Flight Crew Commercial
Situational Awareness; Distraction; Fatigue
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
General None Reported / Taken
Airport; Human Factors
We pushed back from the gate; requested taxi and were told 'taxi to Runway 8R via ramp.' No taxiways were assigned. I completed the engine start and immediately went into the taxi and before takeoff checklist/flows. The Captain taxied out and crossed what he thought was the approach holding line for 8R not realizing that doing so took him onto the extended threshold of 8R. After I finished the checklist and flows I noticed we were on a threshold and questioned him. He said no this is the approach area and the runway starts ahead. At exactly that time the Tower called and advised we had taxied past the hold short area but that it was no problem and that we were cleared for takeoff. Nothing further was said by the controller about the occurrence. The flight continued with no other issues.We were both tired from early wake up calls on the last leg of day four. This was a VERY short taxi from gate to runway and I was preoccupied running all the needed flows and checklists to get plane ready for takeoff. 90 percent of that time my head was down or occupied on flows. It is also a VERY confusing area transitioning from the ramp to the runway. [There are] very confusing markings in that area.Due to very short taxi and knowing this is a confusing area on the ramp we should have completed checklists/flows as much as possible prior to commencing taxi so that both sets of eyes could be focused on the taxi.
While the First Officer was occupied by checklists during a very short taxi to Runway 8R at ELP the Captain taxied across the runway hold short line without a clearance. No conflicts resulted and the Tower cleared them for takeoff. The First Officer reported fatigue as a contributing factor.