Piper Twin Piston Undifferentiated or Other Model
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 40; Flight Crew Total 2020; Flight Crew Type 45
Confusion; Situational Awareness; Communication Breakdown
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Human Factors; Chart Or Publication
While I was entering the area of Branch County Memorial Airport (KOEB) from the east; I was calling out my position on common traffic advisory frequency (CTAF); 122.70 MHz. I entered the traffic pattern with the standard 45 degree entry on downwind for runway 7. On the frequency; I heard other traffic calling out their positions for Coldwater traffic and other airports. I paid no attention to that as this frequency serves many airports in the vicinity. As I approached the 45 and getting ready to turn left base; I saw a Piper at my 8 o'clock (between me and the airport) making a left turn also toward Branch County airport. I took evasive action and called out the traffic conflict. The pilot rudely informed me he was calling out his position for Coldwater airport. On the ground; I called out on the CTAF that the AFD calls this airport Branch County and NOT Coldwater and there was a close call because they were using a non-standard name that only a local would know. I was told on the air that it is called both and they continued using the non-standard name.
A multi-engine pilot reported an NMAC occurred in the vicinity of OEB airport; in part because local practice in airport terminology (locals call the airport 'Coldwater') differs from the AFD name (Branch County).