STICK SHAKER ACTIVATION ON MD-11 DURING LEVEL OFF AND IN A 25 DEG BANK DURING RADAR VECTORING ON APCH CTL.

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DURING ARR INTO OSAKA; JAPAN; STICK SHAKER ACTIVATION OCCURRED DURING INTERMEDIATE LEVEL OFF. AUTOPLT AND AUTOTHROTTLES WERE OPERATIVE AND ON. ASSIGNED SPD WAS 210 KTS. FMS GENERATES A MINIMUM SPD CALLED A 'FOOT;' AND THIS 'FOOT' IS INDICATED ON THE AIRSPD INDICATOR ON THE 'PRIMARY FLT DISPLAY.' COMPANY POLICY IS THAT 'FOOT' PLUS 5 KTS IS MINIMUM MANEUVERING SPD. THE 'FOOT' INDICATED 203 KTS; SO 210 KTS WAS 2 KTS ABOVE MINIMUM MANEUVERING SPD. AS THE ACFT APCHED THE 8000 FT ASSIGNED ALT; WE WERE ASSIGNED A NEW HDG. I TOOK MY L HAND FROM ITS 'MONITORING' POS ON THE THROTTLES TO SELECT THE NEW HDG. THE ACFT ROLLED TO APPROX 25 DEGS OF BANK. I RECALL BEING SURPRISED THAT THE BANK LIMITER (ALSO IN AUTO) HAD NOT PREVENTED A 25 DEG BANK AT THAT AIRSPD. SIMULTANEOUSLY THE ACFT LEVELED AT 8000 FT; AND AS MY HAND RETURNED TO THE THROTTLES; I NOTICED ONLY A SMALL INCREASE FROM IDLE; AND SLOW FORWARD MOVEMENT. I THEN RETURNED MY ATTN TO THE PFD AND NOTICED THE AIRSPD DROPPING RAPIDLY THROUGH THE FOOT. I OVERRODE THE THROTTLES WITH A MODERATE FORCE; ANTICIPATING ENG SPOOL-UP. MY INPUT WAS INSUFFICIENT TO PREVENT FURTHER DELAY IN AIRSPD. AS I WAS INCREASING THRUST; THE AIRSPD DROPPED TO ABOUT 192 KTS; AND STICK SHAKER ACTIVATION OCCURRED. I ROLLED LEVEL; AND PERFORMED A STALL RECOVERY WHILE THE CAPT EXTENDED THE SLATS. ANALYSIS: AUTOTHROTTLE RESPONSE WAS MUCH TOO GRADUAL. SINCE THEY WERE OPERATIVE; DOES THE SOFTWARE NOT RESPOND RAPIDLY ENOUGH IN THIS SIT? 'FOOT' PLUS 5 KTS MAY NOT BE AN ADEQUATE MANEUVERING SPD IN ALL SITS. HUMAN REACTION TIME SHOULD BE CONSIDERED; AS WELL AS OTHER FACTORS. AUTOBANK LIMITS NEED TO BE REVIEWED. I DON'T THINK THE SOFTWARE WORKS THE WAY THE MANUAL SAYS IT DOES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CALLBACK TO RPTR REVEALED THAT HE HAS SUBMITTED THIS RPT TO UNION AND WAS IN THE PROCESS OF DETAILING A RPT TO HIS COMPANY. HE INDICATED THAT THERE WERE NO PREVIOUS EVENTS OF THIS NATURE; AT LEAST TO HIS KNOWLEDGE; WITH THE MD- 11. HE STATED THAT HE HAD THOUGHT THAT THE BANK ANGLE LIMITER WOULD NOT ALLOW 25 DEGS OF BANK AT V REF MINIMUM MANEUVERING PLUS 5 KTS; THINKING THAT IT WOULD BE BASED ON AIRSPD AND CONFIGN AT THAT ALT. THE PLTS OPERATING MANUAL CONFIRMS THAT BANK IS DEPENDENT UPON AIRSPD; STALL AND BUFFET MARGINS. HE REPLIED; WHEN QUESTIONED; THAT YES; THE FLAPS AND SLATS WERE RETRACTED FOR FUEL SAVINGS CONSIDERATIONS. THE AUTO THRUST RESPONSE WHEN THE ACFT LEVELED OFF WAS TOO SLOW AND THE FO STATED THAT HIS ACTION OF APPLYING SOME THRUST WAS TOO SLOW AS HE SAW THE THROTTLES MOVE BUT EXPECTED A FASTER MOVEMENT THAN HE GOT. THE THROTTLES TEND TO BE SLUGGISH FROM IDLE POS WHEN TRANSITIONING FROM SPD ON PITCH CTL TO SPD ON THRUST CTL. RPTR SUMMED UP HIS CONCERNS WITH: THE SPD OF 'FOOT' PLUS 5 IS TOO LOW. ('FOOT' IS THE MINIMUM MANEUVER SPD FOR CONFIGN). A POSSIBLE PROB WITH THE SOFTWARE OF THE ATS SYS. BETTER EDUCATION AND INFO FOR THE FLCS ON THE AUTO BANK ANGLE LIMITS.