Narrative:

As I was approaching bdn I announced my intentions to cross over the airfield from the east and enter a right downwind for runway 16 as the winds were calm. At approximately less than 10 miles out; traffic on frequency asked if anyone was using runway 34; someone replied the calm wind runway was runway 16; then someone mentioned that gliders were using runway 34. At this point the airport was 5 miles or less from my present position and decided to inform traffic that I was switching to runway 34 (since others were using runway 34); planning to enter on a left downwind. I misinterpreted my position from the moving map on the ipad and mistakenly entered a right downwind for runway 34 instead of a left downwind. As I turned right downwind runway 34; I recognized something didn't look right; I maintained altitude of 5;000-5;200 feet MSL and made a radio call but believe to have announced an erroneous position; I saw a cessna on left base runway 34 pass approximately 500 feet below. Another aircraft on left downwind said he had a visual on me but didn't know what I was doing. I apologize and said I wasn't familiar with the area; and that was going to intercept the 45 left downwind runway 34. I continued heading west and then entered the 45 left downwind runway 34; this time being on the correct pattern side; and continued.this was my first time at bdn; and although I had done my homework and knew runway 16 was right pattern and runway 34 left pattern; I only planned for runway 16 since it is the designated calm wind runway and the winds were calling light or calm. I should have planned also for runway 34; for an instance like this or I also could have overflown the airfield and given myself time to re-plan my entry and comeback; especially since my entry plan had to change pretty close to the destination once I knew other aircraft were using runway 34. I also could have use other resources such as my heading indicator and double check my position in relation to the runway and proper traffic pattern.

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Original NASA ASRS Text

Title: PC-12 pilot reported they made an incorrect pattern entry to a non-towered airport resulting in a near miss.

Narrative: As I was approaching BDN I announced my intentions to cross over the airfield from the east and enter a right downwind for Runway 16 as the winds were calm. At approximately less than 10 miles out; traffic on frequency asked if anyone was using Runway 34; someone replied the calm wind runway was Runway 16; then someone mentioned that gliders were using Runway 34. At this point the airport was 5 miles or less from my present position and decided to inform traffic that I was switching to Runway 34 (since others were using Runway 34); planning to enter on a left downwind. I misinterpreted my position from the moving map on the iPad and mistakenly entered a right downwind for Runway 34 instead of a left downwind. As I turned right downwind Runway 34; I recognized something didn't look right; I maintained altitude of 5;000-5;200 feet MSL and made a radio call but believe to have announced an erroneous position; I saw a Cessna on left base Runway 34 pass approximately 500 feet below. Another aircraft on left downwind said he had a visual on me but didn't know what I was doing. I apologize and said I wasn't familiar with the area; and that was going to intercept the 45 left downwind Runway 34. I continued heading west and then entered the 45 left downwind Runway 34; this time being on the correct pattern side; and continued.This was my first time at BDN; and although I had done my homework and knew Runway 16 was right pattern and Runway 34 left pattern; I only planned for Runway 16 since it is the designated calm wind Runway and the winds were calling light or calm. I should have planned also for Runway 34; for an instance like this or I also could have overflown the airfield and given myself time to re-plan my entry and comeback; especially since my entry plan had to change pretty close to the destination once I knew other aircraft were using Runway 34. I also could have use other resources such as my heading indicator and double check my position in relation to the Runway and proper traffic pattern.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.