Cardinal 177/177RG
Communication Breakdown; Situational Awareness
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
We were involved in a near mid-air collision during an instructional flight in my C177RG.We had departed westbound under excellent VMC.  After crossing the river; we flew south along the river.  After about 3 miles we commenced a left turn to the northeast in order to reenter left downwind.  We were at the pattern altitude.  As we were about to roll out of the turn my student and I both noticed out of our left window a red and white high wing airplane slide directly beneath us.  It's nose was pointed to the west/southwest but it appeared to have been traveling south to north.  I estimated the closest point of contact was 50 feet.  We had been monitoring and announcing our position on the CTAF.  Almost immediately someone came on the CTAF frequency and asked 'Cessna 177 do you hear?'.  It turned out to be the other aircraft.  The person on the radio was extremely irate and claimed we had 'cut him off'.  He said he had been flying along the river and chastised us for crossing the river.  When I could get a word in I said we hadn't seen him and I wasn't aware of any rule that precludes flying across a river.  He then went on a rant about faster/slower aircraft.  Considering that we hadn't even seen the other aircraft until after the incident; what he was saying didn't make any sense.  I mentioned again that we hadn't seen him; would keep our eyes 'peeled' (at his direction); and suggested he do the same.  At this point he got extremely abusive.  As we continued on with our approach; a third aircraft who had apparently been monitoring the conversation jumped in and the two of them had an argument about whether the incident aircraft was justified in his claims.  The third (uninvolved) aircraft was supporting us and the last we heard of the conversation was the third aircraft telling the incident pilot something to the effect of 'If you don't like it; you shouldn't be flying'.  My student and I spent a lot of time analyzing the incident later; and we couldn't figure out why we did not see the incident aircraft.  One of our objectives on that flight was local area familiarization and we were already looking outside for traffic and visual landmarks.  According to the other pilot's stated activity the incident aircraft should have been clearly visible.  We also don't know how/why the pilot was on the CTAF.  One possibility is that it was a Citabria that had been in the pattern previously.  However; based on the Citabria's previous announcements it was unlikely to be him given the location and the incident aircraft's apparent direction of flight.  Moreover since the incident aircraft was also a red and white high wing; during the brief glimpse I had; I specifically tried to identify it as such and concluded it wasn't a Citabria.  In my opinion in a situation like this; generally everybody wins or everybody loses.  That day we were all winners.  See-and-avoid in VMC is a shared responsibility.  We were all very fortunate the incident did not result in a collision and we could argue about it later.  Even though we were extremely vigilant; we didn't see the incident aircraft until afterward.  I would have liked to have known more about it's track; etc. with a view to learning how and why this happened and avoiding a similar situation in the future.  However the other pilot's abusiveness and self-righteousness precluded any such constructive discussion.  In the future I will spend even more time visually scanning for traffic and continue impressing it's criticality upon my students.  In addition I will avail myself of ADS-B IN capability (either portable or installed) in order to receive electronic alerts of conflicting traffic.
C-177 Instructor report an NMAC event during landing pattern training.