FDAI logo   ::  Site Map  ::   
Home  |  About This Website  |  Contact Us
About This Website » ASRS Incident Report Analysis » Incidents related to Issue

Incidents related to Issue 6 incidents related to this issue.

Issue: company automation policies and procedures may be inappropriate or inadequate (Issue #166)
Description: Company policies and procedures for the use of automation may be inappropriate or inadequate in some circumstances, possibly compelling pilots to use automation when they prefer not to and/or leading to pilot confusion or frustration.

  1.  
  2. Accession Number: 373476
    Synopsis: A B757 ACR FLC CLBS ABOVE THEIR ASSIGNED ALT WHEN THEY ARE OVERWHELMED BY THE AUTOMATION WORKLOAD INVOLVED IN A LOW ALT LEVELOFF WHILE CHANGING THE ACFT'S CONFIGN AND MAINTAINING ITS SPD, WITHIN ITS CONFIGN-BASED, LIMITATIONS.
    Narrative: THE PROB AROSE ON DEP FROM LAX. OUR CLRNC CALLED FOR A DEP HDG OF 250 DEGS AND A CLB TO 2000 FT. AFTER RAISING THE GEAR AND MAKING THE INITIAL PITCH REDUCTION I REDUCED THE THRUST TO THE CLB SETTING AND STARTED RAISING THE FLAPS. 2000 FT ARRIVES VERY QUICKLY ON THIS DEP SO AS WE CLBED THROUGH ABOUT 1500 FT I REDUCED THE PITCH EVEN MORE SO AS TO NOT OVERSHOOT THE ALT. SHORTLY THEREAFTER I REALIZED THAT THE AIRSPD WAS BUILDING RAPIDLY AND WAS IN FACT ABOUT TO EXCEED THE FLAPS EXTEND SPD. THE FLAPS HAD ALREADY BEEN SELECTED TO THE UP POS BUT WERE STILL IN THE PROCESS OF MOVING UP, SO, TO NOT EXCEED FLAPS EXTEND SPD I DID WHAT I NORMALLY DO -- I INCREASED THE PITCH. BUT IN DOING SO I COMPLETELY FORGOT ABOUT MY PROXIMITY TO 2000 FT. THE FO YELLED A WARNING AS WE WENT THROUGH 2000 FT AND I PULLED THE THRUST TO IDLE AND PITCHED OVER TO REGAIN 2000 FT. THE HIGHEST ALT I SAW WAS ABOUT 2350 FT. HOW DID THIS HAPPEN? WELL, THIS IS A GLASS COCKPIT ACFT AND THIS IS ANOTHER EXAMPLE OF THE CONFLICT BTWN REQUIRED MANEUVERS AND SOPS IN SUCH ACFT. IN THIS CASE THE MANEUVER TO LEVEL AT 2000 FT AND THE SOP TO FLY THE ACFT USING AUTOMATION SUCH AS AUTOTHROTTLES. THE AUTOTHROTTLES WOULD HAVE REDUCED THRUST TO MAINTAIN THE AIRSPD HAD THE AUTO FLT SYS CAPTURED THE ALT, BUT SINCE I HAD DECREASED THE PITCH SOMEWHAT SO AS TO NOT APCH 2000 FT TOO RAPIDLY THE SYS DELAYED THE ALT CAPTURE WHICH IN TURN LEFT THE THROTTLES IN THE CLB THRUST MODE WHICH IN TURN FORCED THE AIRSPD TO BUILD RAPIDLY. CONTRIBUTING FACTORS INCLUDE THE ALT ASSIGNMENT OF 2000 FT. ALL HIGH PERFORMANCE ACFT SHOULD HAVE AN INITIAL ALT ASSIGNMENT OF AT LEAST 5000 FT ABOVE THE ARPT OR HIGHER. ANOTHER FACTOR IS THE DISTR OF THE FREQ CHANGE AND RADIO CALLS REQUIRED AT THIS STAGE OF FLT.

