Most airlines here in the US have FL180 as "lights on" altitude. Exceptions would be for aircraft that have retractable/extendable landing lights, where it's usually 10,000ft/250kts.
Here at AA on the Boeing fleet, lights come on descending through FL180.
However, on our MD80 fleet (retractable lights) the wing landing lights were Captain's discretion: the company actually discourages the use of those lights when conditions don't warrant them (bright day VFR?) to save fuel and landing light maintenance plus eliminating the rumble they produce. Never liked that policy - to me, conditions ALWAYS warrant their use for T/O and landing.
Last edited by aa73; 16th May 2013 at 01:04.