Dimming cabin lights
Guest
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For Quavion. I have flown the 747-200, 300 and 400 and am not aware of any such problem with the landing lights; they can be switched off on the ground or inflight. When in flight and clean, they operate on reduced voltage.
Some carriers choose not to have a taxi light and use the landing lights on the ground instead.
Another example of strange thinking!
Some carriers choose not to have a taxi light and use the landing lights on the ground instead.
Another example of strange thinking!
Guest
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"Very cheap insurance, but if your airline thinks the bulbs are more important than the
safety of the airplane and all aboard, that merely proves my point."
Agreed, but it might not be quite as cheap as you think
Sure, bulbs are relatively cheap, but if you start adding labour costs, cherry picker hire/purchase costs (if we're talking 747's), delay costs (if headed to a place where logo lights are compulsory),...
Some aircraft now have 3 lamps per side (probably not for visibility, but for redundancy).
Rgds.
Q.
safety of the airplane and all aboard, that merely proves my point."
Agreed, but it might not be quite as cheap as you think
Sure, bulbs are relatively cheap, but if you start adding labour costs, cherry picker hire/purchase costs (if we're talking 747's), delay costs (if headed to a place where logo lights are compulsory),...
Some aircraft now have 3 lamps per side (probably not for visibility, but for redundancy).
Rgds.
Q.
Guest
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"I have flown the 747-200, 300 and 400 and am not aware of any such problem with the landing lights;"
So this means it doesn't exist, Boofhead?
The latest info I have is that the PSEU (Air/Ground computer), on power down, has the possibility of latching in either Air or Ground mode. Latched in Air mode, the PSEU will put the lights on dimly when the aircraft is powered by the Ground Service Bus.
Being a pilot, I doubt very much that you've seen a -400 powered by the GSB ... and would probably complain if it was.
Q.
So this means it doesn't exist, Boofhead?
The latest info I have is that the PSEU (Air/Ground computer), on power down, has the possibility of latching in either Air or Ground mode. Latched in Air mode, the PSEU will put the lights on dimly when the aircraft is powered by the Ground Service Bus.
Being a pilot, I doubt very much that you've seen a -400 powered by the GSB ... and would probably complain if it was.
Q.
Guest
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Sorry Quavion, I don't follow your points.
Maintenance is usually done under contract, so cherry pickers and such will not cause extra cost. If the bulb is out the MEL can be used to get to Base where the lights can be fixed by your own blokes who are paid whether they are fixing the airplane or not.
The landing lights on ground power are not really relevant, are they?
Maintenance is usually done under contract, so cherry pickers and such will not cause extra cost. If the bulb is out the MEL can be used to get to Base where the lights can be fixed by your own blokes who are paid whether they are fixing the airplane or not.
The landing lights on ground power are not really relevant, are they?
Guest
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So what's the real reason for dimming the cabin lights or has it been well and truly lost in the myths of time. Is it for a lovely view of the towns at night or secretly because few passengers eat carrots for night vision nowadays - preferring fast food.
Guest
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My brother-in-law asked the original topic question and the combined 50 years of experience in the family was unable to give a positive reply.
What we have figured out is this.
1. Night adaption.
2. Subconscious learning. These were the last lights on and they mark the exits.
3. Improved view out for interested passengers.
4. The warm, dark environment is relaxing, thus having a soothing effect on nervous pax.
5. It says so in th e book!
Anymore guesses?
What we have figured out is this.
1. Night adaption.
2. Subconscious learning. These were the last lights on and they mark the exits.
3. Improved view out for interested passengers.
4. The warm, dark environment is relaxing, thus having a soothing effect on nervous pax.
5. It says so in th e book!
Anymore guesses?
Guest
Posts: n/a
"Maintenance is usually done under contract, so cherry pickers and such will not cause extra cost."
[To Boofhead] Unfortunately, there are certain things under many aviation maintenance contracts which don't incur extra costs and there are certain things which do. Our airline charges customers extra for things like cherrypickers. An engineer with a screwdriver comes a lot cheaper than an engineer with a cherrypicker :-) And on the subject of contracts.... A daredevil handyman with a stepladder would obviously be cheaper to contract than an engineer with a cherrypicker... but, thankfully, there are laws in many countries to prevent this.
"If the bulb is out the MEL can be used to get to Base where the lights can be fixed by your own blokes who are paid whether they are fixing the airplane or not."
But what happens when an MEL specifies that an item be fixed/fitted before the aircraft departs to a country? I must admit, I hadn't read our Logo Light MEL for a while and had forgotten the details (so I re-read them):
It specifies that if the lamps are inoperative, the aircraft can depart provided TCAS is OK. However, when going to the USA, operations are restricted to one night arrival and one night departure only. Sounds OK, too, but on some days our aircraft have to make three stops in the USA before they return home.
"The landing lights on ground power are not really relevant, are they?"
Previously, I was simply commenting on what someone (else) perceived as a "feature" (rather than a design bug). You _seemed_ to suggest that I didn't know what I was talking about simply because you had never come across this anomaly before (in your many years of experience)(???). I apologise if this was not the case.
Rgds.
Q.
[To Boofhead] Unfortunately, there are certain things under many aviation maintenance contracts which don't incur extra costs and there are certain things which do. Our airline charges customers extra for things like cherrypickers. An engineer with a screwdriver comes a lot cheaper than an engineer with a cherrypicker :-) And on the subject of contracts.... A daredevil handyman with a stepladder would obviously be cheaper to contract than an engineer with a cherrypicker... but, thankfully, there are laws in many countries to prevent this.
"If the bulb is out the MEL can be used to get to Base where the lights can be fixed by your own blokes who are paid whether they are fixing the airplane or not."
But what happens when an MEL specifies that an item be fixed/fitted before the aircraft departs to a country? I must admit, I hadn't read our Logo Light MEL for a while and had forgotten the details (so I re-read them):
It specifies that if the lamps are inoperative, the aircraft can depart provided TCAS is OK. However, when going to the USA, operations are restricted to one night arrival and one night departure only. Sounds OK, too, but on some days our aircraft have to make three stops in the USA before they return home.
"The landing lights on ground power are not really relevant, are they?"
Previously, I was simply commenting on what someone (else) perceived as a "feature" (rather than a design bug). You _seemed_ to suggest that I didn't know what I was talking about simply because you had never come across this anomaly before (in your many years of experience)(???). I apologise if this was not the case.
Rgds.
Q.
Guest
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Cabin Lighting: -
Must be dimmed before every take-off and landing
Must never be in total darkness during flight.
http://www.newscientist.com/lastword...3machines.html
Must be dimmed before every take-off and landing
Must never be in total darkness during flight.
http://www.newscientist.com/lastword...3machines.html
Guest
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During emergency training we were told that the main reason for dimming of cabin lights is to enhance recognition of an exterior fire, should any rejected T/O or emergency during landing occur.
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This Airbus is o.k., but why did it come with a RENAULT key ??
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This Airbus is o.k., but why did it come with a RENAULT key ??
Guest
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You guys are getting your knickers in a twist without actually pointing to a definitive study or case.
Most of the ideas put forward here are simply the ideas that you heard way back when and never questioned. Reminds me of the thread on the space shuttle booster diameter being determined by the designers of Roman roads.
Anybody got a REASONED reason for dimming/not dimming the lights?
Most of the ideas put forward here are simply the ideas that you heard way back when and never questioned. Reminds me of the thread on the space shuttle booster diameter being determined by the designers of Roman roads.
Anybody got a REASONED reason for dimming/not dimming the lights?
