How long does it take for a slide to inflate completely?

The correct duration for a slide to inflate completely is 4 to 9 seconds. This timeframe is critical for ensuring the safety of passengers during an evacuation. The quick inflation of the slide allows for rapid egress from the aircraft, which is vital in emergency situations where every second counts. The design and functionality of inflatable slides are engineered for swift deployment to ensure effective and timely use.

Other durations listed do not align with the typical operational standards observed in aviation safety protocols. For instance, inflation taking 2 to 4 seconds may be too quick, considering that slides need an adequate amount of time to fully expand and stabilize. Conversely, inflation times of 10 to 15 seconds or longer could compromise an effective evacuation in urgent scenarios. Hence, the 4 to 9 second timeframe strikes an optimal balance for safety and efficiency.