What is a hangar used for in aviation?

A hangar is specifically designed for the maintenance, repair, and storage of aircraft. Aircraft maintenance is a critical function that takes place in a hangar, where technicians can work on planes in a controlled environment, shielded from the elements. This ensures that all safety checks and necessary repairs can be conducted efficiently and effectively, allowing for proper upkeep and compliance with aviation regulations.

The other options relate to different aspects of aviation but do not accurately define the primary use of a hangar. Passenger luggage is typically stored in designated luggage areas at airports, flight attendants are trained in specific facilities designed for crew training, and while hangars can provide services related to aircraft landings, they do not serve the function of landing aircraft themselves. Thus, the correct answer clearly emphasizes the maintenance role of hangars in aviation operations.