The Reason Planes Dim the Cabin Lights During Takeoff and Landing

Like so many other airplane procedures, dimming the cabin lights during takeoff and landing is primarily done for safety reasons, which a pilot and a flight attendant outline below.

If you think you have a lot to cross off on your pre-vacation to-do list, just imagine how many items are on a pilot’s checklists. Yes, that’s plural. According to Air Canada, even prior to the plane being in the air, pilots have three checklists to cover: “before start,” “after start,” and “before takeoff.” While passengers aren’t privy to most of the items on the lists, we do notice some of them. For example, have you ever wondered why cabin lights are dimmed during takeoff and landing, regardless of the time of day? I have. To be frank, it often annoys me, especially if I’m in the middle of reading a book or in-flight magazine. Well, we asked a couple of experts, and here’s what they have to say about leaving passengers in the dark. Spoiler alert: It’s not just to save on electricity.

According to Agnes Chantre, chief pilot at Air Tahiti Nui, dimming the cabin lights is important because it allows passengers’ eyes to adapt to darkness. “When you want to see the stars at night, your eyes need time to adapt after being inside with a bright, clear light,” Chantre explains to Travel + Leisure. “This procedure is to reduce the time.” Of course, my next question is why do our eyes have to be able to adapt quickly during a flight? The answer to that question is emergency evacuation preparedness, especially in the event of a loss of power.

Paula S. Adams, a flight attendant who used to work for Etihad Airways before going private, tells T+L that dimming the cabin lights is done first and foremost for passenger safety, not passenger comfort. “Takeoff and landing are the most critical phases of flight where the majority of incidents occur,” says Adams. “If an emergency (crash, aborted takeoff, evacuation) happens, passengers and crew need to be able to see outside and adjust quickly.” Indeed, according to the latest data reported by the International Air Transport Association (IATA)—which represents 350 airlines around the world—more than half (53 percent) of airplane accidents occur during landing. After landing, the most dangerous times, statistically speaking, are takeoff, approach, and initial climb. Cruising, when the plane is mid-air, only accounts for 4.6 percent of accidents.

Still, despite the recent crash of Air India Flight 171, airplane accidents are quite rare. Based on the statistics, IATA says you’d have to fly 365 days a year for more than 100,000 years before you’d find yourself in a fatal crash. Meanwhile, data analyzed by the Massachusetts Institute of Technology indicates that approximately only one in every 13.7 million passenger boardings is at risk of being in an accident (and this includes non-fatal incidents). Still, airlines are overly cautious.

Adams says dimming cabin lights during takeoff and landing also reduces interior glare on the windows. “This makes it easier for crew and passengers to spot hazards outside like fire, smoke, debris, etc.”  And when the lights are dimmed, it’s easier to see visual cues inside the aircraft including the emergency floor path markers which are illuminated by photoluminescent strips. Finally, dimming the cabin lights at takeoff and landing does help conserve power, although it’s a minimal amount. “On some types of aircraft, especially older ones, or in certain situations like low power or backup power mode, reducing non-essential loads during takeoff and landing helps prioritize systems that are critical to flight safety,” explains Adams.