FAA Powerplant Written Practice Test

What must be done to an aircraft cylinder wall that has been ground to an oversized during overhaul?

1. It should be completely replaced

2. It must be resurfaced or honed

3. It requires no further action

4. It should be polished with fine sandpaper

The correct answer is: It must be resurfaced or honed

When an aircraft cylinder wall has been ground to an oversized dimension during an overhaul, it is essential to perform additional machining processes to ensure proper function and reliability. Resurfacing or honing the cylinder wall is crucial in achieving the right surface finish and dimensions. Honing involves removing a small amount of material to create a smooth, even surface with specific surface roughness and texture. This is necessary for proper piston seal and lubrication, which are critical for the optimal performance of the engine. A honed surface can also improve the wear characteristics of the cylinder wall, extending its lifespan and efficiency. Resurfacing, on the other hand, ensures that any irregularities from the grinding process are corrected and that the cylinder maintains its structural integrity. The combination of these processes prepares the cylinder wall adequately for installation of the piston and the rings, ensuring that they perform effectively. While there may be other options mentioned, they do not fulfill the requirements for preparing a cylinder wall that has undergone grinding to oversized.