I was just recently on a Southwest flight to BNA and when we left DTW we had to cross a runway (this was 6:00a.m. so dark) I had noticed that there was a light like the taxi or landing light flashing....one turns on the other turns off...I am guessing this is to indicate they are crossing a runway so other pilots can see them crossing the runway....but have any of you noticed that or is that a light feature in the plane.....it is modeled in the NGX???????I was just curious to see what people said about this.

If I remember correctly, some 737's are fitted with a flashing landing light option that does like what you said- flashed back and forth. I believe this is to try and ward off birds on approach/departure.I would love this to be installed in the NGX as an option and if I remember, someone at PMDG said they might look into it.

Edited February 12, 201214 yr by FDX016 - Nick

If it's an active runway, it shows "here I am, don't run into me". Just a way of being safe. Saw that on a Delta 738 leaving Detroit.

Edited February 12, 201214 yr by Kenny

I could see that as a way to ward off birds...but the pilots only turned it on when we were crossing the runway and back off when we were on the taxi way!!!!! I was just wondering if this was a normal procedure or something that all aircrafts had that I had not realized!!!

It's standard procedure to have landing lights on when crossing an active runway. I don't know of the alternating lights have a toggle or if they are just either on or off like normal landing lights. If its the latter case, then all the pilot was doing was turning on the lights and following procedure. Hence the reason they were only on when crossing the runway, and it would be the same procedure even without alternating lights.

Edited February 12, 201214 yr by FDX016 - Nick

As far as I know, SWA only has this on some of their classics (300/500's) I believe it may be an option on the NG's, and it is standard on a number of bizjets. I can specifically say the Falcon 50, 900, and 200's all have this standard. It's a 3 way switch: off, pulse, on (steady) I've also seen it on most of the Citations.

I noticed the exact same thing last week when I was on a British Airways B737-400 departing Amsterdam Schiphol late at night. When we crossed a runway during the taxi out the landing lights and strobes came on and then went off again once we'd crossed. It's just so that even in low visibility it is obvious to another aircraft which may be using that runway that there is another aircraft on it.

According to a little research, it's called a Pulse Light system.I found a couple videos with it.This one blinks them both on and off at the same time.

This Southwest flight does what you described, alternating landing light strobing in the daytime.

Alright...nice to learn something new!! Thanks for all the replies everyone!!!

That last vid, is that a Classic with winglets or is Boeing moving the landing lights back out to the flap tracks on the NGs now?

That last vid, is that a Classic with winglets or is Boeing moving the landing lights back out to the flap tracks on the NGs now?

Judging by the shape of the engine nacelle and the aft extension of the engine pylons I'd say it's a Classic.

Judging by the shape of the engine nacelle and the aft extension of the engine pylons I'd say it's a Classic.

It is a classic. Number of flap fairings (canoes), there are more on the NG's than the classics. Also SWA paints the canoes red on the -700's, gray on the -300 and -500's. This was done to make it really obvious for the ground crews so they'd be aware of the extra wingspan on the NGs. No word yet if the -800's will have them red or another color since the -800's are even wider than the -700's

The flashing landing lights are to increase visibility of the aircraft. A flashing light gets your attention better than a static light.Best regards,Robin.

The flashing landing lights are to increase visibility of the aircraft. A flashing light gets your attention better than a static light.Best regards,Robin.

Well, in the daytime.