Narrative:

Approaching gge from the northeast and using ground smoke to determine wind direction, wind appeared to be a light crosswind slightly favoring runway 5. Captain elected to make a straight in landing to runway 23. Copilot requested airport advisory, got no response, then announced our position and intentions in the blind. On a 3/4 mi final for runway 23, PF noticed an aircraft near the approach end of runway 23. Due to its proximity to the end of the runway and its apparent slow speed we assumed it was landing and preparing to exit the runway. On about a 1/2 mi final we realized the aircraft was climbing out and we were on a collision course. We sidestepped right and entered a left downwind for runway 5. The government helicopter made a 180 degree right turn and exited the pattern on an upwind leg. On downwind captain then noticed the wrong unicom frequency had been selected earlier. Although the frequency error was a contributing factor, if we had flown a standard pattern this incident would probably have been avoided anyway.

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Original NASA ASRS Text

Title: POTENTIAL CONFLICT AT A NON TWR ARPT UNICOM BTWN CPR JET AND ROTARY WINGED TFC IN AN OPPOSITE DIRECTION TFC SITUATION.

Narrative: APCHING GGE FROM THE NE AND USING GND SMOKE TO DETERMINE WIND DIRECTION, WIND APPEARED TO BE A LIGHT XWIND SLIGHTLY FAVORING RWY 5. CAPT ELECTED TO MAKE A STRAIGHT IN LNDG TO RWY 23. COPLT REQUESTED ARPT ADVISORY, GOT NO RESPONSE, THEN ANNOUNCED OUR POS AND INTENTIONS IN THE BLIND. ON A 3/4 MI FINAL FOR RWY 23, PF NOTICED AN ACFT NEAR THE APCH END OF RWY 23. DUE TO ITS PROX TO THE END OF THE RWY AND ITS APPARENT SLOW SPD WE ASSUMED IT WAS LNDG AND PREPARING TO EXIT THE RWY. ON ABOUT A 1/2 MI FINAL WE REALIZED THE ACFT WAS CLBING OUT AND WE WERE ON A COLLISION COURSE. WE SIDESTEPPED R AND ENTERED A L DOWNWIND FOR RWY 5. THE GOV HELI MADE A 180 DEG R TURN AND EXITED THE PATTERN ON AN UPWIND LEG. ON DOWNWIND CAPT THEN NOTICED THE WRONG UNICOM FREQ HAD BEEN SELECTED EARLIER. ALTHOUGH THE FREQ ERROR WAS A CONTRIBUTING FACTOR, IF WE HAD FLOWN A STANDARD PATTERN THIS INCIDENT WOULD PROBABLY HAVE BEEN AVOIDED ANYWAY.

Data retrieved from NASA's ASRS site as of July 2007 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.