FAA Powerplant Written Practice Test

What must be done to an aircraft cylinder wall once it is ground to an oversized during overhaul?

1. Replace the cylinder

2. It must be resurfaced or honed

3. Coat with oil

4. Leave it as is

The correct answer is: It must be resurfaced or honed

When an aircraft cylinder wall has been ground to an oversized diameter during an overhaul, it is essential to ensure that the surface is prepared to meet the stringent requirements for performance and longevity. Resurfacing or honing the cylinder wall allows for the removal of any irregularities that may have been introduced during the grinding process. Honing in particular helps to create the proper surface texture that promotes oil retention and helps in the formation of a good seal between the piston rings and the cylinder wall. This surface finish is crucial for minimizing wear, ensuring proper lubrication, and maintaining the overall efficiency of the engine. The honing process also helps to achieve the desired cylinder clearance for optimal piston performance. Simply applying oil would not address the irregularities or surface imperfections left after grinding. Moreover, not addressing the surface preparation could lead to premature wear or failure of the engine components. Therefore, honing the oversized cylinder wall is a necessary step to ensure the cylinder operates efficiently and reliably within its designed parameters.