Narrative:

I was approaching the colby airport from the south, entering the downwind leg for runway 17, in my thrush ag-aircraft with no aviation radios. After I turned final approach about 3/4 mi from the end of the runway, I realized, after seeing a shadow on the ground, there may be another aircraft on final that I had not seen. I looked behind me and to the right and spotted the king air that probably had already been on final prior to me turning final. Contributing factors to this situation were lack of observation of the final approach path, letting other thoughts of business take precedence over flying. To resolve future problems, I will be installing aircraft radios in these ag-aircraft and keeping my mind on flying safely (vigilance). As to the outcome both aircraft made gars.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN AGRICULTURE PLT WITH NO RADIO, NOTICES ANOTHER ACFT ON FINAL AT AN UNCTLED ARPT. BOTH ACFT EXECUTE A GAR.

Narrative: I WAS APCHING THE COLBY ARPT FROM THE S, ENTERING THE DOWNWIND LEG FOR RWY 17, IN MY THRUSH AG-ACFT WITH NO AVIATION RADIOS. AFTER I TURNED FINAL APCH ABOUT 3/4 MI FROM THE END OF THE RWY, I REALIZED, AFTER SEEING A SHADOW ON THE GND, THERE MAY BE ANOTHER ACFT ON FINAL THAT I HAD NOT SEEN. I LOOKED BEHIND ME AND TO THE R AND SPOTTED THE KING AIR THAT PROBABLY HAD ALREADY BEEN ON FINAL PRIOR TO ME TURNING FINAL. CONTRIBUTING FACTORS TO THIS SIT WERE LACK OF OBSERVATION OF THE FINAL APCH PATH, LETTING OTHER THOUGHTS OF BUSINESS TAKE PRECEDENCE OVER FLYING. TO RESOLVE FUTURE PROBS, I WILL BE INSTALLING ACFT RADIOS IN THESE AG-ACFT AND KEEPING MY MIND ON FLYING SAFELY (VIGILANCE). AS TO THE OUTCOME BOTH ACFT MADE GARS.

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.