Date: 201703
Local time of day: 1801-2400
Location: LAS.Airport, NV
Flight conditions: VMC
Light: Night
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground LAS
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Workload; Situational Awareness; Confusion; Communication Breakdown
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Excursion Taxiway
Detector: Person Flight Crew
When detected: Taxi
Result: Air Traffic Control Provided Assistance; Flight Crew Took Evasive Action; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented
Contributing factors: Environment - Non Weather Related; Human Factors; Airport
Primary problem: Human Factors

Narrative: We were given a wheels up time on our initial call to Ground and were given taxi instructions to 7L at A8 via B. As we were taxiing; ground told us to pull off into Holding Pad 1. After holding for a few minutes; ground instructed us to taxi to 7L at A8 via B. It was very dark and difficult to see any taxi lines departing the pad. I began taxiing toward the green taxi lines that I saw toward our left and toward A6. In my mind I was thinking that Taxiway C was in front of us and Taxiway B was on the other side of C as it is going out from Spot 10. In reality Taxiway C ends there at Holding Pad 1. ATC asked us if we were turning left which was when I realized my mistake and started a right turn. My FO told me to STOP because we were too close to the edge of the taxiway to make a safe turn back to the right. We were too close to the unpaved area and told ATC we were going to need to call for a tug to be pushed back. I called our Operations. They coordinated with for a pushback back into holding pad 1. After starting the engines and performing the appropriate checklists and briefings for the new runway (1R) and taxi instructions; we taxied to 1R via B; D.I need to remember that even though I'm very familiar with LAS; it is very important to brief the taxi instructions and communicate with my FO. Had I verbally said what I was doing; my FO would have had the opportunity to correct me. Also; before I release the parking brake; I need to look at the route on the taxi chart even though I'm familiar with the airport. Another thing that would be a big help in situations like this would be to install taxiway edge lights on the taxiways.


Second narrative: This was at night and the crew could not see any discernible markings showing an exit path south of Holding Pad 1 onto Taxiway B. We began slowly taxiing south from Holding Pad 1. My expectation was that we would turn right (westbound) onto Taxiway B. I momentarily looked down to adjust my map light intensity; and when I looked up; I realized we had not yet begun our right turn (my expectation). I looked right to clear Bravo Taxiway westbound and realized that the edges of that taxiway were not immediately discernible - it just blended in with the holding pad (northern edge) and in-field dirt area (southern edge). I looked left and noticed what appeared to be green taxiway lights for B. Since it appeared we had crossed over the taxiway centerline and had not yet made a 90 degree turn to the right; I told the Captain to stop; which she immediately did. It was then realized that the aircraft's nose wheels were now too close to the southern edge of Taxiway B to execute the required 90 degree turn westbound onto Taxiway B. We contacted Station Operations and coordinated with ATC to have one of our tug vehicles push us back in order to provide us with the necessary distance from the taxiway's edge in order to execute the required turn onto Taxiway B.We should have better verbalized our plan for taxiing off the holding pad onto Taxiway B and emphasized the lack of discernible taxiway markings from where we were holding on the pad. I should have kept my attention outside during the event and dimmed the map light after we were established westbound on Taxiway B. It would be very beneficial to all aircrew to have a line painted or perhaps a line of lights from Holding Pad 1 leading onto the centerline of Taxiway B so that anyone departing that pad at night or in low visibility conditions could determine with 100 percent certainty where the pad ended and where the taxiway began and to help align the aircraft onto the taxiway centerline from the holding pad.


Synopsis: Air carrier flight crew reported continuing on Taxiway B to Runway 7L. Exiting Holding Pad 1; the crew did not see the Taxiway B markings and continued straight until too close to the taxiway edge to safely turn. A tug was sent to assist.