Date: 201905
Local time of day: 0601-1200
Location: ORS.Airport, WA
Flight conditions: VMC
Weather elements / visibility: CAVU; 20
Light: Daylight
Aircraft: RV-8
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Final Approach
Airspace: Class G ZSE
ATC / advisory: CTAF ORS
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Air Traffic Control Fully Certified; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness
Anomaly: Conflict NMAC
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: Upon reaching ORS I overflew the field east to west at 3;000 MSL. I continued northwest bound beginning a slow descent to TPA [Traffic Pattern Altitude] and maneuvered to a position approximating left 45 for Runway 34 about 3 miles from the airport. Upon reaching TPA; I then announced intentions to enter right crosswind for RWY 34 Orcas Island. At that time; an aircraft announced from the south that it would enter straight in for Runway 34 announcing the airport name as 'Eastsound'. I made my downwind turn announcing my position and intentions for Orcas Island Runway 34. At that time; an aircraft announced its position as strait in final for Eastsound Runway 34 'traffic permitting'. I then turned base and final announcing both turns and intentions for Orcas Island Runway 34.Rolling out on final approximately 450 feet MSL; I observed Aircraft Y; approximately 35 feet to my left; 5 feet above and about 20 feet ahead. At that time I increased my separation with a gentle sidestep turn to the right maintaining visual contact. Simultaneous to my turn; someone announced over the radio that we appeared very close in proximity. I could not identify who transmitted that message. I continued my go around and queried Aircraft Y to determine where he came from and he stated he had been making announcements. I concluded my flight with traffic pattern announcements; and did not hear from Aircraft Y again nor did I query him again.I was unfamiliar with the area and did not realize that locals apparently refer to Orcas Island Airport as Eastsound. The initial call for Eastsound that came from the [color] low wing aircraft was for Runway 34; which initially caught my attention but two other airports in the area have Runway 34 designations and the thought was made a lower priority as I did not recall the names of the other 2 airports at the time.I will be more diligent in researching local behaviors; before flying in this or other congested GA areas again. I also believe that locals should use standard airport phraseology; standard recommended traffic patterns; and perhaps a flyer to that fact could be published in the terminal and an abbreviated version published on AWOS. Lastly; ADSB in and out will be installed in my aircraft before further flight.




Synopsis: Pilot reported an NMAC while attempting to land at ORS.