read FAA AC 120-74a a snippet posted below
8. USE OF EXTERIOR AIRCRAFT LIGHTS TO MAKE AIRCRAFT MORE CONSPICUOUS. a. General. (1) Exterior aircraft lights may be used to make an aircraft operating on the airport surface more conspicuous. Pilots may use various combinations of exterior lights to convey their location and intent to other pilots, air traffic control, and ground personnel. Certain exterior lights may also be used in various combinations to signal whether the aircraft is on a taxiway or on a runway, in position on the runway but holding for takeoff clearance, crossing an active runway, or moving down the runway for takeoff. (2) Because adherence to the guidelines in this AC are voluntary and aircraft equipment varies, flightcrews are cautioned not to rely solely on the status of an aircraft’s lights to determine the intentions of the flightcrew of the other aircraft. Additionally, flightcrews must remember to comply with operating limitations on the aircraft’s lighting systems. b. Exterior Lights. To the extent possible and consistent with aircraft equipage, operating limitations, and flightcrew procedures, pilots should illuminate exterior lights as follows: (1) Engines Running. Turn on the rotating beacon whenever an engine is running. (2) Taxiing. Prior to commencing taxi, turn on navigation, position, anti-collision, and logo lights, if available. To signal intent to other pilots, consider turning on the taxi light when the aircraft is moving or intending to move on the ground, and turning it off when stopped, yielding, or as a consideration to other pilots or ground personnel. Strobe lights should not be illuminated during taxi if they will adversely affect the vision of other pilots or ground personnel. (3) Crossing a Runway. All exterior lights should be illuminated when crossing a runway. CAUTION: Flightcrews should consider any adverse effects to safety that illuminating the forward facing lights will have on the vision of other pilots or ground personnel during runway crossings. (4) Entering the departure runway for takeoff or “position and hold.” When entering a runway either for takeoff, or when taxiing into “position and hold,” flightcrews should make their aircraft more conspicuous to aircraft on final behind them and to ATC by turning on lights (except for landing lights) that highlight the aircraft’s silhouette. Strobe lights should not be illuminated if they will adversely affect the vision of other pilots.
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9/26/03 AC 120-74A
(5) Takeoff. Turn on landing lights when takeoff clearance is received, or when commencing takeoff roll at an airport without an operating control tower. NOTE: The SOP of turning on landing lights when takeoff clearance is received is a signal to other pilots, ATC, and ground personnel that the aircraft is moving down the runway for takeoff.