Hi Guys, and Gals..why use landing lights?
The life of the bulb [globe] will be shortened by turning it on and off, at short intervals [of course, if you NEVER use it, it will probably outlast you].
"See, and be seen", is probably the best explanation - and that applies to being seen by other pilots, AND our feathered, winged friends...the ones who can cause a LOT of damage, if they impact with an aeroplane.
In the Airline I'm currently with [the 5th in my ever decreasing lifespan], we leave the landing lights on 'til 10,000' [the previous one left them on until reaching cruise level..FL350 or 290, or whatever].
Most birdstrikes occur below 10,000', but in a high traffic density scenario, leave the buggers on, all the time...from start of taxi 'til engine shutdown. Saves you having to think too much about it......and MIGHT save your life just once.
Is your life worth the cost of a landing light??!!