Which situation could signify a need for manual gear deployment?

The situation that signifies a need for manual gear deployment is when there is a gear warning light failure while other systems are functioning. This indicates that the pilot may not have an accurate read on the landing gear status; therefore, relying on the normal indications can be risky. The failure of the gear warning light suggests that there could be an issue with the landing gear system, and manual deployment is necessary to ensure the gear is down and locked before landing. By manually deploying the gear, the pilot can confirm its status mechanically, providing a safety measure against undetected malfunctions.

In contrast, the presence of a flashing green light on the dashboard usually indicates that the gear is in the process of being extended or retracted, suggesting that no immediate action is necessary. The absence of warning lights and gauges indicating gear status may reflect a lack of faults but doesn't explicitly require manual gear intervention, as normal operation could still be occurring. Delayed landing clearance from air traffic control might create additional stress but does not directly relate to the mechanical status of landing gear.