A nighttime breakdown in communications between the flight crews of two aircraft; the local controller and the ground controller resulted in a runway and taxiway incursion and a ground conflict between the two aircraft.
Synopsis
A nighttime breakdown in communications between the flight crews of two aircraft; the local controller and the ground controller resulted in a runway and taxiway incursion and a ground conflict between the two aircraft.
Narrative
I received a clearance from Portland Ground Control to taxi from the ramp to Runway 10L for takeoff. The following clearances in quotations are as close to true quotes as I can recall. I received the following clearance: 'taxi Runway 10L via E4; E; hold short Runway 10R'. I read back the clearance and taxied as instructed. The next taxi clearance was: 'cross Runway 10R; turn left; taxi north on Runway 3 to 10L'. I held my position and asked the controller if he wanted me to cross runway 10R then turn left on B Taxiway to get to Runway 3 and then proceed north to 10L. The controller replied 'No'. He then said 'cross Runway 10R; take a little left; and taxi on Runway 3 for 10L'. I read back 'cross 10R then left onto 3 to taxi 10L' and proceeded to cross 10R. I did not realize the there was a Dash 8 holding short of 10R on the north side of the runway on Taxiway E. The Dash 8 had its taxi light on the entire time Ground Control and I were talking to one another; it was dark and rainy; and so I thought the Dash 8 was much farther north on Taxiway E; taxiing southbound. Once I got to the north side of 10R I realized how close the Dash 8 was and taxied around it; turned left onto B; right onto Runway 3 and finally to 10L. I knew that was not the plan in the controller's mind but I did it in order to get out of the way and onto Runway 3. I had taxied without fully understanding how the controller wanted me to transition from Taxiway E to Runway 3. Vague taxi instructions; darkness and rain and the lack of depth perception that produced; and my desire to cooperate with the controller all contributed to the mishap. Next time I do not understand a taxi clearance in its entirety I will not move my aircraft until I do. I should not have acted so hastily. I should have had less regard for maintaining traffic flow and more regard for clear communication and accurate execution of my taxi instructions.
Second reporter narrative
The aircraft continued across Runway 10R and entered Taxiway E on the north side of Runway 10R. As the aircraft approached the hold lines north of Runway 10R it appeared the flight crew may not see us and a head on collision was likely I turned on my landing and flare lights and as the aircraft came closer I flashed them on and off. The aircraft continued at a rather high rate of taxi speed across the hold lines and tracked the Taxiway E centerline to the west and intercepted Taxiway B westbound. As the aircraft passed by us I would estimate the clearance between his wingtip and my aircraft at 8 to 10 feet at the closest point. At the time of the incident it was night time with good visibility and mid level ceiling.I believe the reason the event was allowed to degenerate to this level was...the common practice of crossing aircraft on 10R on Ground Control frequency. Had the offending aircraft been on Tower frequency we would had a better situational awareness of what the aircraft was instructed to do. I was not privy to any of the communications between the other aircraft and Ground Control so the aircraft may have been given clear instructions and just got disoriented.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.