What is the proper position for the landing lights when on the runway in a line up and wait position?
Counter-intuitively, the FAA answer (see chart on page 1-9 and text on page 1-10) is actually, they should be off during the line-up-and-wait phase.
When cleared to ...
“Line up and wait”—when entering the departure runway without takeoff clearance, turn on all exterior lights (except landing lights) to make your aircraft more conspicuous.
Then when takeoff clearance is received, the expectation is that landing lights will be turned on.
The best rationale I've seen for this is so that Tower controllers (and other aircraft) have an immediate visual cue that an aircraft "on the numbers" understands that it has been cleared for takeoff, or not.
Another FAA document, SAFO 11004 (these are "best practice" recommendations, not requirements):
o Taxi with taxi light on when moving, off when stopped.
o Turn on all exterior lights when crossing any runway.
o If cleared to “Line Up and Wait”, turn on all exterior lights except landing lights.
o When “Cleared for take-off”, turn on all exterior lights, including landing lights
o If you see an aircraft in take-off position on a runway with landing lights ON, that aircraft has most likely received its take-off clearance and will be departing immediately.
I’d have it on for visibility. Since you’re on the runway and pointed forwards, no landing airplane will see it, and no airplane in the pattern will be really close. No airplane taking off will see it because they don’t have a rear view mirror.
It means one less thing to do before taking off, and lets you focus on the remaining checklist items before departing.
I’d turn it on once in position.
If you intend to use your landing lights, there's no reason they should be off as your aircraft crosses the hold short position. At a minimum it will serve to increase your visibility to other aircraft and service vehicles. Taxi/ landing light courtesy does not apply to aircraft that are on an active runway.
Let's take this question from a position of logic- arguably you are in the most vulnerable position with traffic approaching from behind and your recommended to sit in the dark? That does not make a lot of sense to me. The landing light would not blind the inbound traffic, but rather cast a gentle light down the runway. I see two benefits from having the light on – The controller would advise the landing traffic that there is an aircraft on the active and waiting, why not make the visibility of said aircraft a little bit easier? Also as previous mentioned the taking off traffic that is one less thing to do. Do your lights camera action when taking the active runway including the landing light