C177 pilot described a near midair collision after takeoff from cno.

Attributes
ACN	1206239
Time
Date	201409
Local Time Of Day	1201-1800
Place
Locale Reference	CNO.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cardinal 177/177RG
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	VFR
Aircraft 2
Make Model Name	Small Aircraft
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 25 Flight Crew Total 367 Flight Crew Type 25
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 400 Vertical 400

Narrative:

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.

Original NASA ASRS Text

Title: C177 pilot described a NMAC after takeoff from CNO.

Narrative: 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.

Data retrieved from NASA's ASRS site 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.