Flashing Landing Lights, inbound to YSSY

[Gribble]

Hey everyone, long time lurker-first time poster 

Me and my flatmate have been sitting out on the verandah in Northern Sydney, casually chatting about the world over a beer and a smoke (ciggarette, not the whacky stuff) when we noticed what looked like a southbound jet of the Qantas variety flashing its landing lights the whole way from what looked like the calga NDB until it passed out of view towards the airport. In my whole 18 months of being able to watch domestic jets fly over at night time i havent once seen one flashing its lights like this. Just wondering if anyone out there with a clue knows what might be going on? Radio Failure? Transponder failure? ATC telling him to flash them?

Thanks in advance!
Gribble.

[atcman23]

I'm not sure of the procedures and regulations in Australia, but here in the U.S., you would flash your landing light to acknowledge an instruction from ATC.  It could be a lost comms situation, where they could or hear or speak to ATC or a partial loss, where they could hear ATC but not speak to them.  Additionally, control towers have a light gun that uses a red, green, or white (white only on the ground) to communicate with pilots.  So this could have been the case.  I have seen landing lights that flash continuously on aircraft however, and I have no idea why.  That was on a small private aircraft, not an airliner.

[Jason]

It sounds like someone forgot to turn the pulse light toggle switch to the off position. No biggie, it just wastes a lot of light life.

[sunburn]

Here in the UK i live near a Police Helicopter base which is situated along the approach of a regional airport/cargo hub. When the police helicopters are landing/taking off/on station and there and an aircraft is coming along on the approach, the approaching aircraft would flash their landing lights to show they're around. They range from biz jets to heavies.

[rpd]

I have taken many SWA flights in the last few years and many of the 737's have the pulsing/flashing landing lights.  I am not sure what series aircraft I was on. 

I remember reading somewhere that the pulsing lights are simply for increased visibility and possibly bird strike prevention.

[YBBN]

Pulsing landing lights is also an essential tool for VFR flights flying either in CTA or OCTA or being given an instruction from ATC to sight an approaching IFR aircraft to maintain visual separation. Pulsing landing lights stand out for miles in the distance especially in degraded visibility such as smoke/haze.

[joeyb747]

I have taken many SWA flights in the last few years and many of the 737's have the pulsing/flashing landing lights.  I am not sure what series aircraft I was on.  

I remember reading somewhere that the pulsing lights are simply for increased visibility and possibly bird strike prevention.

SWA B737-200 series. Check out this pic...Note the port landing light is on, and the starboard landing light is off...

http://www.airliners.net/photo/Southwest-Airlines/Boeing-737-2H4-Adv/0639220/L/&sid=a5150d4d8c7767ef3fe381d7342c5373

As far as SWA goes, I think the -300 and -500 series may have had them too...

It's more common on corprate type jets then airliners.

[joeyb747]

Gribble, this should answer your question:

"Qantas Airlines, along with Pulselite lighting system vendor Precision Flight, evaluated the effectiveness of pulsed lighting in reducing birdstrike events. The full evaluation period ran from January 2005 through August 2007. Within that period, Qantas installed the lighting system on five Boeing 737-400s and five Boeing 737-800s and conducted normal operations with these aircraft for one year."

From article below:

http://www.aviationweek.com/aw/generic/story_channel.jsp?
channel=comm&id=news/BIRD061109.xml&headline=NTSB%20Seeks%20On-Aircraft%20Birdstrike%20Solutions