Strobe Light Patterns

So I live near the approach path of a small but busy airport that gets many, MANY A320s and 737s. I watch these planes on approach quite frequently. When they are far away, I usually try to identify whtyer it’s a Boeing or Airbus as they have different strobe patterns. But I frequently notice that some patterns are different, though it’s an Airbus or Boeing. For example, the other day, a 737, which’s strobes flash once per second on BOTH wings at the SAME time, had it’s strobes flashing with the left strobe first then the right strobe, still once per second, but not simultaneously. Another example is an Airbus A320 was coming in, and it’s strobes are normally twice per second, the second flash following the first in quick succession (flash flash, flash flash) on both wings. But this one, the left wing was flashing twice like usual, but the right wing was flashing once, like a 737.

So, does anyone know what these mean (or don’t mean)? I was considering maybe it’s a faulty strobe, but I find that unlikely in such a heavily regulated industry (and it’s not like once in a while, I see something like this everyday)

Edit: Also, the other day, I saw a 737 with a 787 like strobe, not a quick flash, but a bit longer, but it’s likely this 737 was equipped with LED strobes.
Also, I just saw an A320 with the strobe pattern I explained above, and here’s one more thing I noticed. The wing with the normal two flashes, the light wasnt as bright. The wing with the one flash was much brighter. Like the double flash split it’s brightness into two and the single had all it’s brightness in one flash 😂


Hi looks like it is based on manufacture preference but, I know there there are diffrent selections as ok or pulse in the cockpit.

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Yes, I know about the manufacturer preference, but these seem a bit odd. Do you know exactly what pulse and ok would be like? Thx 😀

The Strobe patterns are largely down to the type of light all the new 737 with LED Strobes have the steady pattern where as the older 737 without the LED’s flash traditionally and Airbus has opted to to stay with traditional method regardless if the strobes are LED

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Yeah I don’t think it’s a manufacture preference (this case). Maybe it was configured to accommodate the airspace restrictions?

Well on some of the older planes there are double lights on the wing that are flashing not in synchronization so that’s why.

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Yes that’s true, but why the odd patterns?

@Ark_of_Ahmed.IF yea I thought of that too, but then again, how come majority of the planes come with their standard strobes, and only some with these other ones?

Check out this link there seems to be some good information here.


that’s a good link. I saw that a couple weeks ago, but I felt like it didn’t answer this specific question. I understand the difference between airbus and Boeing’s strobe pattern, but I can’t find anywhere where it mentions why one strobe would flash before the other, or only once compared to the other one flashing twice. And if they did install new lights, I would assume it would still need to be in sync with the other. That’s like the hazard lights in our cars and one side flashes more frequently than the other 😆

Because some planes have 2 strived one forward facing and one backward facing and those flash not toghther but at diffrent times.

I know Southwest 737-8H4’s have the new strobes, when both blink at once…

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This one has some visuals, it might help xD

What I studied in school was that each lights must flash within a given time, how it flashes is how its designed. Cant tell for sure =p Im not an electronic technician but I guess theres some idea regarding this concept.

I may be wrong but I believe the aircraft manual for the maintenance people probably includes these information, If you can find it, you might be able to observe the differences.

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