What indicates that a missed approach is occurring?

A missed approach is a procedure that pilots follow when they cannot safely land an aircraft, typically due to visibility issues or other factors that compromise the landing approach. Sudden changes in sounds and vibrations can indicate that the aircraft is transitioning from the landing approach to a go-around phase. This could be related to throttle adjustments as the engines increase power to climb away from the runway. Thus, the abrupt changes in sounds associated with engine performance and the corresponding vibrations are clear indicators that a missed approach is occurring.

While visual signals from the cockpit and communication from cabin crew may also provide information, they are not as directly indicative of the action being taken as the immediate sensory changes experienced during a missed approach. A gradual decrease in altitude, on the other hand, would typically relate to a normal descent phase rather than the actions taken during a missed approach.