Before performing maintenance on an aircraft, which of the following is a primary precaution?

Prior to conducting maintenance on an aircraft, it is crucial to take comprehensive precautions to ensure safety and efficiency. One of the primary precautions is to secure the aircraft against movement. This involves implementing measures such as using wheel chocks and ensuring the brakes are applied, which prevents any accidental rolling or shifting of the aircraft while maintenance is being performed.

Additionally, notifying all ground crew is vital for maintaining awareness of ongoing tasks and ensuring that everyone is informed of the maintenance work, which helps prevent accidents and miscommunications. Clearing the area of tools and other potential hazards is also important as it minimizes risks of tripping or tool-related accidents during maintenance procedures.

Choosing all of the above as the answer reflects an understanding that comprehensive safety measures encompass multiple aspects, making it a sound approach to ensuring the working environment is safe and controlled during maintenance activities. This holistic precautionary approach is essential for effective maintenance operations and overall safety.