B737 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown; Ground Incursion Runway
Flight Crew Rejected Takeoff
Human Factors; Procedure
We were cleared for takeoff on Runway 26R in LAS. The Captain transferred the controls to me and I advanced the power and the aircraft began to roll. Shortly after we started to move; the red runway status lights illuminated; indicating it was unsafe to take off. Neither of us saw an aircraft approaching the runway to trigger the lights to illuminate. The Captain called for a reject and stopped the aircraft. We were about 50 KIAS when he rejected the takeoff. ATC asked if we needed assistance and we told them no and why we had rejected. We exited to the left at A2; turned the aircraft around; and held short of 26R at A2. The Captain explained what had happened to the passengers once we were stopped. We loaded performance data for a takeoff at A2 and ran the Departure Plan Checklist. We discussed the need to run the brake cooling; but we decided that since we had rejected at such a slow speed; it was not necessary. During that time; ATC cleared another flight for takeoff and the pilot told ATC the red lights were still on. Obviously they were turned off soon after; because they departed shortly after that. Once our departure data was loaded; we were cleared for takeoff from 26R at A2 and performed a normal takeoff. The following day we were discussing again whether or not we should have run the brake cooling. I am not sure if; as a matter of procedure; we should have done it even though our reject was such a slow speed. Looking back; I suspect it probably was something we should have done. I believe we were correct in rejecting the takeoff since we didn't know why the lights came on. It would be interesting to find out why they did come on since we never saw another aircraft that could have made them turn on. We probably should have run the brake cooling as well just to be sure.
B737 First Officer reported a slow speed rejected takeoff due to the illumination of the red runway status lights.