fray bentos pielot

My apologies for a rather trivial post here but this has been bugging me for a while now.

I have often wondered why interior cabin lights are dimmed or even turned off when landing at night?

Cheers…

apaddyinuk

Its generally only done in the hours of darkness and its basically to ensure that your eyes are prepared should the aircraft suddenly crashes and you need to get out in complete darkness!!!! But we obviously dont say that in the PA's!!!

broadreach

Fray Bentos,
To better accustom your eyes to a total blackout in the event of an accident/incident when all electrical power is shut off and when you might need them to find your way out.
"Fray Bentos", hmm, haven't heard that in a long time. Anglo?
Saludos

blueloo

IMHO that line of reasoning is a bit "rubbishy". In the few minutes the lights are turned off prior to departure it doesnt give much time for your eyes to adjust at all, especially when half the cabin then turns their reading lights on!


(It doesnt do you much good when the planes a flaming inferno anyway!)


The main reason given by US airlines, is to improve the view on departure for pax......(sounds like rubbish to me as well)


The reason some carriers leave their internal lights on and window shades up on departure at night is to improve aircraft visibility. It is amazing what a difference it makes. Taxiing out of Narita recently, which is a mass of lighs anyway, we could hardly see the Jumbos from various American carriers (presume it would be the same for other airlines without lights on, just only happened to see American Carriers taxiing), yet when another airline with its internal lights on taxied past, it was like a row of strip lighting down the side. Without the lights you just see, Stobes and beacons and nose taxi lights, there is no depth or size perception of the aircraft.....


Anyway, each to their own eh.

Approaching Minimums

This is exactly the same reason why I haven't ever understod why many American carriers have uninstalled their logo lights or they don't use those at all if they are fitted. Even logo lights aren't mandatory it is much easier to reconize the aircraft on the ground if they use those lights. I know they use reduced maintenance costs as an excuse but that sounds very ridiculous for me...

What comes to dimming of cabin lights, I guess it is done because of the safety and give better view for the passengers. Approaching big city at night is very spectacular sight if cabin lights are dimmed... Anyone who has flown to Mexico City at night definitely knows what I'm talking about!

Isn't cabin lights also dimmed/turned off to reduce possible fire risk from broken lamps in case of emergency landing?

Best Regards,
Approaching Minimums

Pilot Pete

My company, with a fleet of 32 Boeings, did a study last year and found that we spent circa GB£140,000 on Logo Light bulbs.

I can quite understand why an airline wants to get rid of a non-mandatory item like this. We have no order to not use them, it is left to the pilots' discretion, but more and more pilots are only turning them on when on the ground at night, or below 10,000' on approach....and before you ask, apparently it's the duration that they are on for that leads to failure, not the heat/ cool cycle of switching them on/off...

PP

domonion

As far as I'm aware, I've always been told it's one of two things. Definitely to make pax eyes adjust to the dark and also the fact that the pax are our eyes and ears. There are more pax than cabin crew and in the likely hood of and emergency, if the lights are off they can see what's going on outside and let us know.

tom24

Amazing.........

Just two months ago my ATPL A.G.K. tutor was telling the class the reason for doing so is to increase the electrical power available during T/O and landing, or something along those lines!!!!

Approaching Minimums

Pilot Pete wrote:

I'm not surprised of that... In commercial aviation everything seems to be VERY expensive no matter if it is just a light bulb or small drink table of the seat (10x10 cm piece of plastic á la 150 euros each!)

However, when you are thinking of pure maintenance cost of logo lights then you should also think about of the marketing value of those lights as they make your airline and brand more famous at the airport and it's surroundings.

Best Regards,
Approaching Minimums

Boss Raptor

Covered several times earlier, see;

http://www.pprune.org/forums/showthr...t=cabin+lights

Logo lights are not actually a standard fit on aircraft, they are a customer option (cost extra!) and are also relatively easy to retrofit and/or remove...and as staed above like most things in aviation they are not cheap

sixmilehighclub

You're all wrong!

The lights are dimmed to give the cabin crew the chance for a quick nap out of the eyes of the passengers.

zzzzzzZZZZZZZZZZZZZ

TightSlot

My understanding is as follows:

• Permits passenger (and crew) eyes to develop some degree of night vision - useful for spotting events outside the aircraft and also as a prep in case of evac
• In an evac, some people may be reluctant to leave a brightly lit interior for a dark exterior.
• Reduces chance for dazzle if Flight Deck door comes open or is opened during take off roll
• Reduces live electical items on take-off (means of ignition)

Some of these items may be more valid than others, in the opinion of some people: These would presumably be the same people that bypass the process by switching on their reading light. BTW, the practise is route and passenger profile specific. On some routes, without fail, dimming the lights is the signal for almost all passengers to immediately reach for the reading light button: On others, those with reading lights already on will switch them off.

As with so many things in aviation, this seems such a minor imposition for a good reason, but one which is of epic inconveniece to many - C'est la vie!

PAXboy

When Logo Lights were introduced, I thought it one of the cleverest bits of marketing of all time. Yes, it may cost money but it is marketing that you can directly control.

I guess the cost is that the lamps are cold when they are turned on and generate a lot of heat and so burn out quicker. Once they move on to LED clusters, that might change.

--------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.

Trislander

tom24,

Tell your mate he's wrong! Why would you need extra electrical power for t/o? you need max EPR at t/o hence the need to switch off compressor bleed air systems, such as anti-ice (most of the time!), Air conditioning, etc. The APU provides electrical pwr until it is shut down shortly after departure.

Tightslot has the actual reasons correct.

Also- leaving the window blinds open for t/o so that a/c is easier to be seen? -Bol**cks! Maybe worth a try if you have a complete strobe & nav light failure perhaps?! It's done so that pax can alert the crew if they see fire, not mandatory, but some airlines have adopted this procedure since the Kegworth disaster.

Tri

Piltdown Man

It is so that it's easier to evacuate at night. The non-runners in ths thread are: Electrical power consumption (even with the tosh about the APU), Better view for PAX, Broken lamps (we'd turn those off during the day then, wouldn't we?).

Pilot Pete

Sorry about the thread creep back to logo lights, but just a quick reply to the comments about marketing. Sure, on final approach or T/O close in to the airfield, punters on the ground can see your tail/ logo. On the ramp at the majority of airports that I visit (both UK and abroad), the ramp is so well lit you can see the whole aircraft and all it's paint scheme without the logo light on..... another way of saving bulb life and hence costs.....

PP

fescalised portion

The company that I work for does not dim the cabin lights for Take-off or Landing.

With regard to Logo lights, they have also deactivated them all on the whole fleet due to associated maintainence costs of circa $1m per year!! They do have a large fleet though....