Every plane on our fleet extinguishes them automatically when the gear comes up.

It's just to keep the flow smooth, really.

Flash back and forth, like strobes inside the same area as the landing light. If you watch the video you will notice it. It's a safety feature so other pilots can see you easier.

 

I will try to post a video (on vacation) my PMDG 777 has "Wig Wag" strobes in the landing lights, I thought it was an issue with FSX and ignored it, It only does it when the gear is up.

 

I know, I know...Necro post, but hey everyone else is doing it.