I have seen many times topics about aviation lights usage, but never clearly explained.Can someone give us a good explanation about aviation usage of lights(with some references - FAA or something like that)and how is applied on 737NG, some real-world 737NG pilot maybe? Thanks

What you ask for is exactly the topic of the threads you mention. Minus the FAA reference maybe, but even without that the basic usage is common sense. Everything else is optional and highly customized on an per-airline basis and what SOPs they implemented.

I think there has to be some references, i don't believe that each airline sets its own rules without some general rules

This is more or less what it says in the 737 Technical Guide: Gangbar Switch - Operates the outboard or retractable landing lights (depending on 737 model) and the inboard landing lights simultaneously. Note that it is a three position switch, the intermediate stage is for light extension only, this is because when it used to be a two-position switch (pre 1969 model 737s), the lights would come on as they extended and it would shine on clouds at they rotated into their extended position, and if you were passing through clouds that could cause a distraction/dazzle with reflections from clouds, so it is normal practice to use it in stages rather than flipping it all the way in one go, if in cloud. Retractable Landing Lights - These are what replaced the outboard landing lights on earlier 737s, they should be used at or below 250 knots when landing. Boeing are considering relocating these on the NG back to where they were on earlier 737s because they are prone to damage from flying stones and such, so you should also be careful about using them if you think that is likely. Inboard Landing Lights (Fixed Landing Lights on the NG) - Used for all landings, both night and day, to make your aircraft more conspicuous. Runway Turnoff Lights - Used at night on badly-lit runways. Taxi Lights - Used whenever the aircraft is in motion, it switches off automatically when the gear retracts, but only on late model 737s, earlier ones you have to switch it off manually. Logo Light - Although they are basically to advertise the airline by lighting up the logo, most pilots will use them for additional visibility if they feel it is warranted. Position Lights - Often used in the day, they are compulsory at night. Strobe Light - although you can put them on before, most pilots follow an unwritten rule whereby they will turn them on when entering a runway and off when leaving it, because they are extremely bright and can dazzle other pilots, so their use on taxiways is often frowned upon. Anti-Collision Light - Basically you have them on whenever the engines are running. Ground personnel use these as a signal to determine whether it is safe to approach an aircraft. You should also note that it is considered a courtesy to not blind ground personnel with any of the other lights! Wing Lights - These illuminate the wing so you can inspect it for ice accretion. Wheel Well Lights - Used for the pre-flight walkaround. On all except on NG's they are also used when using the landing gear view port, which of course the NG does not have. There is also the emergency light system, which works off a battery and can be operated either by the flight deck or cabin crew in an emergency. These illuminate the aisle and doorways in the event that an emergency evacuation is necessary. Al

Additionally, Sec. 91.209 — Aircraft lights.No person may:(a) During the period from sunset to sunrise (or, in Alaska, during the period a prominent unlighted object cannot be seen from a distance of 3 statute miles or the sun is more than 6 degrees below the horizon)—(1) Operate an aircraft unless it has lighted position lights;(2) Park or move an aircraft in, or in dangerous proximity to, a night flight operations area of an airport unless the aircraft—(i) Is clearly illuminated;(ii) Has lighted position lights; or(iii) is in an area that is marked by obstruction lights;(3) Anchor an aircraft unless the aircraft—(i) Has lighted anchor lights; or(ii) Is in an area where anchor lights are not required on vessels; or(:( Operate an aircraft that is equipped with an anticollision light system, unless it has lighted anticollision lights. However, the anticollision lights need not be lighted when the pilot-in-command determines that, because of operating conditions, it would be in the interest of safety to turn the lights off.[Doc. No. 27806, 61 FR 5171, Feb. 9, 1996]Charlie Coulon

Thanks Al, This is the most comprehensive explanation so far

I foun this on airliners.net forums: Airline SOP AA Policy is.... 1. Fixed Navigation Lights (Red, Green and White)Night or Dusk: OnDay: May be left off at the Captain’s discretion. 2. Red Anti-Collision Beacon / LightsGround Operations: On when an engine is running or whenthe aircraft is about to be moved or is moving.In Flight: On at all times 3. Wing Illumination and Runway Turnoff LightNight or Dusk Operations: On from the time the aircraftenters the active runway (crosses the hold short line) fortakeoff until reaching FL180 and during the descent fromFL180 until clear of the active runway after landing. May beleft off at the Captain’s discretion.Day Operations: May be left off at the Captain’s discretion. 4. Taxi LightNight or Dusk Operations: Turn on taxi light (low) when takingposition on the runway for takeoff. Leave light on untilafter takeoff. Turn on for landing no later than final approach.Day Operations: May be left off at the Captain’s discretion. 5. Landing LightsTurn on after takeoff clearance is received and the aircraft ison the active runway (across the hold line). Turn off aftertakeoff at the Captain’s discretion. Prior to landing, turn on atFL180 and turn off after exiting active runway. 6. High-Intensity (Strobe) LightsTurn on (when applicable) prior to commencing takeoff rolland turn off (when applicable) after landing. Strobe lightsmay be turned off during daylight hours when above FL180. ...and someone's flight school SOP:Taxiing: Taxi light ON, LDG light OFF, Strobe OFFEntering an active runway: Taxi ON, LDG, ON Strobe, ON"Cleared for takeoff": Taxi OFF, LDG ON Strobe ONClimb (usually 1/2 way to cruise alt): Taxi OFF, LDG OFF, Strobe ONDecent: Taxi OFF, LDG ON, Strobe ON"Cleared to land": Taxi ON, LDG ON, Strobe ONVacating a runway: Taxi ON, LDG OFF, Storbe OFF