747400sp
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Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 2:01 am

Most planes nose gear is almost always on, but 747's nose light turn off at rotate and do not come on till touch down. I have notest that 747's do not land with there nose light on like other a/c since the early 90's maybe 80's, but the first time I notest that there nose gear light turn off at rotate, was during the take off scene in the movie Drop Zone. So could somebody tell me why 747 do this?


PS: My father told me Pan Am 747 use to turn there nose gear light on right before touch down, is this true.
 
kcrwflyer
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 2:21 am

I'm thinking it has to do with the angle of the light, and the angle youre viewing the aircraft from.
 
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jetmech
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 3:52 am



Quoting 747400sp (Thread starter):

The landing lights on the nosegear are able to be manually switched by the crew. IIRC, even if the lights are left on, they automatically switch off when the nosegear retracts. As far as I know, this is done by a simple rotary contact mechanism down in the nosegear wheel well itself.

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JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
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HAWK21M
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 10:25 am



Quoting JetMech (Reply 2):
even if the lights are left on, they automatically switch off when the nosegear retracts.

Its exactly that way on the B757.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
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jetmech
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 4:12 pm

Quoting HAWK21M (Reply 3):

I see. Talking about lights, I was observing a 737 NG approaching runway 16R at SYD this afternoon. The two lights under the fuselage were exhibiting a strange behaviour. As far as I could tell, they were alternately switching on and off. If I was not actually seeing things, why do these particular lights perform this switching pattern   .



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[Edited 2008-09-06 09:17:23]
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
corey07850
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 4:43 pm



Quoting JetMech (Reply 4):
I see. Talking about lights, I was observing a 737 NG approaching runway 16R at SYD this afternoon. The two lights under the fuselage were exhibiting a strange behaviour. As far as I could tell, they were alternately switching on and off. If I was not actually seeing things, why do these particular lights perform this switching pattern .

You aren't seeing things... Seems in the last few years the alternating landing light has been getting more popular. I see it a lot on corporate aircraft and occasionally on airlines. It's supposed to increase visibility as well as possibly aiding in scaring off birds
 
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jetmech
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 5:01 pm



Quoting Corey07850 (Reply 5):
It's supposed to increase visibility as well as possibly aiding in scaring off birds

I see. I was actually reminded of an emergency vehicle when I was watching the 737 this afternoon. It's good to know I wasn't seeing things. I was actually thinking that the lights were on all the time, and that it was the regular passage through small areas of cloud that were making the lights blink! The regular nature of the blinking should have made me reject this explanation immediately  blush  !

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
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HAWK21M
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 5:25 pm



Quoting JetMech (Reply 4):
As far as I could tell, they were alternately switching on and off. If I was not actually seeing things, why do these particular lights perform this switching pattern

Those are varying intensity landing lights....Increase the life of the filament & are visible a greater distance away due to its flashing.

regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
fr8mech
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 6:29 pm

The runway turnoff lights are controlled by a switch in the cockpit and by the nose gear squat switch. If the switch in the cockpit is left on, the lights will go out as soon as the aircraft nose gear breaks ground.

I can only assume this is to reduce crew workload on take-off. Leaving those lights on as the gear retracts will greatly shorten their life.

Near as I can recall, the B757/B767 work in similar fashion, nose gear landing lights included, though I think the switching is down through the down lock for the landing lights.
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HAWK21M
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RE: Why 747 Nose Gear Light Trun Off At Take Off?

Sat Sep 06, 2008 10:49 pm



Quoting Fr8mech (Reply 8):
the lights will go out as soon as the aircraft nose gear breaks ground

That would be an air-grd sense if not mistaken.Then thats different from the B757.

Quoting Fr8mech (Reply 8):
Near as I can recall, the B757/B767 work in similar fashion, nose gear landing lights included, though I think the switching is down through the down lock for the landing lights.

On the B757...gear up , taxi light off,gear down & aircraft in air, the Taxi light will function dim,gear down & Aircraft on ground.the taxi light will be at full illumination.

regds
MEL
I may not win often, but I damn well never lose!!! ;)

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