  3.  
  4. Accession Number: 380520
    Synopsis: B737-300 ACFT ON STAR ARR. RPTR CAPT HAD FMC SET FOR NEXT DSCNT BUT WHEN DEVIATING AROUND WX IN HDG SELECT THE FMC CHANGED MODES TO LEVEL CHANGE AND COMMENCED DSCNT. RPTR CAUGHT IT AFTER 400 FT AND RETURNED TO ALT.
    Narrative: ON THE COAST 2 STAR INTO IAH, I WAS LEVEL AT 10000 FT AND 2 MI NW OF MACED INTXN. THE COAST 2 IS AN FMC ARR. I HAD THE AUTOPLT FLYING IN LNAV AND VNAV WITH 6000 FT SET IN THE MCP ALT WINDOW. THE WX WAS BROKEN CLOUD COVERAGE WITH NUMEROUS CUMULO NIMBUS ON THE ARR COURSE. I REQUESTED PERMISSION TO DEVIATE AROUND THE BUILDUPS AND PERMISSION WAS GRANTED. WHEN I SELECTED HDG SELECT TO GO L OF COURSE, THE FLT DIRECTOR COMMAND BARS WENT OUT OF VIEW AND THE MODE ANNUNCIATOR SHOWED CTL WHEEL STEERING PITCH. THIS CONFUSED ME AND I TRIED TO ENGAGE A PITCH MODE TO GET THE FLT DIRECTOR BACK AS I WENT AROUND THE BUILDUPS. AT THIS TIME, I SAW THE 6000 FT IN THE MCP WINDOW AND SELECTED LEVEL CHANGE. THE FLT DIRECTOR RETURNED AND THE ACFT STARTED TO DSND. SINCE THERE IS AN ALT RESTR AT MACED OF 10000 FT, I DISENGAGED THE AUTOPLT AND RETURNED THE ACFT TO 10000 FT. IT HAD DSNDED TO ABOUT 9600 FT. IT IS AN APPROVED PROC IN OUR OPS MANUAL TO PUT IN THE CORRECT ALT ON AN FMC ARR (IN THIS CASE 6000 FT), HOWEVER, THIS PRACTICE CAN GET PLTS IN TROUBLE IF THEY NEED TO DEVIATE FOR WX AND REFER TO MCP ALT FOR THE ALT THEY ARE CLRED TO, WHICH IS WHAT I DO ROUTINELY. IN THE FUTURE, I WILL NEVER PUT IN THE LOWER ALT UNTIL I AM AT THE DSCNT POINT FOR THE NEXT ALT.

  5.  
  6. Accession Number: 385162
    Synopsis: ATR72 FLC IS ON VISUAL APCH TO RWY 5 WITH TFC TURNING BASE TO FINAL FOR RWY 23 WHEN THEY RECEIVE A GPWS ALERT. BECAUSE THEY CAN SEE THEY ARE ON GS AND NO TERRAIN PROB, THEY DECIDE TO CONTINUE APCH RATHER THAN GO MISSED DUE TO OPPOSITE DIRECTION TFC.
    Narrative: WE WERE CLRED FOR A VISUAL APCH TO RWY 5 INTO TRI-CITIES AT 12 MI SW. A GULFSTREAM WAS ON A CTLED DOWNWIND FOR A VISUAL TO RWY 23. BOTH OF US WERE ON TWR FREQ. WE WERE LINED UP ON THE LOC FOR RWY 23 USING THE VASI FOR RWY 5 FOR VERT GUIDANCE. AT APPROX 0.8 TO 1.0 MI FROM THE ARPT THE VASI SHOWED US SLIGHTLY ABOVE THE GS. THE RADAR ALTIMETER SHOWED US APPROX 700 FT. AT THIS TIME WE HAD FULL LNDG CONFIGN. ALSO, AT THIS POINT WE RECEIVED THE GPWS 'TERRAIN, TERRAIN' 'PULL UP, PULL UP.' THE GULFSTREAM WAS APPROX 3 MI OUT ON BASE TO FINAL FOR RWY 23. INSTEAD OF GOING AROUND AND RISKING A POTENTIAL MIDAIR CONFLICT WE RESOLVED UPON OBVIOUS INST AND VISUAL CUES WE SHOULD CONTINUE A NORMAL APCH AND LNDG. WE LANDED WITHIN THE TOUCHDOWN ZONE NORMALLY WITHOUT ANY ABRUPT CORRECTIVE ACTION. WE INFORMED THE TWR OF THE ALERT. THE COORDINATED DECISIONS BTWN THE PIC AND MYSELF WERE MADE FOR SAFETY CONSIDERATIONS EVEN THOUGH THE COMPANY PROC IS TO OBEY ALL GPWS AT NIGHT, NO MATTER IF ERRONEOUS OR VISUAL CUES COULD PERMIT OTHERWISE. I BELIEVE PROCEDURALLY AUTH SHOULD BE GIVEN TO THE FLC IN VMC CONDITIONS (INCLUDING NIGHT) TO PREVENT OBVIOUS ERRONEOUS GPWS ALERTS TO BE DISREGARDED, ESPECIALLY IF SAFETY OF FLT IS A SERIOUS CONSIDERATION.

