A helicopter pilot reported an NMAC with a light aircraft departing PRC.

Narrative

I was flying on my initial solo and departing Class D airspace. I was not out of the airspace yet and was flying eastbound away from the airport following Highway 89A. I climbed and was at 6;000 MSL (1;000 AGL) approximately. I was checking my instruments and making sure everything was okay. I looked up and then outside at about 2 o'clock and saw a single engine airplane at my altitude or maybe a little higher. Immediately he turned slightly to the right and climbed. I started to descend and maybe turned to the left slightly. [I descended] approximately 300 FT; PRC Tower then called and advised me that traffic was flying over top of me. I of course responded and said 'traffic in sight.' The Tower was not required [to provide] separation. However; if they notified us as we were crossing; an earlier notice would have been helpful. Mostly I should have been keeping up my scan. But; as an initial solo I was really making sure that my carburetor heat was okay along with my other instruments. Experience played a factor. The quick action by the pilots was crucial.