Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Private
Flight Crew Last 90 Days 15; Flight Crew Total 120; Flight Crew Type 0
Communication Breakdown; Confusion
Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Flight Crew Took Evasive Action
Procedure; Environment - Non Weather Related; Airport
I was in the process of aircraft shopping. I arranged for a test flight with the owner once I'd inspected the aircraft on the ramp. We agreed that he would fly; while I would monitor engine instrumentation/performance. We planned a few trips around the pattern. We taxied to Runway 34 and did run ups in preparation for departure. I asked for several additional items above and beyond the standard mag/carb heat checks. During that time; two other aircraft were talking on the CTAF which is shared with several area airports.  The PIC made the appropriate CTAF departure call and lined up on 34. We began our departure; and upon rotation; we heard a call 'XXXXX; uhh; vacating Runway 16?' We passed nearly directly overhead of the aircraft which had been preparing to depart 16; missing by about 30 feet vertically. The PIC banked to the right after a few seconds. The PIC and I were shaken; and we confirmed with one another that neither of us had heard any previous calls from the aircraft. The sun angle was such that it was difficult to see to from the 34 end of the runway to the 16 end. Additionally; both the PIC and I were distracted by the sales process and the long run-up checks. There had been traffic on both 16 and 34 earlier in the day when I had flown in. I had elected to use 34 when I landed about two hours prior. Wind conditions were calm. 34 is the preferred calm wind runway at S12.
A passenger/pilot reported passing 30 feet overhead an aircraft which entered S12 Runway 16 without CTAF communications during his takeoff from Runway 34 into an interfering sun.