Narrative:

I began a descent for livermore from southeast of buchanan field (ccr) along the western slope of mt. Diablo. My flight following was terminated by travis approach; so I changed frequencies to livermore tower. In descent we were moving relatively quickly; approximately 155 KIAS; and my passenger and I were discussing that the tail wind had also increased in descent yielding ground speeds in descent of 160-172 KTS. There was one other aircraft departing. On initial contact I was instructed to report a one mile right 45 for runway 25R. I received a traffic advisory for traffic departing northwest; and I believe the other aircraft was given an advisory for my aircraft. At this point we were still too far away to see anything. I ensured that all lights; including landing and taxi lights; were on to increase our visibility. Both myself and my passenger were looking for the traffic as we approached the field and we did not see it. As we were approximately 4 miles from the field; with the field in sight at 12 o'clock I thought I heard ATC tell the other aircraft to contact departure in their right hand turn. That would typically put them on the livermore one departure; still on extended upwind; and at approximately my 2 o'clock position. I scanned the area from my 12 o'clock moving clockwise again trying to spot them; and assumed they must be turning outside of my position. About this time my passenger was first to spot our traffic. He said; 'there they are;' and his voice was raised as he pointed to our 12 to 1 o'clock and just below. The aircraft was wings level on what would appear to be extended right crosswind. I immediately turned right to avoid the other aircraft and it passed off the left side below us. There was no indication the other aircraft ever saw us. The primary cause was the failure of the pilots of both aircraft to see and avoid traffic in VMC.

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Original NASA ASRS Text

Title: Entering the traffic pattern at dusk; the pilot and passenger aboard a C182 suffered an NMAC with a C172 departing the pattern.

Narrative: I began a descent for Livermore from southeast of Buchanan Field (CCR) along the western slope of Mt. Diablo. My flight following was terminated by Travis Approach; so I changed frequencies to Livermore Tower. In descent we were moving relatively quickly; approximately 155 KIAS; and my passenger and I were discussing that the tail wind had also increased in descent yielding ground speeds in descent of 160-172 KTS. There was one other aircraft departing. On initial contact I was instructed to report a one mile right 45 for Runway 25R. I received a traffic advisory for traffic departing northwest; and I believe the other aircraft was given an advisory for my aircraft. At this point we were still too far away to see anything. I ensured that all lights; including landing and taxi lights; were on to increase our visibility. Both myself and my passenger were looking for the traffic as we approached the field and we did not see it. As we were approximately 4 miles from the field; with the field in sight at 12 o'clock I thought I heard ATC tell the other aircraft to contact departure in their right hand turn. That would typically put them on the Livermore One departure; still on extended upwind; and at approximately my 2 o'clock position. I scanned the area from my 12 o'clock moving clockwise again trying to spot them; and assumed they must be turning outside of my position. About this time my passenger was first to spot our traffic. He said; 'there they are;' and his voice was raised as he pointed to our 12 to 1 o'clock and just below. The aircraft was wings level on what would appear to be extended right crosswind. I immediately turned right to avoid the other aircraft and it passed off the left side below us. There was no indication the other aircraft ever saw us. The primary cause was the failure of the pilots of both aircraft to see and avoid traffic in VMC.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.