Small Aircraft
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 56; Flight Crew Total 350; Flight Crew Type 46
Communication Breakdown; Confusion; Situational Awareness
Conflict NMAC
Flight Crew Executed Go Around / Missed Approach; Flight Crew Took Evasive Action
Airport; Human Factors; Procedure
The airport was encountering heavy traffic. My student and I were remaining in a closed traffic pattern practicing landings. Multiple aircraft were reporting inbound to land on Runway 08. Having most of my experience flying at VUO; I was able to determine with the multiple calls made that there was enough distance for my student and I to continue as normal on the downwind and proceed to the base leg of the pattern without disruption. I had two inbound aircraft in sight to the north of the airport and felt a safe distance from them. However with the 5-7 close by/inbound aircraft; the CTAF frequency was congested and it was difficult for anyone to make position calls. When we turned a left base for Runway 08; Pearson Advisory called us and advised to use caution because there was another aircraft just left of us near the same altitude. The 430-GPS indicated it was to the right. I then had another aircraft in sight on base to final to the right about 500 feet horizontal and 100 feet vertical. I took the controls of the aircraft and sharply turned final for 08; began a quick descent; then made a traffic pattern call that we were on final. The other aircraft performed a go-around maneuver. From my perspective in the fast moving situation; I believe we were at the lower altitude which is why I chose to continue on final. I was unable to get the tail number of the other aircraft. I landed the plane without issue and taxied to the parking spots. No further action took place; I did not speak to the other pilot.
GA flight instructor with student reported an NMAC during approach to VUO non-towered airport requiring evasive action.  Reporter stated frequency congestion contributed to the event as it prevented pilots from making position calls.