Narrative:

Working controller in charge. Trainee on local control was behind; instructor started to step in. There was a cessna in the pattern; aircraft Y north east for a base entry and aircraft X checked in 8 norths east for a straight in. Trainee did not know type aircraft; I told them it was an aircraft X type. Instructor noticed the rate of speed difference; stopped the training and attempted to correct situation by changing the aircraft Y to the left runway ahead of aircraft X and when he noticed it would be close attempted to have aircraft Y turn back to the downwind to pass behind aircraft X; however; the aircraft Y was having radio difficulties and did not respond to any transmissions. I was watching through the binoculars and told the controller that aircraft Y wasn't responding to the turns he was issuing. Aircraft Y made a right 360 and aircraft X made a left 360. No traffic alert was given though he did give multiple traffic advisories. Realizing aircraft characteristics: aircraft Y was never going to beat aircraft X; and aircraft Y always uses the longer runway (25R) for landing issue a traffic alert to aircraft X when the aircraft Y lost communications; letting him know the aircraft immediately ahead was not responding and give aircraft X instructions to avoid the situation.

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Original NASA ASRS Text

Title: CIC from LVK Tower reports of NMAC that occurred while training was going on and the communication loss of radios with one of the involved aircraft. Pilot reports of close call between his aircraft and another while attempting to land.

Narrative: Working CIC. Trainee on Local Control was behind; instructor started to step in. There was a Cessna in the pattern; Aircraft Y north east for a base entry and Aircraft X checked in 8 norths east for a straight in. Trainee did not know type aircraft; I told them it was an Aircraft X type. Instructor noticed the rate of speed difference; stopped the training and attempted to correct situation by changing the Aircraft Y to the left runway ahead of Aircraft X and when he noticed it would be close attempted to have Aircraft Y turn back to the downwind to pass behind Aircraft X; however; the Aircraft Y was having radio difficulties and did not respond to any transmissions. I was watching through the binoculars and told the Controller that Aircraft Y wasn't responding to the turns he was issuing. Aircraft Y made a right 360 and Aircraft X made a left 360. No traffic alert was given though he did give multiple traffic advisories. Realizing aircraft characteristics: Aircraft Y was never going to beat Aircraft X; and Aircraft Y always uses the longer runway (25R) for landing issue a traffic alert to Aircraft X when the Aircraft Y lost communications; letting him know the aircraft immediately ahead was not responding and give Aircraft X instructions to avoid the situation.

Data retrieved from NASA's ASRS site 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.