LAX86MA151

Factual narrative

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). Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12