Why are chocks or blocks crucial in hangar operations?

Chocks or blocks are crucial in hangar operations primarily because they prevent the aircraft from rolling during repairs. This is vital for maintaining safety while performing maintenance tasks. When an aircraft is stationary, especially in a hangar where various maintenance activities occur, it is essential to ensure that it does not move unexpectedly. Using chocks effectively secures the aircraft in place, allowing technicians and maintenance personnel to work confidently without the risk of the aircraft inadvertently rolling away, which could lead to accidents or injuries.

The other options, while they may be related to various aspects of aircraft operations, do not directly address the specific function of chocks or blocks. For example, organizing maintenance schedules is important for operational efficiency, but it is not a role played by chocks. Similarly, assisting in fuel storage and being part of the check-in process are tasks that involve different tools and protocols, unrelated to the primary purpose of chocks. Thus, the correct answer highlights the essential safety function that chocks serve in hangar operations.