  7.  
  8. Accession Number: 386850
    Synopsis: CAPT OF A B757 OVERSHOT DSCNT ASSIGNED ALT DUE TO A MISUNDERSTANDING OF THE CORRECT ALT. HOWEVER, AFTER FO REQUESTED CLARIFICATION FROM ATC, THEY WERE RECLRED TO STAY AT THAT ALT.
    Narrative: ON DSCNT INTO MEM PASSING 9200 FT FOR 8000 FT ON THE GILMORE STAR, APCH TOLD US TO LEVEL AT 9000 FT AND MAKE A L 360 DEG TURN TO REJOIN THE ARR. I ACKNOWLEDGED THE NEW CLRNC AND OBSERVED THE CAPT SLEWING THE HDG TO THE L ON THE MCP. I THOUGHT I SAW HIM REACH FOR THE ALT KNOB AND AT THAT TIME WENT HEAD DOWN TO REPROGRAM THE FMS TO INTERCEPT THE ARR UPON THE COMPLETION OF OUR TURN. AFTER ABOUT 90 DEGS OF HDG CHANGE, I LOOKED UP AND SAW THAT WE WERE LEVELING AT 8000 FT. I INFORMED THE CAPT THAT OUR ASSIGNED ALT WAS 9000 FT. I CALLED ATC TO VERIFY AND HE TOLD US TO JUST REMAIN AT 8000 FT NOW. REMAINDER OF FLT WAS UNEVENTFUL. COMPANY PROCS DICTATE THAT THE PF WILL MAKE ALL MCP CHANGES (INCLUDING ALT) WITH THE AUTOPLT ON. I SHOULD HAVE TECHNICALLY VIOLATED THIS POLICY AND SPUN IN 9000 FT. SINCE WE WERE IN A HIGH WORKLOAD, SHORT FUSE SCENARIO, I ALSO COULD HAVE BEEN MORE POSITIVE ABOUT VERIFYING THAT THE CAPT HAD HEARD THE ENTIRE CLRNC (LEVEL AT 9000 FT) AND NOT JUST THE PART ABOUT MAKING THE L 360 DEG TURN. BOTTOM LINE: SHOULD HAVE TO PUT THE RIGHT ALT IN THE WINDOW.

  9.  
  10. Accession Number: 399970
    Synopsis: L1011 ACFT ON SID AND LEVELING AT 5000 FT WITH AUTOTHRUST FMS ENGAGED, THE THROTTLES DIDN'T RETARD QUICKLY ENOUGH TO MAINTAIN REQUIRED 250 KTS. RPTR CAPT DISCONNECTED AND RETARDED THEM MANUALLY.
    Narrative: ON INITIAL CLB TO ASSIGNED SID ALT OF 5000 FT MSL, THE FMS AUTOTHRUST/THRUST MGMNT WERE ENGAGED AND APPEARED TO BE FUNCTIONING NORMALLY. REACHING INTERMEDIATE ALT OF 5000 FT MSL, THE ACFT WAS LEVELED OFF. AT THAT TIME THE THRUST LEVERS FAILED TO RETARD AS PRESCRIBED TO MAINTAIN 250 KTS. I DISENGAGED THE AUTOTHRUST AND IMMEDIATELY REDUCED PWR TO IDLE. DESPITE IMMEDIATE CORRECTIVE ACTION, THE ACFT ATTAINED A SPD OF 265 KIAS BEFORE CORRECTIVE ACTION TOOK EFFECT. THE FMS AND ASSOCIATED SYS WERE SET UP AND OPERATED IN ACCORDANCE WITH PUBLISHED PROCS. MY COPLT WAS A CHK AIRMAN AND CLAIMED THAT THE SYS WERE INCAPABLE OF MANAGING THE ACFT SPD IN THIS SCENARIO, EVEN THOUGH PUBLISHED GUIDANCE SAYS THAT IT WILL. THIS TYPE OF SPD OVERSHOOT SEEMS TO BE INEVITABLE WHEN USING OUR PUBLISHED PROCS. MOST CREWS DO NOT USE THE FMS FOR INITIAL CLB BECAUSE OF THIS PROB. I NEEDED TO USE IT IN ORDER TO DEMONSTRATE TO THE CHK AIRMAN MY ADHERENCE TO STANDARD PROCS.

