Narrative:

Arrived dpa to have maintenance work performed. 1 item was to install loaner gyrocompass box since mine was acting erratically. Checked loaner on ground and worked satisfactorily. Assigned runway 10 given left turn to the northeast (to home base at ugn). Incidentally this was the same runway that was assigned upon arriving. After several mins having left dpa, in fact never having changed radio frequency, my gyro went berserk, spinning continuously, finally coming to rest and remaining fixed on a northerly heading. Attempting to unlock the gyro made many turns while holding fast slave switch to no avail. Thus aim was to return to dpa to exchange this erratic box for mine. After making so many turns I was not quite certain as to my exact location from dpa. Nevertheless, I called epa tower to alert them that I was returning to field but my position was questionable. After a short time I called (twice) that I was north on a left downwind for runway 10. I was cleared to land. No further comments were made by the tower. While reinstalling and checking my gyro an individual who claimed he was a flight instrument arrived at the shop and criticized my technique by stating that there was a near miss with his aircraft. At no time had I seen any aircraft from my aircraft nor was any tower announcement made of any aircraft in my vicinity. I do not know any distances or if the other aircraft took evasive action since I never saw one.

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Original NASA ASRS Text

Title: AFTER LNDG REPORTER WAS ADVISED BY ANOTHER PLT THAT A NMAC HAD OCCURRED INVOLVING REPORTER ACFT.

Narrative: ARRIVED DPA TO HAVE MAINT WORK PERFORMED. 1 ITEM WAS TO INSTALL LOANER GYROCOMPASS BOX SINCE MINE WAS ACTING ERRATICALLY. CHKED LOANER ON GND AND WORKED SATISFACTORILY. ASSIGNED RWY 10 GIVEN LEFT TURN TO THE NE (TO HOME BASE AT UGN). INCIDENTALLY THIS WAS THE SAME RWY THAT WAS ASSIGNED UPON ARRIVING. AFTER SEVERAL MINS HAVING LEFT DPA, IN FACT NEVER HAVING CHANGED RADIO FREQ, MY GYRO WENT BERSERK, SPINNING CONTINUOUSLY, FINALLY COMING TO REST AND REMAINING FIXED ON A NORTHERLY HDG. ATTEMPTING TO UNLOCK THE GYRO MADE MANY TURNS WHILE HOLDING FAST SLAVE SWITCH TO NO AVAIL. THUS AIM WAS TO RETURN TO DPA TO EXCHANGE THIS ERRATIC BOX FOR MINE. AFTER MAKING SO MANY TURNS I WAS NOT QUITE CERTAIN AS TO MY EXACT LOCATION FROM DPA. NEVERTHELESS, I CALLED EPA TWR TO ALERT THEM THAT I WAS RETURNING TO FIELD BUT MY POS WAS QUESTIONABLE. AFTER A SHORT TIME I CALLED (TWICE) THAT I WAS N ON A LEFT DOWNWIND FOR RWY 10. I WAS CLRED TO LAND. NO FURTHER COMMENTS WERE MADE BY THE TWR. WHILE REINSTALLING AND CHKING MY GYRO AN INDIVIDUAL WHO CLAIMED HE WAS A FLT INSTR ARRIVED AT THE SHOP AND CRITICIZED MY TECHNIQUE BY STATING THAT THERE WAS A NEAR MISS WITH HIS ACFT. AT NO TIME HAD I SEEN ANY ACFT FROM MY ACFT NOR WAS ANY TWR ANNOUNCEMENT MADE OF ANY ACFT IN MY VICINITY. I DO NOT KNOW ANY DISTANCES OR IF THE OTHER ACFT TOOK EVASIVE ACTION SINCE I NEVER SAW ONE.

Data retrieved from NASA's ASRS site as of August 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.