Final answer:
The manufacturer issues maintenance manuals to provide mechanics with information on properly maintaining the aircraft or engine.
Step-by-step explanation:
The manufacturer of an aircraft or engine issues maintenance manuals, also known as Aircraft Maintenance Manuals (AMMs) or Engine Maintenance Manuals (EMMs), to provide mechanics with the necessary information to properly maintain and repair the aircraft or engine.
These manuals include detailed instructions on various aspects of maintenance, such as routine inspections, troubleshooting procedures, component replacement, and service intervals. They also contain technical specifications, diagrams, and charts to assist mechanics in understanding the systems and components of the aircraft or engine.
Additionally, manufacturers may provide service bulletins or letters to address specific maintenance issues, modifications, or updates to improve the performance, reliability, and safety of the aircraft or engine.