Why Are Window Shades Raised for Takeoff and Landing?

Have you ever wondered why, before takeoff or landing, flight attendants ask you to open your window shade? It might seem like a trivial task, but it actually serves vital safety and physiological functions, particularly during these critical phases of flight. Let's dive into the rationale behind this procedure and explore insights from international organizations such as ICAO and the FAA.

Visibility in Emergencies

The primary reason for raising window shades is to prepare for potential emergencies. Takeoff and landing are considered the most critical phases of flight, as they are the times when incidents like aborted takeoffs, rough landings, or runway excursions are most likely to occur. According to ICAO guidelines, ensuring external visibility during these phases is a crucial part of safety preparation, allowing both cabin crew and passengers to assess the outside environment if an emergency evacuation is needed [Skybrary on Safety Considerations].

In the event of an emergency, the ability to see outside the aircraft helps flight attendants evaluate external conditions such as fire, debris, or blocked exits. This information is vital for deciding the safest evacuation routes and guiding passengers to exits that are not obstructed by hazards. For instance, attendants can instruct passengers to avoid exits facing fire or debris, ensuring a more organized and efficient evacuation.

Light and Dark Adaptation (Cones and Rods)

From a physiological perspective, having window shades open helps passengers' eyes adjust to the changing lighting conditions outside. The human eye adapts to light and darkness gradually. It takes about 10 seconds to adjust to bright light, but full adaptation to darkness can take up to 30 minutes. By opening the shades, airlines facilitate the process of eye adjustment to natural light, which is especially important during nighttime landings. In an emergency, it’s crucial that passengers can see clearly to move quickly and avoid potential hazards.

The key players in light adaptation are two types of photoreceptor cells in the retina: cones and rods.

-              Cones are responsible for color vision and sharp central vision in bright light. They work best in daylight and help us see fine details and distinguish colors. The human eye contains about 6 million cones, and they are concentrated in the fovea, the center of the retina [National Center for Biotechnology Information on Cones]

-              Rods, on the other hand, are responsible for vision in low light. They are more sensitive to light but cannot detect color, meaning they only see in black, white, and shades of gray. Rods are found mainly in the peripheral regions of the retina and are essential for night vision and detecting movement in low-light conditions. There are approximately 120 million rods in the human eye [NCBI on Rods]

As light levels decrease, the eye shifts from cone-based vision to rod-based vision. This transition can take time, which is why it’s important to allow for sufficient light exposure to help your eyes adjust, especially before night flights or landings.

When the shades are raised, the exposure to outdoor light helps your eyes make this adjustment gradually, ensuring that you can move confidently if an emergency occurs.

Regulatory Perspectives: ICAO and FAA

ICAO Recommendations: The International Civil Aviation Organization (ICAO) recommends raising window shades during takeoff and landing as part of standard safety practices. Although this recommendation is not universally mandated, ICAO emphasizes that open shades contribute to heightened situational awareness. Open window shades enable passengers to detect any unusual conditions, enhancing their overall readiness for emergencies [ICAO Safety Procedures].

FAA Guidelines: In the United States, the Federal Aviation Administration (FAA) does not have a specific rule that requires window shades to be opened, but it strongly supports this practice as part of best safety practices. This procedure is widely followed by U.S. airlines as a way to promote passenger awareness during critical phases of flight, aligning with the ICAO's emphasis on safety preparedness [FAA Safety Guidelines]

Light Adaptation and Good Airmanship

Pilots and flight crews are also mindful of light adaptation and its impact on safety. Good airmanship encourages pilots to adjust cockpit lighting when nearing potentially hazardous weather, such as thunderstorms. Dimming cockpit lights during such conditions helps pilots maintain their night vision, ensuring they can operate the aircraft safely and respond effectively in low-light scenarios. This proactive management of lighting is another example of how aviation protocols consider human physiology to enhance flight safety [FAA Airmen's Manual].

Why 30 Minutes?

You may have noticed that the request to open window shades is typically made about 30 minutes before landing. This timing allows passengers' eyes to fully adapt to the light outside, particularly when transitioning from artificial cabin lighting to the ambient natural light. Why Are Window Shades Raised for Takeoff and Landing?. Cones, responsible for color vision, adjust in about 7 minutes, while rods, which help with night vision, take approximately 30 minutes. This preparation window is ideal to ensure that passengers’ eyes are sufficiently adjusted for safe movement in case of an emergency.

In Summary

Raising window shades is a simple yet crucial safety measure that integrates human physiological responses with emergency preparedness protocols. Although not universally mandated, this practice is strongly encouraged by ICAO and widely implemented by airlines worldwide as a best practice to enhance safety. By understanding its significance, passengers can appreciate how such small details contribute to a safer flying experience.