LAX86MA151

Indianapolis ctr (ctlr-a) clrd sluff 11 (S-11), a flt of 4 ANG A-7'S, to clb to FL210. Later, ctlr-a told S-11 to chg freq (to york low sector, ctlr-b). S-11 chgd freq, but neither S-11 nor ctlr-b established rdo contact with each other until S-11 had contd into the richmond sector (ctlr c's area). Another flt, sluff 31 (S-31), canceled IFR clnc with ctlr-c; however, ctlr-c (a developmental ctlr) bcm confused with the similar call signs & inadvertently entered a cancellation note on the computer strip for S-11; his instructor did not note the error. The strip was handed to the d-side ctlr, who questioned the notation, but entered a cancellation message in the computer, thus replacing the full data blk for S-11 with a limited data blk. Svrl min later, S-11 converged with a Boeing 727 (twa flt 489) that had been clrd to clb to FL230. Subsequently, the flts passed w/i an estimated 500' vertically & 200' laterally of each other. The flt leader of sluff 11 was on a check flt & was being evaluated by a stan/eval instructor plt (sluff 12).

Indianapolis ctr (ctlr-a) clrd sluff 11 (S-11), a flt of 4 ANG A-7'S, to clb to FL210. Later, ctlr-a told S-11 to chg freq (to york low sector, ctlr-b). S-11 chgd freq, but neither S-11 nor ctlr-b established rdo contact with each other until S-11 had contd into the richmond sector (ctlr c's area). Another flt, sluff 31 (S-31), canceled IFR clnc with ctlr-c; however, ctlr-c (a developmental ctlr) bcm confused with the similar call signs & inadvertently entered a cancellation note on the computor strip for S-11; his instructor did not note the error. The strip was handed to the d-side ctlr, who questioned the notation, but entered a cancellation message in the computer, thus replacing the full data blk for S-11 with a limited data blk. Svrl min later, S-11 converged with a Boeing 727 (twa flt 489) that had been clrd to clb to FL230. Subsequently, the flts passed w/i an estimated 500' vertically & 200' laterally of each other. The flt leader of sluff 11 was on a check flt & was being evaluated by a stan/eval instructor plt (sluff 12).