  11.  
  12. Accession Number: 410212
    Synopsis: AN AIRLINE CAPT RPT REGARDING THE ACR'S DEACTIVATION OF THE GND PROX INHIBIT SWITCH ON THEIR B767'S. THIS SIT BECOMES AN EVENT WHENEVER THE CAPT'S AIR DATA COMPUTER MALFUNCTIONS. THEN, THE ONLY WAY TO STOP THE GPWS ALERT WHEN AN UNWANTED SIGNAL IS HEARD, IS TO PULL THE CIRCUIT BREAKERS. CAPT REQUESTS ACR TO INCLUDE THE INHIBITING OF THE GPWS FOR ANY AIR DATA COMPUTER FAILURES AND THE PARALLEL RESTORATION OF THAT SWITCH. HE CITES A DEFICIENCY IN THE B757 FLEET OF ANY INHIBITOR SWITCH.
    Narrative: REQUEST REVIEW OF MESSAGE NUMBER XXXX WHICH ANNOUNCES DEACTIVATION OF GND PROX INHIBIT SWITCH ON B767'S. FAILURE OF CAPT'S AIR DATA COMPUTER CAUSES BAD INPUTS TO GPWS EVEN AFTER BOOTSTRAPPING AIR DATA COMPUTER. ON B757'S AND ON B767'S WITH DEACTIVATED INHIBIT SWITCH FOR GPWS, NO METHOD EXISTS SHORT OF PULLING GPWS CIRCUIT BREAKERS TO QUIET INVALID GPWS WARNINGS ON APCH WITH FAILED CAPT'S AIR DATA COMPUTER, EVEN AFTER BOOTSTRAPPING, SO GPWS INPUT FROM L AIR DATA COMPUTER MUST BE UPSTREAM OF CAPT'S AIR DATA SELECTOR SWITCH SELECTING ALTERNATE. WHY NOT INSERT A PROC IN OPERATING MANUAL FOR FAILURE OF L AIR DATA COMPUTER WHICH INCLUDES INHIBITION OF GPWS, AND INSTEAD OF DEACTIVATING THE INHIBIT SWITCH ON B767'S, WHY NOT REACTIVATE THIS SWITCH ON B767'S AND INSTALL IT ON B757'S TO ENABLE PLTS TO QUIET INCORRECT GPWS WARNINGS AFTER FAILURE OF L AIR DATA COMPUTERS? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR DID NOT KNOW WHY THE COMPANY DISCONNECTED THE FUNCTION OF THE GPWS INHIBIT SWITCH. THE COMPANY HAS NOT YET REPLIED TO HIS DEBRIEF OF THE INCIDENT. ON TKOF THE CREW HAD LOST THE CAPT'S SIDE OF HIS PANEL DUE TO THE AIR DATA COMPUTER FAILURE, WITH THE AIRSPD INDICATOR, RATE OF CLB AND ALTIMETER INFO BEING LOST. THE CREW USED THE 'BOOTSTRAP SWITCH' TO OBTAIN INFO FROM THE FO'S SIDE FOR THE PIC'S USE. THE CREW THEN DISCUSSED WHAT WAS GOING TO BE AFFECTED ON THEIR APCH WHEN THEY RETURNED FOR AN APCH TO MIA. THEY WERE UNPLEASANTLY SURPRISED TO RECEIVE THE LOUD GPWS ALERT. THE CAPT SAID IT WAS IMPOSSIBLE TO PULL THE CIRCUIT BREAKERS WHILE ON APCH AT 1000 FT. THE B757 IS BELIEVED TO NOT HAVE THIS SWITCH AT ALL AND THE CAPT THOUGHT THAT HIS INCIDENT WAS A GRAPHIC CASE OF WHY THOSE ACFT SHOULD HAVE A GPWS INHIBIT SWITCH INSTALLED INSTEAD OF JUST HAVING ALL OF THE B767 INHIBIT SWITCHES BEING DISCONNECTED. THE ACFT DESIGN FEATURE OF THE GPWS ALERT SENSOR BEING UPSTREAM OF THE ALTERNATE SOURCE SWITCH DOES NOT THEN DIVERT OR AVOID THE ALERT SIGNAL WHEN USING THE ALTERNATE SOURCE SELECTOR.
Flight Deck Automation Issues Website  
© 1997-2013 Research Integrations, Inc.