AT NON TOWERED ARPT WITH MULTIPLE INTERSECTING RWYS; ACFT DEPARTED AS SECOND ACFT REPORTED TURN TO FINAL ON INTERSECTING RWY. LANDING ACFT MADE A GAR.

Narrative

1) HOW THE PROBLEM AROSE: VARIOUS RWYS WERE BEING USED THROUGH UNICOM COMS. THE WINDS WERE LIGHT AND VARIABLE; BUT MOSTLY FROM THE NW. RWYS 08; 26 AND 30 HAD BEEN USED FOR TKOFS AND APCHS DURING THE PRECEDING HR. AFTER DECIDING TO DEPART ON RWY 30 STRAIGHT OUT; I ANNOUNCED MY INTENTIONS; TAXIED TO THE HOLD POS AND PERFORMED MY RUN UP. WHEN I COMPLETED MY RUN UP I ANNOUNCED THAT I WAS READY TO DEPART ON RWY 30. I HEARD THE CESSNA -- I DO NOT RECALL THE N NUMBER -- CALL 'DOWNWIND' FOR RWY 04. I ANNOUNCED THAT I WAS TAKING RWY 30 FOR DEP AND BEGAN MY TKOF ROLL. 2) HOW IT WAS DISCOVERED: I WAS AIRBORNE AND CLIMBING OUT WHEN I REACHED THE INTERSECTION OF RWY 30 AND 04 AND HEARD HIM CALL 'BASE TO FINAL' AND SAW THE CESSNA OVER THE APCH END OF RWY 04 ON SHORT FINAL. HE ANNOUNCED THAT HE WAS GOING TO GAR. WE HAD EACH OTHER IN SIGHT AND HE PASSED WELL BEHIND AND BELOW ME AS I CONTINUED A STRAIGHT OUT DEP. I XMITTED AN APOLOGY SAYING THAT I DIDN'T GET HIS CALL; MEANING I DIDN'T UNDERSTAND HIS POS ON HIS DOWNWIND WHEN I TOOK THE RWY. I DID NOT HEAR A BASE CALL BEFORE I STARTED ROLLING AND INCORRECTLY ASSUMED THAT I HAD MORE TIME. HE DIDN'T RESPOND; BUT I HEARD HIM GIVING POS RPTS IN HIS DOWNWIND AND THROUGHOUT HIS GAR APCH. IT WASN'T A QUESTION OF RADIOS. 3) CONTRIBUTING FACTORS: ALTHOUGH I HEARD RWY 04 I BELIEVE MY MIND THOUGHT RWY 08. ALTHOUGH VARIOUS RWYS HAD BEEN USED IN THE HR THAT I WAS ON THE RAMP OBSERVING FLT ACTIVITIES; UP TO THIS POINT RWY 04 HAD NOT. I CERTAINLY NEVER WOULD CASUALLY TAKE OFF ON AN INTERSECTING RWY. 04) CORRECTIVE ACTIONS: THIS WAS IN NO WAY DUE TO ANY ACTIONS BY THE OTHER PLT. I SHOULD HAVE HELD IN POS AND CALLED FOR A POS RPT TO MAKE CERTAIN WHERE HE WAS IN THE PATTERN AND HOW HE INTENDED TO FLY THE PATTERN. MOREOVER; I SHOULD HAVE BETTER FAMILIARIZED MYSELF WITH THE ARPT LAYOUT AS SEVERAL RWYS HAD BEEN IN USE. THIS PROBLEM CAN BE AVOIDED BY ME TAKING THE ACTIONS I HAVE NOTED AND THIS WILL INDELIBLY PUT THOSE PROCEDURES INTO MY MIND EVERY TIME I PREPARE FOR TKOF OR PREPARE FOR LNDG. HUMAN FACTORS 1) PERCEPTION; JUDGEMENTS; DECISIONS: FAILURE TO ACCURATELY ESTABLISH POS AND PATTERN PROFILE OF AN ACFT IN THE PATTERN. SUBSEQUENT DECISION TO DEPART. 2) ACTIONS OR INACTIONS: TAKING THE RWY WITHOUT ACCURATELY ESTABLISHING POS AND PATTERN PROFILE OF THE OTHER ACFT. 3) FACTORS AFFECTING THE QUALITY OF HUMAN PERFORMANCE: INCORRECT ASSUMPTION REGARDING THE PATTERN BEING FLOWN BY THE OTHER ACFT. ON THE POSITIVE SIDE; ONCE THE SIT DEVELOPED AND BOTH PLTS WERE AWARE OF EACH OTHER; NEITHER DID ANYTHING UNPREDICTABLE THAT WOULD HAVE CAUSED THE OTHER TO TAKE FURTHER ACTION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR IS VERY DISTURBED THAT HE WAS NOT MORE FOCUSED ON THE POS OF THE OTHER ACFT. THERE WERE SEVERAL ACFT WAITING FOR TKOF BEHIND HIM. HE WAS COMPLETING HIS PRE TKOF PROCS; AND; RECEIVING NO POSITION OF A BASE LEG TURN BY THE OTHER ACFT; PRESUMED HE HAD PLENTY OF TIME FOR DEPARTURE PRIOR TO THE ACFT TURNING ONTO FINAL. HE HAS DEVELOPED NEW PROCS FOR HIMSELF ON TKOF.