During the 100-hour inspection, what should be checked regarding the push-pull tube-type control system?

During a 100-hour inspection, it is essential to verify the amount of thread engagement of the threaded rod ends in a push-pull tube-type control system. This check ensures that the rod ends are properly secured, which is crucial for maintaining control surface integrity and safety. Inadequate thread engagement can lead to looseness or failure of the control system, potentially resulting in a loss of control during flight.

While other factors such as fluid levels and wear on push-pull tubes may also be significant considerations during maintenance, the specific requirement to examine thread engagement directly pertains to the operational reliability of the control system. Ensuring that the threads are engaged correctly prevents issues that could arise from slack or inadequate fastening in the assembly, thereby directly contributing to the safety and performance of the aircraft.