materials

The correct answer is: A non-destructive testing method for detecting defects in ferromagnetic materials

Magnetic particle inspection (MPI) is a non-destructive testing method specifically designed to detect surface and slightly subsurface defects in ferromagnetic materials. The process involves using magnetic fields and finely ferromagnetic particles, which can be either dry or suspended in a liquid, to reveal defects such as cracks, laps, and voids. When an object is magnetized, any defects in the material will disrupt the magnetic field. The ferromagnetic particles gather at these disruptions, making the defects visible under appropriate lighting conditions. This method is particularly effective for inspecting components made from iron, nickel, and cobalt, which are commonly used in aviation components due to their strength and magnetic properties. Understanding the specific function of MPI is key, as it is widely used in the aviation industry for safety and maintenance purposes. The other options provided do not accurately describe MPI, as they pertain to other inspection methods or processes that serve different purposes in aircraft maintenance and testing.