Cardinal 177/177RG
Flight Crew Private
Flight Crew Last 90 Days 25; Flight Crew Total 367; Flight Crew Type 25
Situational Awareness
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors
After departing CNO and climbing to around 2500 ft and being given a frequency change I input both the atis and the unicom for f70 then a few minutes later while listening for the atis I observed a small unknown airplane flying about 600 to 700 feet next to me at my 3 o-clock. I also observed that the airplane was getting closer while going the same basic direction. I tried contacting it on the unicom and also by rocking my wings; however it just kept getting closer. I then took evasive action both pulling up and climbing while moving north east to my 9 o-clock to keep away then after a few minutes the unknown plane made a sharp turn down and back towards the south west at that time I also turned south and down back on my vor course to f70.
C177 pilot described a NMAC after takeoff from CNO.