Which standard specifically addresses aircraft hangars?

The correct choice, which addresses aircraft hangars, is indeed NFPA 409. This standard outlines the requirements for the design, construction, protection, and maintenance of aircraft hangars, including considerations for fire safety and the protection of property and occupants within those facilities.

Understanding NFPA 409 is crucial for anyone involved in the planning or operation of hangar facilities, as it provides specific guidelines on the materials to be used, fire protection systems to be implemented, and spacing requirements necessary to minimize fire hazards associated with aircraft and flammable materials stored in hangars.

Other standards mentioned may cover different aspects of fire safety or address various industries but do not specifically focus on aircraft hangars in the way NFPA 409 does. This specificity is what makes NFPA 409 fundamental for hangar safety.