Skyhawk 172/Cutlass 172
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 100; Flight Crew Total 3000; Flight Crew Type 900
Situational Awareness
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors
[I] checked both communication radios with the airport base station using the Unicom/CTAF frequency. The AAO ASOS reported winds to be 4 to 6 kts from 10 degrees magnetic; indicating that runway 36 should be used. The wind socks also indicated that runway 36 should be used.The student pilot taxied to the runway 36 run up pad and completed a pre-takeoff check. Prior to takeoff; the pilots on board visually looked for traffic and listened on the CTAF frequency. No other traffic was observed or heard. On CTAF the student pilot announced that he was taking off on runway 36; taxied onto the runway and took off. Nearing the north end of the 6000 ft runway; climbing through 400 or 500 ft AGL; [we] both observed a yellow-colored target at [our] altitude on the onboard ADS-B Flight Information System (FIS). Seconds later the conflicting aircraft; believed to be a CH2T aircraft; was observed passing below [us] and then arcing to a SSE track. No communications were ever heard from the conflicting aircraft.Note: the FIS indicates conflicts; but does not recommend a course of action.[I] believe that the CH2T was practicing Runway 18 ILS approaches to AAO. Aircraft practicing instrument approaches into AAO normally make several announcements on the CTAF frequency - particularly when the approach is opposite the active runway direction.
C172 flight instructor reported a NMAC after departing AAO.