If an aircraft operating under FAR part 91 has an inoperative piece of equipment that is not a hazard, what should be done?

When an aircraft operating under FAR Part 91 has an inoperative piece of equipment that is not considered a hazard, the proper procedure is to deactivate the equipment and placard it as "inoperative." This means that the equipment is acknowledged as non-functional, and it needs to be marked clearly to inform any pilot or maintenance personnel of its status. Importantly, under certain conditions, repairs can be deferred indefinitely as long as it does not affect the safety of flight or the operational capabilities of the aircraft.

This approach allows for flexibility in maintenance scheduling while ensuring that safety is maintained. Deactivation and placarding is a standard practice for items that do not impact the aircraft's overall safety or compliance with type certification requirements. It is also crucial that the pilot in command and maintenance personnel are aware of the inoperative status to ensure safe operations.

In contrast, the other options imply immediate action is required, such as repairs before the next flight or within a specific timeframe, which may not be necessary if the equipment is truly non-hazardous. Additionally, the choice of repairing during the next inspection may not be optimal timing depending on the aircraft's operational needs. Therefore, deactivation with a placard provides a suitable balance between compliance and operational flexibility.