New navigation lights on airplane...

[Externet]

Hi.  

On a recent flight, perhaps on an Embraer aircraft, noticed diffused flashing red lights on top of wings that I never saw before.   Anyone knows ?  Took a video but does not show the detail, I was unable to ask the pilot at exit.

They are near the 'ends' of wings tops, a centered row of 12, aiming upwards ?  Seem as diffuse as if the wing was translucent and lit from the inside.  Just curious.

L wingtip   ooooooooo ooo ===================     Main fuselage    ===================  ooo  ooooooooo    wingtip R

Found a image on the web to better explain the location of those lights on top of wings.

 

[exchemist]

9 hours ago, Externet said:

Hi.  

On a recent flight, perhaps on an Embraer aircraft, noticed diffused flashing red lights on top of wings that I never saw before.   Anyone knows ?  Took a video but does not show the detail, I was unable to ask the pilot at exit.

They are near the 'ends' of wings tops, a centered row of 12, aiming upwards ?  Seem as diffuse as if the wing was translucent and lit from the inside.  Just curious.

L wingtip   ooooooooo ooo ===================     Main fuselage    ===================  ooo  ooooooooo    wingtip R

Found a image on the web to better explain the location of those lights on top of wings.

 

Are you sure the aircraft was in clear air at the time? I've sometimes seen something similar when flying through very light cloud, which scatters light from the beacon lights on the underside so that a flashing glow becomes visible. Also could be something to do with the leading edge slat, or slot, that some aircraft extend for the approach and landing. I find it hard to think a diffuse beacon light would be helpful as a safety aid: you'd want something clear and bright, that could be seen for miles.

[Externet]

Thanks.  Nothing to do with leading/trailing edges nor extends.  On top of wings. Flashing during all clear night time trip. Seems Embraer RJ 145.  Commenting with a passenger on the right side window, we asked the flight attendant who guessed whatever to answer.

From the strong curiosity, found an almost decent image of the lights location, at daylight.  Center upper of image below.  Ahead of ailerons.  Unable to magnify.   The nearest is a group of three, then farther another nine, as in post 1 

L ooooooooo  ooo ==================================== ooo  ooooooooo R

 

Same details, in video, not flashing ---> https://www.youtube.com/watch?v=OfV9DnYPyo8&ab

 

[exchemist]

1 hour ago, Externet said:

Thanks.  Nothing to do with leading/trailing edges nor extends.  On top of wings. Flashing during all clear night time trip. Seems Embraer RJ 145.  Commenting with a passenger on the right side window, we asked the flight attendant who guessed whatever to answer.

From the strong curiosity, found an almost decent image of the lights location, at daylight.  Center upper of image below.  Ahead of ailerons.  Unable to magnify.   The nearest is a group of three, then farther another nine, as in post 1 

L ooooooooo  ooo ==================================== ooo  ooooooooo R

 

Same details, in video, not flashing ---> https://www.youtube.com/watch?v=OfV9DnYPyo8&ab

 

Ah, I see. I wonder if it is significant that these are immediately ahead of the aileron. I think I've seen such things on other aircraft and always assumed they were not lights but small protuberances to aid airflow over the aileron. I could imagine that, if that is what they are, it's possible that at night they reflect light from a beacon on the fuselage. But I'm just speculating.  I don't know if we have a pilot on the forum who can comment. 

Did these things seem to flash in unison or independently?

 

 

Edited September 21, 2022 by exchemist

[Externet]

Hi.

From memory, the belly red; the wingtip white strobe and the top red of fuselage beacons flashed sequentially; not simultaneous.  The questioned wingtop row of dots may be coincidental with one of them flashing.  The dots appeared like tiny 10mm diametre / 3mm high bumps when seen with the ambient light after aircraft stopped, but their diffused light was like 5cm diametre as seen on image.  There is a possibility of being reflective adhesive tape dots.  My vision is not superb, but was not a dream. 

[exchemist]

4 minutes ago, Externet said:

Hi.

From memory, the belly red; the wingtip white strobe and the top red of fuselage beacons flashed sequentially; not simultaneous.  The questioned wingtop row of dots may be coincidental with one of them flashing.  The dots appeared like tiny 10mm diametre / 3mm high bumps when seen with the ambient light after aircraft stopped, but their diffused light was like 5cm diametre as seen on image.  There is a possibility of being reflective adhesive tape dots.  My vision is not superb, but was not a dream. 

I'm sure you are not dreaming! Since the beacon is often a rotating light, like a lighthouse beam, I imagine it would be expected to illuminate each one in sequence, though very rapidly. But we probably need comment from a pilot. 

[Externet]

This is not a video, but the link to it shows - screen capture - Better image found :

 

[exchemist]

31 minutes ago, Externet said:

This is not a video, but the link to it shows - screen capture - Better image found :

 

I'm going to ask on another forum where there is an engineer who I think may have done some flying. 

[exchemist]

No reply yet from the person I was hoping might respond, but someone else reckons they are vortex generators to improve the air flow towards the wing tip, where, due to the flexing of the wing, it is (so I'm being told) the part likely to stall first as the angle of attack increases. 

[Externet]

The wings pictures above do not have winglets for reducing vortexes.

[exchemist]

4 minutes ago, Externet said:

The wings pictures above do not have winglets for reducing vortexes.

A winglet is to reduce wasted energy from wingtip vortices. That is a different thing. 

[exchemist]

On 9/21/2022 at 6:17 PM, Externet said:

Hi.

From memory, the belly red; the wingtip white strobe and the top red of fuselage beacons flashed sequentially; not simultaneous.  The questioned wingtop row of dots may be coincidental with one of them flashing.  The dots appeared like tiny 10mm diametre / 3mm high bumps when seen with the ambient light after aircraft stopped, but their diffused light was like 5cm diametre as seen on image.  There is a possibility of being reflective adhesive tape dots.  My vision is not superb, but was not a dream. 

Here is the best reply I got on the other forum:

"They are vortex generators. They generate tiny vortexes very close to the wing surfaces, thereby disrupting the laminar flow near the wing.

One of their most important functions is to make the stall break more gradual. If one wing of the aircraft stalls suddenly while the other wing is generating lift, the aircraft will roll violently towards the stalled wing. Using ailerons to try to counter this will just make it worse since ailerons increase the (effective) angle of attack of the wings when deflected downward, and thereby deepen the stall.

They also slightly reduce stall speed by ensuring laminar flow is NOT maintained. This is somewhat counterintuitive since laminar flow is a very efficient regime for an airfoil to work in. But in a laminar flow airfoil, again the stall break happens very suddenly. The turbulence created by the vortex generators ensures that any stall occurs gradually by disrupting the (primarily) laminar flow over the wing, and allows the wing to keep flying while partially stalled.

They also increase drag and reduce cruise speed at a given power setting. They are still seen as worth the tradeoff because they increase maximum takeoff weight by providing more margin against violent stalls at low airspeed, and the slowest airspeed that an airplane can get off the ground is one of the primary determinants in both runway length needed and maximum safe takeoff weight for a given runway."

 

So my guess is they may look like lights at night, due to being illuminated by the rotating beam of a fuselage navigation beacon, but in fact they are vortex generators.