cabin lights dimmed
 

something i've always wondered! why are the cabin lights dimmed for landing???!!! tanx

its so that passengers' night vision (tranfer of light sensing from rods to cones on the retina) can adapt before touchdown,so that if you have a less than perfect landing,and require evacuation into the dark night,your eyes will not be shocked to be outside since the cabin was already dark,allowing them to be pre-adapted.

Not sure this is an agony aunt question though...
;)

Thats the answer I'd have given too.

But what worries me is that when the cabin lights are dimmed 50% of the passengers put on their reading lights, which surely defeats the object.

Wouldn't it be better to disable the reading lights for landing at the same time?

Why would it be dark upon a crash landing? I would have thought the resulting explosion and fire would light up the entire countryside!!!!

If evacuation after landing is required. The engines will be shut down prior to the evacuation starting. Once the engines have been shut down and the APU is not running to provide electrical power, the cabin will be plunged into dakness. The emgency lighting system will then be activated which will guide you to your escape route.

In that case, there wouldn't be any point worrying about people's night vision!

ei-bos: if you want to read more about it, use 'Search' for 'Dimming'

An interesting one. As one contributor has pointed out, the glare from overhead reading lights would put pay to any preservation of night vision a pax might have. I have never seen any written (CAA or otherwise) regulation requiring the dimming of lights - perhaps another of life's mysteries and here's another one: why do you have to tie the life-jacket tapes in a double bow on the LEFT. WHy the left?

Judge - the use of reading lights only still leaves the cabin much darker than full lighting. QED

I know the 'doublebow on the left' is certainly the BA brief, and it was done to enable sufficient 'spare' tape to allow survivors to be tied to whatever if appropriate - symmetrical tying does not leave enough spare. I don't know if any other airlines use it. It may appear 'comical' but there might be times when it would be a good idea?

I was told in my wet drills that the bow on the left was because the toggle was on the right. So if they were both on the same side there is a chance that when you go to inflate it, that you undo the tape instead of firing the the co2 in the heat of the moment. And the tape length is desined for this.

NOw the next thing that i have thought about is that if the person requires a seat belt extension. Is there enough tape to go twice round?


MJ

Why do pilots say

"We are now making our final approach"?

Did they make other approaches that they didn't tell you about?

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What does it mean to 'pre-board'? Do you get on before you get on?

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How come when you stand in the middle of a library and go 'aaaaggh' everyone just stares at you? But if you do the same thing on an aeroplane, everyone joins in?

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Lights on takeoff/landing query
 

Can anyone tell me why cabin lights are dimmed for takeoff/landing in the hours of darkness?

i) in case of evacuation - pax night vision when proceeding outside the aircraft is improved.

ii) if flight deck door is opened inadvertently, forward (night) vision of flight crew is preserved.

Why are the 'flaps' on the windows INSIDE the aircraft open on take off and landing?
All cabin crew say they have to be open for take off and landing.

So you can see the flames and run the other way?:D

PS They are called 'window blinds'. The flaps are on the wing.

Why is it that when you arrive at the airport you see the words "Terminal"!!!!!!!!!!

stressedman
 

its because after reading all these stupid questions you feel like shooting yourself, aaaaarrrrrrrrrgggggggg:mad:

Question
 

Why, on a night landing, do the cabin lights get dimmed?

So that the cabin crew or other surviving passengers, may see more clearly the safest escape route,after a landing accident requiring evacuation.

Vision is much better from dark to light, than light to dark.:cool:

Regards,

Old Smokey

cabin lights dimmed
 

what i always wanted to know: why are cabin lihts dimmed/turned off during t/o and ldg. i was naive enough to think it is done to make the pax have a nicer view at night but recently cabin crew said they dimm the lights according to some regulations. so it seems to be compulsory.
any help? thanx in advance

Use the search function and you'll find the topic dealt with in depth previously.

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.

thanx rm,
found some reasons, but all seems not very convincing regarding the fact that many people switch on their reading lights ....

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.

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...

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!

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?

Sounds good enough for me. Stop questioning it everybody! Henceforth, any one who questions it is fair game for getting chewed up, OK?

Does anyone know why the lights in the cabin are dimmed on take off and landing.

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

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.