I hope this is the right forum to post this question in; please feel free to move it, if not.

I tend to fly at night a little more often than during the daytime, and on almost every flight I've been on where it was visible from the cabin, I've seen the pilots use the wing lights in conjunction with the landing lights for takeoff and approach/landing. If anything, the wing lights stay on longer/come back on earlier than the landing lights do. Doesn't matter which airline, or where in the world I am, that seems to be standard procedure. However, I've noticed recently when flying on American that they tend to use landing lights only, without wing lights, especially on takeoff. The pilots also seem to delay using either set of lights as late as possible, for example they will wait until just before starting the takeoff roll to turn them on whereas most carriers turn them on just before taxiing onto the runway. I thought it might just be a fluke the first couple of times, but after seeing this on several flights I'm wondering if it's just SOP at AA. Is there a reason their procedure for using lights is different than at most other carriers? This is genuine, avgeek-y curiosity, not an inherent criticism of AA.

Are you referring to the wing inspection lights? If so, it's likely just a difference in when they run their checklists and at hub airports you'll tend to find the hub carriers do certain things to be more courteous to other crews because they better understand how their lights impact other pilots and will only use the lights when required.

Not sure what you mean by "wing lights". Do you mean logo lights, which are on the wing and aimed at the tail? Or something else?

When you're talking about departure procedures, most carriers will take the runway with landing lights off. When cleared for takeoff, they will turn them on, then begin the takeoff roll.

From what I know the wing lights are preferably used during icing conditions to check ice build up on the leading edge of wings and engine.

trijetsonly wrote:

From what I know the wing lights are preferably used during icing conditions to check ice build up on the leading edge of wings and engine.

This is what they're designed for, however after a number of runway incursions, some airlines went to a lights on below 10,000 ft and when crossing a runway policy. for most carriers its strobes and wing lighs on when crossing a runway, and all lights on when lining up for takeoff. Some wont turn on the landing lights until cleared for takeoff.

As far as specifics for AA, seems like you might be right. A very non scientific observation of the last 3-4 AA planes taking off here shows no wing lights used. AA specifically has had odd policies over the years in regards to lights though. As a cost saving measure in the 90's and early 00's, they deactivated all the tail logo lights across their entire fleet. Someone had done the math, and determined they were a needless expense so they were all deactivated.

Might get a better answer in the tech ops forum if you want to ask the mods to move the thread.
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shamrock137 wrote:

As far as specifics for AA, seems like you might be right. A very non scientific observation of the last 3-4 AA planes taking off here shows no wing lights used. AA specifically has had odd policies over the years in regards to lights though. As a cost saving measure in the 90's and early 00's, they deactivated all the tail logo lights across their entire fleet. Someone had done the math, and determined they were a needless expense so they were all deactivated.
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Interesting! Maybe it's a related reason, then. And I'm glad I'm not the only one who's noticed the trend.

Here's an example of what I was referring to, comparing nighttime departures on an AA A319 vs. a DL A321:

AA: https://youtu.be/4fQFO7AJTqk?t=722 - the a/c taxies onto the runway with no additional lights (not even strobes), and the landing lights are turned on only when about to start the takeoff roll—no wing [inspection] lights
DL: https://youtu.be/1JXN21oOL8o?t=374 - the wing [inspection] lights & landing lights come on before even entering the runway

Obviously these are isolated examples, but from what I've experienced on other flights it seems to be a trend, so I thought there might be a reason for AA doing things differently

ADM94 wrote:

Here's an example of what I was referring to, comparing nighttime departures on an AA A319 vs. a DL A321:

AA: https://youtu.be/4fQFO7AJTqk?t=722 - the a/c taxies onto the runway with no additional lights (not even strobes), and the landing lights are turned on only when about to start the takeoff roll—no wing [inspection] lights
DL: https://youtu.be/1JXN21oOL8o?t=374 - the wing [inspection] lights & landing lights come on before even entering the runway

Obviously these are isolated examples, but from what I've experienced on other flights it seems to be a trend, so I thought there might be a reason for AA doing things differently

Yeah, AA seems to use the Auto function on their wing strobes across the Airbus fleet. This seems to be a holdover from the L-US side of things. The Airbus has a 3 position switch for the wing strobes, OFF, Auto and ON. Auto switches the strobes on when the aircraft becomes airborne and then switches them back off upon landing using a weight on wheels sensor. In the US anyway, I cant think of any other airline I've seen use this function, most just use on or off.

Edited to add a video example here

Probably the same as what we did at my carrier. At FL180 the turn off/ inspection lights came on to aid others to see us. At 10,000 we turned on the landing lights as now you're in most GA airspace. When cleared to land the nose taxi light came on.

shamrock137 wrote:

This seems to be a holdover from the L-US side of things.

I think it might even go back to being a holdover from the America West days...

shamrock137 wrote:

ADM94 wrote:

Here's an example of what I was referring to, comparing nighttime departures on an AA A319 vs. a DL A321:

AA: https://youtu.be/4fQFO7AJTqk?t=722 - the a/c taxies onto the runway with no additional lights (not even strobes), and the landing lights are turned on only when about to start the takeoff roll—no wing [inspection] lights
DL: https://youtu.be/1JXN21oOL8o?t=374 - the wing [inspection] lights & landing lights come on before even entering the runway

Obviously these are isolated examples, but from what I've experienced on other flights it seems to be a trend, so I thought there might be a reason for AA doing things differently

Yeah, AA seems to use the Auto function on their wing strobes across the Airbus fleet. This seems to be a holdover from the L-US side of things. The Airbus has a 3 position switch for the wing strobes, OFF, Auto and ON. Auto switches the strobes on when the aircraft becomes airborne and then switches them back off upon landing using a weight on wheels sensor. In the US anyway, I cant think of any other airline I've seen use this function, most just use on or off.

Edited to add a video example here

Yeah, I think I've occasionally noticed DL pilots using the auto strobes, too