B777 lights in dim

[etops skipper]

:ugh:Hello,

On my Fcom, nothing is mentioned about B777 (landing)lights in dim during flt . Only on MEL. Anybody has more detailed info about it? Company here says if not on pilots manual, you don`t need to worry, however it is on MEL.
Appreciate if anybody has more info.

Tks and season`s greetings

Etops Skipper

[NSEU]

When the nose gear is down and locked, the landing lights go into bright mode (28 volts AC instead of 24volts AC).

There is also a wing landing light heating system to help prevent thermal shock (which reduces the life of the lamps). When the nose gear is not down and locked, the airplane is in the air and landing lights are selected OFF, a small current flows through the lamps to keep them warm (in low light conditions, you can see the lamps glowing).

Rgds
NSEU

[etops skipper]

Hi NSEU,


Tks for posting. I had already assumed the lamp life and thermal shock,as well as the dim/bright with the gear up/down (similar to 767)

My curiosity remains on the fact that during cruise the lights are always in a dim state, and as you cross with a 777, the lights are always on (more noticeable at night). Sometimes other planes flash at you (normal), but when the flash from ldg light goes off, it goes back to dim. Is that associated to the ground air sensor, dim lgts at the overhead panel, do they remain on during daytime also?
I `d appreciate if you could refer any literature, web site etc, with more info on this system.
I`m from a time when you needed to know about your airplane, and nowadays a lot of info is lacking

Tks, happy flts

Etops Skipper

[NSEU]

My curiosity remains on the fact that during cruise the lights are always in a dim state,

The dim state you describe will most likely be the heater voltage illuminating the lamps, not the "dim" setting.

Here's a shot of a 744 with the heater voltage active (lights off).

http://www.iinet.net.au/[email protected]/GroundServiceLandingLight.jpg

The PSEU logic on some of our aircraft goes into air mode during Ground Service ops, turning on the heaters.

[etops skipper]

Hi NSEU,

Maybe I`ve picked the wrong words.
Yes, yhat`s the kindo of "dim" I mentioned, so that is due to the heaters; good, something I didn`t know.
Now, If I may, they would come on with the ground/air sensor logic?

Tks again, my guru...:8

E.S.