ACR X AND Y NON ADHERENCE TO ATC CLRNC. ACR X TCASII TA RA DSND; ACY Y TCASII RA CLB TO OCCUPIED ALT HAD NMAC LTSS. EVASIVE ACTION TAKEN. NON ADHERENCE TO ATC INSTRUCTION.
Synopsis
ACR X AND Y NON ADHERENCE TO ATC CLRNC. ACR X TCASII TA RA DSND; ACY Y TCASII RA CLB TO OCCUPIED ALT HAD NMAC LTSS. EVASIVE ACTION TAKEN. NON ADHERENCE TO ATC INSTRUCTION.
Narrative
ACR X WAS INBOUND TO SEATAC ON THE OLYMPIA 1 STAR; LEVEL AT 10000 FT (UNDER MY CTL). ACR Y DEPARTED FOR SFO ON THE ELLMA DEP SID; CLBING TO ASSIGNED ALT OF 9000 FT. APPROX 14 MI SW OF SEA; I ISSUED TFC TO ACR X; THAT THE ACR Y WAS LEVELING 9000 FT. ACR X RPTED AFTER A FEW SECONDS THAT THEY WERE DSNDING. I AGAIN TOLD ACR X TO MAINTAIN 10000 FT. ACR X RESPONDED; 'OK; WE'VE GOT AN ALERT SAYING GO DOWN.' SIMULTANEOUSLY; ACR Y WAS GETTING AN ALERT TO CLB. THEY BOTH FOLLOWED THE TCASII AND ALMOST COLLIDED. LATER; ACR X PLT INDICATED HIS TCASII WAS SHOWING 0 SEPARATION. THEY PASSED IN THE CLOUDS WITHOUT SEEING EACH OTHER. WHEN PLTS START TAKING EVASIVE ACTION; OUR EQUIP CANNOT UPDATE QUICK ENOUGH FOR THE CTLR TO HELP. BOTH ACFT WERE ISSUED TFC AS PRESCRIBED BY OUR HANDBOOK (MERGING TARGET PROCS). COMPANY DIRECTIVES; I'M TOLD; DICTATE THAT PLTS MUST RESPOND/FOLLOW THE TCASII ALERT ADVISORIES. SUPPLEMENTAL INFO FROM ACN 224982: ACR Y DEPARTED SEA SWBOUND CLBING TO 9000 FT; WAS ISSUED TFC TO HIS 11 O'CLOCK; LEVEL AT 10000 FT. ACR Y WAS TCASII ALERTED TO THE TFC AT 10000 FT. THE ALERT ADVISED PLT TO CLB. ACR Y CLBED THROUGH TFC. TFC FOR ACR Y WAS ACR X WITH TCASII ALSO; ACR X WAS NEBOUND. THIS EVENT WAS A RESULT OF PRE-IMPLEMENTATION OF THE TCASII FOR POLITICAL REASONS AND COMPANY POLICY DICTATES USE OF THE TCASII. PLTS CAN NOW DISREGARD ATC INSTRUCTIONS BASED ON TCASII ALERTS -- EVEN IF THE CTLR HAS ISSUED TFC TO THAT ACFT AND HAS APPLIED THE CORRECT SEPARATION! SUPPLEMENTAL INFO FROM ACN 224912: ACR X RECEIVED A TA ANNUNCIATION FOLLOWED BY IMMEDIATE RA. ANNUNCIATION WAS DSND XING DSND. WE IMMEDIATELY PUSHED OVER FOLLOWING RA TO 2000- 2500 FPM DSCNT. INTRUDER WAS SHOWING 1200-1230; 800 FT BELOW; CLBING. I INSTRUCTED FO TO ADVISE ATC OF DSCNT. ATC ADVISED INTRUDER WAS ACR WHO WAS ON A DIFFERENT FREQ (128.3?) AND THAT HE WAS LEVELING OFF. CTLR ADVISED US TO LEVEL AND THEN CLB. BOTH ACFT PASSED TO EACH OTHER'S R ON THE SAME ALT; APPROX 9700 FT. LOWEST ALT ACHIEVED WAS 9650 FT. DURING EVENT THINGS GOT CONFUSING. RA CALLED FOR DSCNT AND THEN INCREASED DSCNT. ATC IS CALLING FOR A LEVEL OFF FOLLOWED BY IMMEDIATE CLB. RA SHOWS INTRUDER AT 00 ALT. THE TCASII SYS REQUIRES BOTH ACFT TO COMPLY WITH RA. IF ONE DOES NOT COMPLY; THE SOLUTION WILL NOT PROVIDE A SAFE SEPARATION. PROCS NEED TO BE DEVELOPED TO ENSURE COMPLIANCE BY CREWS IN THE EVENT OF RA. ATC'S ROLE IN THE SOLUTION OF CONFLICT NEEDS TO BE DEFINED WHEN USING THIS SYS. ON LNDG; THE ATC SUPVR INDICATED THE ACR Y WAS CLRED TO 9000 FT.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.