Cabin lights out before takeoff

Oriel

Why do the pilots turn the cabin lights off before take off?
The only reason I can think of would be for visibility reasons, in case something went wrong during takeoff.
But once you've left the ground, surely that wouldn't matter?

electric69

To provide max power for takeoff.

FlutterinBantam

The correct reason is that so the passengers eyes can get used to the current lighting conditions outside and in the event of a problem will take less time to adjust if an evacuation is neccessary.

*Kol*

electric69 wrote: »

To provide max power for takeoff.

??????????:rolleyes:

electric69

FlutterinBantam wrote: »

The correct reason is that so the passengers eyes can get used to the current lighting conditions outside and in the event of a problem will take less time to adjust if an evacuation is neccessary.

Where did you get that information??

Mint Sauce

FlutterinBantam wrote: »

The correct reason is that so the passengers eyes can get used to the current lighting conditions outside and in the event of a problem will take less time to adjust if an evacuation is neccessary.

probably similar reason for keeping the blinds up, so the emergancy services can see you if the plane goes down

Gordon

FlutterinBantam wrote: »

The correct reason is that so the passengers eyes can get used to the current lighting conditions outside and in the event of a problem will take less time to adjust if an evacuation is neccessary.

Did anyone see the Mythbusters episode on pirates? They did a myth that was concerning a pirate's eyepatch. Some have said that the true reason for a pirate wearing a patch was so that he could swap the patch over when taking over a ship - due to the need for a quick eye adjustment to the dark. It turns out that wearing a patch and swapping it over when in dark places really does give you a form of night vision.

Oriel

Any serious answers, apart from FlutterinBantam?

kraggy

FB is right.

http://www.pprune.org/forums/archive/index.php/t-278685.html

Foggy43

Yes! FB is correct.

Your eyesight will be adjusted to the no lighting condition in the cabin in the case of an emergency evacuation.

I have been on an EI flight or two where the Cabin Crew have forgotten to switch the lights off.

If you cannot turn the cabin Lights off on an aircraft it is 'No Go'. A safety issue for take off and landing.

RoundyMooney

Indeed.

Aside from the thread reference, CC have mentioned it on a couple of occasions during the safety announcements, in my experience.

Oh, and electric69, quit trolling other members of the forum, because they've given a correct answer, rather than an uninformed bluff.

pclancy

You'll also notice if you've been as bored as I have on Airbus planes the emergency exit signs are lit and easy to see when the planes on the ground and with the main cabin lights dimmed then a "bing" sound once the plane has climbed to a certain altitude they go off and the cabin crew leave their exit stations, i presume its automatic when the wheels go up or somethin?

*Kol*

pclancy wrote: »

You'll also notice if you've been as bored as I have on Airbus planes the emergency exit signs are lit and easy to see when the planes on the ground and with the main cabin lights dimmed then a "bing" sound once the plane has climbed to a certain altitude they go off and the cabin crew leave their exit stations, i presume its automatic when the wheels go up or somethin?

I think if you look at those EXIT signs they are photo luminescent so they will always be easier to see in darker conditions (they are always "on" but wont appear to be as bright in bright conditions).

Normally the "bing" is accompanied by the fasten seat belt light going on or off. This is normally switched off by the captain when the aircraft is in cruise. Gear up would be a bit early as the gear is selected up just after the aircraft lifts off.

brettmirl

I'm pretty sure a flight attendant said she was switching off the cabin lights to minimise light pollution on a flight I was on before.

Can't imagine much light gets out the small windows though.

Mint Sauce

mick_irl wrote: »

I'm pretty sure a flight attendant said she was switching off the cabin lights to minimise light pollution on a flight I was on before.

Can't imagine much light gets out the small windows though.

think thats more of a passenger comfort thing, especilly on evening or night flights

Kevster

The emergency lighting on the floor stays on though. When you then consider that take-off is the most dangerous part of the flight, you can understand why they would want the emergency floor lighting on during this period.

highlydebased

Some airlines dont seem to do it......easyjet notably dont, the majority of EZY flights I have seen takeoff ahead of my own at night have cabin lights on during the takeoff roll. All irish airlines do it. maybe its a case of IAA requirement

Oriel

Thanks folks! I thought it seemed an extreme step to take for the sake of a rare occurance.
I initially thought it was to help the pilot's view of the outside of the plane during takoff, but there you go!

Oriel

Kevster wrote: »

When you then consider that take-off is the most dangerous part of the flight

I thought landing is most the dangerous part of the flight?

deRanged

Oriel wrote: »

I thought landing is most the dangerous part of the flight?

You'd have considerably more fuel to worry about on take off.

jmayo

RoundyMooney wrote: »

Indeed.

Aside from the thread reference, CC have mentioned it on a couple of occasions during the safety announcements, in my experience.

Oh, and electric69, quit trolling other members of the forum, because they've given a correct answer, rather than an uninformed bluff.

It is on pilots checklist and is supposedly for safety reasons.

Actually electric69's answer is related more to other electrical systems such as air con AFAIK so maybe not that much uninformed bluff.
AFAIK air con used to be turned off on older Boeing 737 aircraft during takeoff.
It is definetly off during engine startup.

*Kol*

jmayo wrote: »

It is on pilots checklist and is supposedly for safety reasons.

Actually electric69's answer is related more to other electrical systems such as air con AFAIK so maybe not that much uninformed bluff.
AFAIK air con used to be turned off on older Boeing 737 aircraft during takeoff.
It is definetly off during engine startup.

Air con is not an electrical system. It's driven by air (I'm not being funny). The reason the air con is off during engine start is to allow the APU to give maximum airflow to the engines for starting. Especially necessary for triple spool engines like RB211's.

jmayo

*Kol* wrote: »

Air con is not an electrical system. It's driven by air (I'm not being funny). The reason the air con is off during engine start is to allow the APU to give maximum airflow to the engines for starting. Especially necessary for triple spool engines like RB211's.

Sorry isn't the aircon run from engine power and thus needs to be off during engine startup so that they can spin up?
Does the aircon run off battery if engine off ?
I am also trying to remember the startup sequence on 737 is and if the air con needs to be off during takeoff depending on pressue altitude?

FlutterinBantam

Air con "packs off", yes, was a recognised way of boosting power.

cabin lights are a different story.

Foggy43

The APU provides the air to run the air conditioning packs while on the ground and start engines. There are ground carts that also can provide air to run these packs and start engines in the event of APU failure. The APU also provides electrical power to the aircraft.

When the engines are running they take over running the air conditioning and pressurize the aircraft. Selected by the pilots or flight engineer. The APU is only used in flight in the event of an engine failure. It is used as an electrical backup. A must have on ETOPs aircraft.

The APU is another gas turbine engine but it is started by the aircraft battery.

The Boeing 707 and DC8 did not have an APU. Ground Carts supplied everything until engines started.

*Kol*

jmayo wrote: »

Sorry isn't the aircon run from engine power and thus needs to be off during engine startup so that they can spin up?
Does the aircon run off battery if engine off ?
I am also trying to remember the startup sequence on 737 is and if the air con needs to be off during takeoff depending on pressue altitude?

The aircon only runs from air bled from the engine or apu. On the B787 they will be run by electric motors as the engines will be bleedless.

The aircon will always be on after the engines are running as the cabin preesure controller starts to pre-pressurise the cabin prior to the aircraft leaving the ground on the take off roll.