Which condition would trigger a standard emergency protocol alert?

The condition that would trigger a standard emergency protocol alert is a fire or smoke condition. This scenario represents a serious safety hazard that poses immediate risks to the health and safety of passengers and crew members. When a fire or smoke is detected, it requires rapid response measures to ensure evacuation, fire suppression, and clear communication to emergency services.

Implementing emergency protocols in this situation is critical to prevent potential loss of life or injuries and to effectively manage the emergency. Situations like a delay, heavy passenger loads, or signal color changes do not necessarily warrant an emergency alert; instead, they may require operational adjustments but do not pose the same level of immediate danger.