What is an "airborne emergency" procedure?

An "airborne emergency" procedure refers specifically to a set of protocols that aircrew utilize when they encounter a system failure or any critical situation while in flight. These procedures are designed to ensure the safety of the aircraft and its occupants by providing clear, definitive steps to take in response to emergencies.

The importance of these procedures lies in their ability to provide immediate guidance and actions that can help mitigate risks and manage potentially dangerous situations. They may include checklists that outline how to handle specific failures, such as engine malfunctions, electrical failures, or cabin depressurization, enabling the crew to swiftly and efficiently address the issue while maintaining control of the aircraft.

In contrast, the other options describe procedures or protocols that are not specific to managing emergencies encountered during flight. The focus of airborne emergency procedures is on in-flight responses, making option C the accurate depiction of what constitutes an "airborne emergency" procedure.