Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 291; Flight Crew Total 1508; Flight Crew Type 1108
Communication Breakdown; Confusion; Situational Awareness
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Airport; Human Factors
We departed from runway XY. On CTAF; we announced departing the pattern to the south (track of 165 degrees direct to destination as cleared). An inbound Baron they were south-west of the airport entering the downwind for Runway XY. As RWY XY has a published right-hand traffic pattern; we assumed the traffic would be staying west of our position by several miles; and would be no factor. I ensured all exterior lights remained on and switched the recognition lights to 'wig-wag' mode to increase viability. Shortly after; while climbing to our clearance altitude; we made visual contact with an aircraft above us at approximately our 1-o'clock position and descending. I immediately began an evasive maneuver by descending and turning away. Once clear and resuming our climb; the Baron pilot asked who he almost hit with about 300 feet to spare. I informed him that Runway XY had a published right-hand pattern; and that his incorrect position report indicated that he should have been to the south-west of the airport and no conflict. Instead; his incorrect left-downwind entry placed him in our departure corridor. He responded by stating he was unaware that it was a published non-standard pattern for Runway XY.
A Caravan 208B flight crew departed Runway XY and turned to 165 degrees direct to their destination as cleared. When a Baron reported inbound from the southwest to the downwind for Runway XY the Caravan crew believed there would be no conflict; since Runway XY utilizes a right hand pattern. A 200 foot vertical and horizontal NMAC resulted when the Baron pilot; admittedly; was unaware of the non-standard right hand pattern and had instead proceed to the east to enter left traffic.