FLC MISINTERPRETS TCASII AND CLBS TOWARD THE CONFLICT.
Synopsis
FLC MISINTERPRETS TCASII AND CLBS TOWARD THE CONFLICT.
Narrative
THE TKOF WAS MADE DIRECTLY INTO THE SUN. A 2000 FT ALT WAS ASSIGNED; AND IN SPITE OF REDUCED TKOF PWR BEING USED; THE RATE OF CLB WAS RAPID. 'OVER THE FENCE' AT 900 FT I CALLED '1000 TO GO.' THE FO CALLED 'VERT SPD 1000/FLAPS 4 DEGS/CLB PWR' ACCORDING TO STANDARD PROCS. THE TWR CALLED FOR US TO 'CHANGE TO DEP' AND CONTACT WAS INITIATED. FINALLY TCASII RA CALLED 'REDUCE CLB.' ALL OF THIS OCCURRED NEARLY SIMULTANEOUSLY. THE VERT SPD INDICATOR SHOWED A GREEN ARC BTWN 0 AND 400 FPM WITH A RED ARC ABOVE THAT. HOWEVER; THE FO (AND SO) THOUGHT THAT THE AURAL COMMAND WAS 'CLB; CLB' SO HE CONTINUED THROUGH THE 2000 FT RESTRICTION. AFTER A SECOND WARNING; I PUSHED THE STICK FORWARD AND STOPPED THE CLB AT ABOUT 2300 FT. WE NEVER SAW THE TFC IN THE GLARE OF THE SUN. SUBSEQUENTLY TCASII CALLED 'CLR OF TFC' AND DEP CLRED US TO A HIGHER ALT. THIS TCASII RA OCCURRED DURING A PERIOD OF VERY HIGH WORKLOAD; AS DO MANY OF THE RA ALERTS. NOT ONE OF US HAD TIME TO OBSERVE AND EVALUATE ALL OF THE COMMANDS AND PARAMETERS OF THE SIT. THE FO; A HIGHLY COMPETENT; ALERT PLT; FOCUSED ON THE AURAL COMMAND OF THE TCASII RA. UNFORTUNATELY; IN THE FLOOD OF ACTIVITY AND INFO HE MISUNDERSTOOD THE COMMAND. OR DID THE TCASII AURAL WARNING MALFUNCTION? THE SO; A VETERAN OF 20 YRS FLYING EXPERIENCE WITH THE MIL; ALSO THOUGHT HE HEARD A 'CLB; CLB' COMMAND. THE 2000 FT HOLD DOWN; THE PRESENCE OF TFC; AND THE REACTION OF THE TCASII IS LOGICAL. BUT UNDER THE EXISTING CONDITIONS; 3 EXPERIENCED PLTS WERE UNABLE TO AGREE ON AN INTERP OF THE TCASII. WHEN DEPARTING HIGH DENSITY ARPTS IN THE FUTURE; I WILL DOWNGRADE THE IMPORTANCE OF FLT DIRECTOR/FLAP/AND PWR COMMANDS; DEFINITELY ANTICIPATE A LOW ALT CAPTURE RATHER THAN ANTICIPATING A 'CONTINUE CLB;' AND PERHAPS EVEN TURN OFF THE RA FUNCTION OF THE TCASII. TCASII IS NOT EASY TO INTERPRET; ESPECIALLY UNDER HIGH WORKLOAD CONDITIONS. A TRAINING AID WOULD BE HELPFUL FOR PRACTICE IN RELATING TCASII AURAL AND VISUAL COMMANDS TO ACTUAL SIT.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.