Why flight attendants dim the lights for take-off and landing

[ezzra]

"Dimming the lights allows your eyes to pre-adjust to darkness, so that you're not suddenly blinded if something happens and the power goes out, and you're dashing for the doors in darkness or smoke," explains Patrick Smith, an airline pilot and author of Cockpit Confidential.

"The emergency path-lighting and signs will also be more visible. And it makes it easier to see outside, which helps you to maintain at least a basic sense of orientation - i.e. which way is up."

Raising your window shade during take-off and landing is also part of the same strategy. 

"It helps you remain oriented, and also makes it easier for the flight attendants to assess any exterior hazards, such as fire or debris, that might interfere with an evacuation," says Smith.

The human eye can take up to 10 minutes to fully adapt to darkness, which is valuable time if you need to evacuate an aircraft in a hurry.

It's also thought to be the reason why pirates wore eye patches; the theory being that by keeping one eye in darkness it would be better prepared when a pirate suddenly had to go into the pitch black bowels of the ship.

This would have given them a distinct advantage when they were ransacking another ship, which would have required them to fight on the deck and below. Having an eye for light and an eye for night would also have allowed them to better defend their ship when it came under attack.

 

So now you know......
 

[Don Mega]

What if it is a daytime flight ?

[wprime]

41 minutes ago, Don Mega said:

What if it is a daytime flight ?

 

Then they don't

[worgeordie]

Most likely to calm the passengers.

so they cannot see the fear on others

faces.

regards worgeordie

[watcharacters]

 

 

just to throw into the mix...

 

Shades are required to be open during takeoff and landing so emergency responders can see into the craft in case of  an emergency.

 

Now how can we get  the airlines to stop recirculating the cabin air rather than  having fresh air brought in?  I'd  gladly pay a bit more per ticket to cover the filter maintenance cost.

[Ace of Pop]

They use Ford Batteries


Sent from my iPhone using Thaivisa Connect

[gk10002000]

The flight attendants do it because they are told to do it.  Few if any know or understand any of the technical reasons, or human factor reasons

[gk10002000]

48 minutes ago, watcharacters said:

 

 

just to throw into the mix...

 

Shades are required to be open during takeoff and landing so emergency responders can see into the craft in case of  an emergency.

 

Now how can we get  the airlines to stop recirculating the cabin air rather than  having fresh air brought in?  I'd  gladly pay a bit more per ticket to cover the filter maintenance cost.

You really don't want pure fresh air coming in, once the plane gets to altitude.  There is not enough oxygen in the air.  Most people would start to not feel well above about 15K feet, and as you get to the 20k and higher altitudes, few people would function normally and at 30 k feet, forget it.  The air handling system keeps an eye on things.

[watcharacters]

2 minutes ago, gk10002000 said:

You really don't want pure fresh air coming in, once the plane gets to altitude.  There is not enough oxygen in the air.  Most people would start to not feel well above about 15K feet, and as you get to the 20k and higher altitudes, few people would function normally and at 30 k feet, forget it.  The air handling system keeps an eye on things.

 

7 minutes ago, Ace of Pop said:

They use Ford Batteries


Sent from my iPhone using Thaivisa Connect

 

 

I thought they were Panasonic, Ace.

 

 

gk..     Are you under the impression the air handling system does a good job of germ filtering when people cough and sneeze without  covering their mouths?

[Gulfsailor]

3 minutes ago, gk10002000 said:

You really don't want pure fresh air coming in, once the plane gets to altitude.  There is not enough oxygen in the air.  Most people would start to not feel well above about 15K feet, and as you get to the 20k and higher altitudes, few people would function normally and at 30 k feet, forget it.  The air handling system keeps an eye on things.

The composition of air (21% oxygen) is the same on the ground as in high altitudes. The reason why it becomes difficult to breath at altitude is because the pressure is lower, thus there is less absolute oxygen to breath. Obviously the air brought into the plane from the outside gets pressurized, so you can breath it just fine. 

The reason why only a small percentage of  fresh air gets added every cycle is a matter of cost. It takes energy to pressurize and warm up the air.

In the old days when you were still allowed to smoke on board every cycle consisted of fresh outside air (after pressurizing and heating). 

[gk10002000]

1 minute ago, watcharacters said:

 

 

 

I thought they were Panasonic, Ace.

 

 

gk..     Are you under the impression the air handling system does a good job of germ filtering when people cough and sneeze without  covering their mouths?

Does a good job?  Not at all.  I was just addressing the oxygen content and pointing out the main reason they recirculate the air.

[cornishcarlos]

The flight attendants do it because they are told to do it.  Few if any know or understand any of the technical reasons, or human factor reasons

I think flight attendants are well versed in safety procedures and the reasons for certain protocols. They aren't just pretty "trolley dollies" anymore :)

[cornishcarlos]

They use Ford Batteries


Sent from my iPhone using Thaivisa Connect

Do Ford make batteries now ?

