cabin lights dimmed
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From my vague memory, there are many suggestions..
Less electrical source to start a fire in an emergency landing.
Allowing your eyes to be adjusted to night vision in the event of an emergency evacuation.
I'm sure there were other reasons also.
From my vague memory, there are many suggestions..
Less electrical source to start a fire in an emergency landing.
Allowing your eyes to be adjusted to night vision in the event of an emergency evacuation.
I'm sure there were other reasons also.
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rm is right. The main reason is so that your eyes get adjusted to the natural light so if the emergency lights do come on, they will stand out a lot more.
My current arline only requires the lights to be dimmed during the hours of darkness, but at my last compay, it was a requirement for ALL take offs and landings, which I think is better. But that is my only personal opinion!
I can see your point about the reading lights though, although the cabin is still much darker than normal.
My current arline only requires the lights to be dimmed during the hours of darkness, but at my last compay, it was a requirement for ALL take offs and landings, which I think is better. But that is my only personal opinion!
I can see your point about the reading lights though, although the cabin is still much darker than normal.
I suspect there is a certain amount of myth here. Lights being dimmed for night take off and landing in passenger aircraft was ostensibly for better night vision. Practically speaking it is and was a waste of time. You need several minutes of total darkness to gain an appreciable benefit. Typically there is a fair percentage of passengers who will have their over head reading light on and believe me that is a very bright light that effects nearby passengers night vision. The pilots of course will have landing lights on plus map lights and of course bright approach and runway lights. So you can effectively scratch their night vision.
The flight attendants will be strolling down the aisles also being effected by reading lights and certainly there will be some lights in the galley. When the cabin lights are dimmed, it effectively makes it difficult for elderly passengers and those wearing glasses, to pin point the emergency exit signs even if they can see over the passengers seat directly in front of them. Of course, if you then decided to look at the safety briefing card in your seat pocket shortly before landing or take off to familiarise yourself with the position of the emergency exits or to read how to open the main doors, you will probably need to turn on the over head reading light - so, scrub night vision again. If the airlines were really serious about night adapation then as well as all ceiling lights, all overhead reading lights should be switched off well before take off and landing. If it is good enough that seat backs should be raised and seat belts secured for every single person on the aircraft, then all overhead reading lights (being the brightest of them all) should also be turned off. I can just imagine any airline insisting on that! Which brings me back to the thought that dimming of ceiling lights is paying lip service to an emergency.
If the aircraft aborts the take off at high speed and that takes anything up to 45 seconds of screeching brakes, reverse thrust and other horrible noises, then I am sure most passengers, especially the elderly and sight impaired (wearing glasses, stupid!) would prefer to be able to see immediately the position of the exit signs. But with the cabin lights romantically dimmed (for your comfort and safety?) these signs are hard to focus on with all the vibration and racket and fear in an abort.
So, if the reason for dimming the cabin lights is for passenger night adaption, then forget it because half the passengers and all the flight attendants and all the flight crew will be out of the picture.
I have been in one airliner where the flight attendants actually turned off all the ceiling lights for take off and landing in the middle of a bright sunny day for night vision adaption...
The flight attendants will be strolling down the aisles also being effected by reading lights and certainly there will be some lights in the galley. When the cabin lights are dimmed, it effectively makes it difficult for elderly passengers and those wearing glasses, to pin point the emergency exit signs even if they can see over the passengers seat directly in front of them. Of course, if you then decided to look at the safety briefing card in your seat pocket shortly before landing or take off to familiarise yourself with the position of the emergency exits or to read how to open the main doors, you will probably need to turn on the over head reading light - so, scrub night vision again. If the airlines were really serious about night adapation then as well as all ceiling lights, all overhead reading lights should be switched off well before take off and landing. If it is good enough that seat backs should be raised and seat belts secured for every single person on the aircraft, then all overhead reading lights (being the brightest of them all) should also be turned off. I can just imagine any airline insisting on that! Which brings me back to the thought that dimming of ceiling lights is paying lip service to an emergency.
If the aircraft aborts the take off at high speed and that takes anything up to 45 seconds of screeching brakes, reverse thrust and other horrible noises, then I am sure most passengers, especially the elderly and sight impaired (wearing glasses, stupid!) would prefer to be able to see immediately the position of the exit signs. But with the cabin lights romantically dimmed (for your comfort and safety?) these signs are hard to focus on with all the vibration and racket and fear in an abort.
So, if the reason for dimming the cabin lights is for passenger night adaption, then forget it because half the passengers and all the flight attendants and all the flight crew will be out of the picture.
I have been in one airliner where the flight attendants actually turned off all the ceiling lights for take off and landing in the middle of a bright sunny day for night vision adaption...
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Yes but no but, that doesn't answer the question of why are the cabin lights dimmed for take-off? The guy next to you doesn't have to spoil your night vision if he puts his reading light on because you can turn it off for him, and he will thank you!
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Is there a clue in that it has been pointed out in this thread that it doesn't matter if the cabin lights are dimmed or not, the pilots are still going to be blinded by their landing lights and can't see a thing anyway! So there's no point, OK yar?
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Sounds good enough for me. Stop questioning it everybody! Henceforth, any one who questions it is fair game for getting chewed up, OK?
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Previous comments noted, but it's my observation that even with a significant number of passengers with their reading lights ON, the overall light in the cabin is MUCH less when the main cabin lighting is turned OFF.
It's nothing to do with adaption to night vision, it's all about light gradient, that is, vision from light to dark (as during an evacuation) is much improved as the light at the viewer's end is decreased, whether they be night adapted or not. Ascertaining the safest escape route is the reason.
It's for similar reasons that the window shades must be UP for Takeoff and Landing.
Regards,
Old Smokey
It's nothing to do with adaption to night vision, it's all about light gradient, that is, vision from light to dark (as during an evacuation) is much improved as the light at the viewer's end is decreased, whether they be night adapted or not. Ascertaining the safest escape route is the reason.
It's for similar reasons that the window shades must be UP for Takeoff and Landing.
Regards,
Old Smokey
The window blind thing is supposed to be over the wing exits only - the theory being you wouldn't or shouldn't open the emergency exit into the flames. But the flames outside will really stuff your little old ladies night vision anyway - or light and darkness gradient (whatever). How long does it take to lift a window blind? Two seconds, maybe? So why do the airlines persist in propogating myths and pulling up the window shades at top of descent in preparation for the mythical crash on landing in flames. If they are that worried about a crash then why not go the whole hog and instruct passengers to take up the brace position for every landing. Just in case, you know.
