Narrative:

Local controller was working combined position in tower. One cessna was in touch-and-go training; left traffic for runway 24. The air carrier reported northeast on the right base and was told to continue. Another air carrier was released runway 24 with a controled departure time. The cessna was on downwind and told to make a right 360 degree turn. This is normal practice to keep training aircraft close in and due to hazy conditions; the departing air carrier was switched to departure off the departure end and the arriving air carrier was cleared to land as he turned a 4 mi final. The controller was delivering a clearance to another on the ground when the air carrier asked what the C172 was doing. The controller then gave traffic to the air carrier and questioned the cessna. The cessna had made the 360 degree turn back to downwind; but immediately started a base turn toward the air carrier. The cessna was told to turn to re-enter downwind. The air carrier; being uncomfortable with the situation; decided to go around to the right to re-enter final. All landed with no further problems. Factors: controller performing multiple tasks caused attention to be diverted for seconds -- enough to miss the cessna turning base. Instructions on who to follow were not given. The cessna turned base too early when exiting the 360 degree maneuver. Training led to lack of awareness of air carrier on final. Air carrier pilot's alertness averted worse situation.

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Original NASA ASRS Text

Title: ILM CTLR FAILS TO OBSERVE ACFT MANEUVERS IN PATTERN RESULTING IN ACR GAR.

Narrative: LCL CTLR WAS WORKING COMBINED POS IN TWR. ONE CESSNA WAS IN TOUCH-AND-GO TRAINING; L TFC FOR RWY 24. THE ACR RPTED NE ON THE R BASE AND WAS TOLD TO CONTINUE. ANOTHER ACR WAS RELEASED RWY 24 WITH A CTLED DEP TIME. THE CESSNA WAS ON DOWNWIND AND TOLD TO MAKE A R 360 DEG TURN. THIS IS NORMAL PRACTICE TO KEEP TRAINING ACFT CLOSE IN AND DUE TO HAZY CONDITIONS; THE DEPARTING ACR WAS SWITCHED TO DEP OFF THE DEP END AND THE ARRIVING ACR WAS CLRED TO LAND AS HE TURNED A 4 MI FINAL. THE CTLR WAS DELIVERING A CLRNC TO ANOTHER ON THE GND WHEN THE ACR ASKED WHAT THE C172 WAS DOING. THE CTLR THEN GAVE TFC TO THE ACR AND QUESTIONED THE CESSNA. THE CESSNA HAD MADE THE 360 DEG TURN BACK TO DOWNWIND; BUT IMMEDIATELY STARTED A BASE TURN TOWARD THE ACR. THE CESSNA WAS TOLD TO TURN TO RE-ENTER DOWNWIND. THE ACR; BEING UNCOMFORTABLE WITH THE SIT; DECIDED TO GO AROUND TO THE R TO RE-ENTER FINAL. ALL LANDED WITH NO FURTHER PROBS. FACTORS: CTLR PERFORMING MULTIPLE TASKS CAUSED ATTN TO BE DIVERTED FOR SECONDS -- ENOUGH TO MISS THE CESSNA TURNING BASE. INSTRUCTIONS ON WHO TO FOLLOW WERE NOT GIVEN. THE CESSNA TURNED BASE TOO EARLY WHEN EXITING THE 360 DEG MANEUVER. TRAINING LED TO LACK OF AWARENESS OF ACR ON FINAL. ACR PLT'S ALERTNESS AVERTED WORSE SIT.

Data retrieved from NASA's ASRS site as of January 2009 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.