[Don Mega]

Just now, cornishcarlos said:

 

They aren't just pretty "trolley dollies" anymore :)

Aint that the truth, seen some right munters lately.

[gk10002000]

1 minute ago, Gulfsailor said:

The composition of air (21% oxygen) is the same on the ground as in high altitudes. The reason why it becomes difficult to breath at altitude is because the pressure is lower, thus there is less absolute oxygen to breath. Obviously the air brought into the plane from the outside gets pressurized, so you can breath it just fine. 

The reason why only a small percentage of  fresh air gets added every cycle is a matter of cost. It takes energy to pressurize and warm up the air.

In the old days when you were still allowed to smoke on board every cycle consisted of fresh outside air (after pressurizing and heating). 

agreed.  the heating of the air is a significant factor.  But if you look up how inefficient human lungs are you will see that quite a bit of the oxygen we inhale is exhaled unused. So once the air is heated and pressurized, the airline design attempts to reuse it.

[watcharacters]

19 minutes ago, gk10002000 said:

Does a good job?  Not at all.  I was just addressing the oxygen content and pointing out the main reason they recirculate the air.

 

I appreciate what you're saying about oxygen content but I also know the air in the cabin can be freshened rather than subject to constant recirculating but it isn't done so due to a maintenance cost.    At least that's what I garnered from an airline site I once read.   Was it incorrect?

 

Cheers,

 

This being a SEA based forum there must be tens of thousands of  commercial airline pilots as members as well as special forces trained soldiers  and astronauts..   Some of the pilots could surely  (not Shirley)  shed light on the subject.

[Ricardo]

1 hour ago, watcharacters said:

 

Shades are required to be open during takeoff and landing so emergency responders can see into the craft in case of  an emergency.

 

 

Also so passengers can see if there's a burning-engine, just outside the escape-door, before they open it ?

[Ace of Pop]

30 minutes ago, cornishcarlos said:

 

Do Ford make batteries now ?

 

O.K. Mr Pedantic Oggie, Batteries as supplied to Ford Thailand, that areas much use as most O.E. ones on Thai Vehicles. Id love that Pastie with a Cold Leo come lunchtime.

[cornishcarlos]

1 minute ago, Ace of Pop said:

O.K. Mr Pedantic Oggie, Batteries as supplied to Ford Thailand, that areas much use as most O.E. ones on Thai Vehicles. Id love that Pastie with a Cold Leo come lunchtime.

 

I'm flying back to U.K on Wed, so I'll have a nice pasty and a pint of Tribute on Thursday lunchtime for you :)

 

Happy Xmas 

[Don Mega]

1 minute ago, Ace of Pop said:

O.K. Mr Pedantic Oggie, Batteries as supplied to Ford Thailand, that areas much use as most O.E. ones on Thai Vehicles. Id love that Pastie with a Cold Leo come lunchtime.

 

I don't reckon the airlines purchase their batteries from Thailand no matter the manufacturer.

[watcharacters]

12 minutes ago, Ricardo said:

 

Also so passengers can see if there's a burning-engine, just outside the escape-door, before they open it ?

 

 

Excellent reminder and I most definitely forgot that.    But that certainly applies to the exit rows mostly.

 

Thanks, Ricardo.

[Ace of Pop]

Who cares, Cornish Carlos has serious topic worthy of mention.Tribute Ales and St Austell Brewery. The Ozz Gang lunchtime are experts on Brit Warm Beer being convicts from there.

 Stupid Buggers Brits, they stayed on wet cold island and send naughty geezers to a nice place to live.

[55Jay]

Woke up this morning and thought, "I wonder why the lights are dimmed on take off?". 

 

Fortuitous that I stumbled across this thread. 

 

 

[Rhys]

Thanks always wonder why as well.. cheers mate

 

[Jdiddy]

I always thought they did it on takeoff to lessen the electrical generation load on the engine in case of an emergency where every bit of power is needed

[Jdiddy]

I always thought they did it to lessen the electrical generation load on the engine in case of emergency where every bit of power is needed eg engine failure, last second go around

[Heng]

Binge watched Aircrash/Mayday earlier this year.   One thing that stuck out was that during evacuations for fire, you have 90 seconds on average and a very low chance of making it out if you're not within 5 rows from an exit.   

[rice555]

The outside air is heated with bleed air off the engines in heat exchangers,

the bleed air also is used to heat the leading edges to stop icing.

If I remember right, the cabin air is recycled every 7-8 mins. I didn't work A/C

but worked doors, emergince O2, water, seats, ELS and shiter's.

rice555