I live under one of SEA's flight paths for landing so I get a pretty good look of incoming flights. Tonight I noticed that the lights on the wings were flashing and there was a red light under the belly probably near the front wheel flashing. I've never seen this before. What could be the cause of this? Since it is dark here I couldn't see the logo on the tail but this was just a couple minutes ago.

The pilots just wanted to add some bling. You know, pimped out the plane. They pro'lly had chromium wheels, tinted windows and the works.

From what I've noticed, ALL the planes have those lights and use them for take offs, landings and taxiing. Here's an aritcle for ya:
http://www.boston.com/news/world/eur...nt_collisions/

The lights on the wings that were flashing are so-called STROBE lights taht are being switched on when entereing the runway for takeoff and switched off when leaving the runway but remain illuminated during the complete flight. They are designed as anti-collision lights.

The red flashing light is a so-called rotating beacon or anti-collision light that has to be illuminated before the engines are being started and shut off after the engines stopped. They are for collision avoidance as well as warning sign on the ground that the engines are running

Additionally, you will find navigation lights, on the left wing a red light, on the right wing a green light and at the tail a white light. They are designed to see in which direction an aircraft (or boat as well) is travelling at night/in bad weather. Commercial airliners however use them for the full duration of the flight.

Since all these lights are standard (strobe lights are however not mandatory on small airplanes like a Cessna 172 or Piper PA28, but still often used), you should be able to see them every time you have an airplane passing over you....

May I add a related question. During approach (and I think also Take Off) they activate strong headlights on the wings. Like the headlights/floodlights in your car.

On a recent night flight I was surprised that those lights were suddenly activated during normal flight on cruising altitude. As I checked about two hours later they were deactivated again.

What was that about?
W

The red/green/white lights - as captainiglo points out provide relative motion information.... and correspond to the port/starboard/masthead lights used on waterborne vessels...

I can only assume that those lights have the same arcs of visibility as their maritime equivalents? That is of course what makes it possible to asses heading to some extent just from the lights.....

Arcs of navigation lights are equal according to FAR

You mean assess, right?

They're called "aircraft landing lights" or ACLs, though they're also used on take-off for safety reasons and are supposed to be on whenever the aircraft is below 10,000 feet.

ACLs run on either 14 or 28 volts. The 14v kind can be used on a car with a few mods to its electrical system. It's illegal, of course, since they'll do a number on the vision of any driver coming the other way - but can come in handy once in a while if one is careful in using them, and are really good for getting revenge on a driver who tailgates you with his/her brights on. Here's a picture of how one guy decked out his old car with a few.

Thank you for your answer. My main question was why they were active in the middle of the flight at 30'000ft cruising altitude? ANd not just for some minutes. Or did the pilots some routine checks and forgot to turn them off?
W

My guess is that you're referring to the wing lights, which illuminate the leading edges so that icing phenomena may be ascertained.

And yes, we may forget to turn a light on or off (usually because our attention gets diverted by something else) but it doesn't happen often. The selection/de-selection of lights is procedurally dictated.

Whenever aircraft lights are not required to be illuminated, they may always be turned on at any time at the discretion of the pilot. Usually this is done when the pilot wishes to make the aircraft more visible to other nearby aircraft. At cruise altitude in a passenger jet this is uncommon, since air traffic control (ATC) is assigning altitudes and headings, and should be spacing aircraft a minimum distance from one another. Also, these jets are equipped with a radar-based traffic warning system (TCAS) which should let them know of the whereabouts of nearby aircraft. But anything can happen.

I also live under SEA flight path. Back in the 80's I worked swing shift for Alaska Airlines and was heading home just after midnight. As I drove under the flight path, SOMETHING came over my head that had the strobes going and there were more than I remember seeing on any other plane. Honest to God I thought aliens had landed at SeaTac..........it was the SST......

Was interesting a few months ago when flying AMS-DXB (and back) that the entire time we were over Iraq, those lights were illuminated.

Hhmm, thinking about it we were about in the same region (Ira*, Afghnaistan) as I saw the lights.
W

When ya make a spelling error... it is often a beauty!


ASSES indeed!!!!