Which indicator shows a slow approach speed?

The upper green chevron is the indicator that signifies a slow approach speed. In aviation instruments, particularly on speed indicators, the colors and shapes are designed to convey specific information about the aircraft's performance and operational limits.

The upper green chevron typically represents a safe or optimal speed range for landing configuration. When the aircraft approaches this speed, pilots are assured they are within the appropriate parameters for a safe landing. This visual cue helps prevent exceeding the airspeed limits for landing, which is crucial for the aircraft's safety and handling characteristics during critical phases of flight.

In contrast, the other indicators represent different parameters or conditions. For instance, the upper red triangle commonly denotes an overspeed condition, the lower blue diamond might indicate a different speed limit (such as a stall warning), and the middle yellow square tends to represent cautionary thresholds that pilots should be aware of but do not denote the optimal or safe landing speed. Understanding these indicators is essential for effective flight management and safety.