MD80 CAPT ADVISES ACFT ANGLE OF ATTACK SYS SUGGEST ACFT WT IN EXCESS OF LEGAL MAXIMUMS.

Date: 2006-01 · Aircraft: MD-83 · Phase: ground

Anomalies: deviation-discrepancy-procedural-far|deviation-discrepancy-procedural-published-material-policy

Synopsis

MD80 CAPT ADVISES ACFT ANGLE OF ATTACK SYS SUGGEST ACFT WT IN EXCESS OF LEGAL MAXIMUMS.

Narrative

AT BRAKE RELEASE; WE SAW OUR WT INDICATE 159900 LBS. TKOF WAS ON RWY 32R BY REQUEST WITH ATC AS RWY 32L IN MY EXPERIENCE WOULD BE TOO SHORT FOR THIS TYPICAL FLT TO MMSD. RWY USE WAS EXCESSIVE; SPD LOW WAS ON IN CLBOUT. ALPHA SPD WOULD NOT EXTINGUISH UNTIL 264 KTS FOR CLEAN 'MIN/MAN.' OUR PAPERWORK SPD WAS 260 KTS AT 160000 LBS. THE ANGLE OF ATTACK COMPUTERS WERE TELLING US THAT FOR A KT PER 2000 LBS; IN LEVEL FLT AT 5000 FT OVER MIDWAY HEADING S; WE WERE ABOUT 8000 LBS OVER THE MAX GROSS WT AND SINGLE CAPABILITY OF OUR ACFT AT TKOF! GENTLEMEN; ADVISORY CIRCULAR 120-27C AND FAA ORDER N8400.40 SHOW THAT THE AVERAGE WT OF THE AMERICAN PERSON TRAVELING A BLIND RANDOM TEST HAD INCREASED 30.16 LBS. THE FAA IN ITS NEW MATH WISDOM ALLOWS PART 121 OPERATORS TO USE 50% OF THEIR OWN EMPIRICAL DATA! IN OTHER WORDS; 10 LBS PER PERSON AND 5 LBS PER BAG INCREASE. THIS GIVES AN AVERAGE OF 195 LBS WINTER WT (PAX AND CARRY-ON) AND 30 LBS PER AVERAGE CHKED BAG WT THAT ACR X USES. IF YOU DO THE MATH; THAT GIVES A FULL MD80 WITH 139 PAX A BIAS OF 2107 LBS TO THE HVY SIDE (139 X 15.16 LBS). I HAVE SENT DIGITAL PHOTOS TO MR X TO SHOW MY OWN OFFLOAD AUDIT. I REGRET THAT MY NEW CAMERA'S FUNCTIONS DID NOT ALLOW ME TO GET USABLE OBVERSE PHOTOS OF 1 AFT LUGGAGE CART AS WELL AS THE MID CARGO CART. THE PHOTOS SHOW EQUAL LOADING ON L AND R SIDES OF THE CARTS TO ALLOW THE COUNTING OF BAGS. THE POINT I AM TRYING TO MAKE IS THAT THE SIZE OF CHKED LUGGAGE IS AS GREAT AS THE SIZE INCREASE OF THE AVERAGE PAX. ON THIS FLT; THE MID AND AFT CARGO COMPARTMENTS WERE CUBED OUT AND THE BAG COUNT WAS OFF 40-50. 30 LB LUGGAGE AVERAGE WT IS UNREALISTIC TO CRUISE AND VACATION DESTS. JUST LOOK AT THE PICTURES. PEOPLE DON'T GO TO THESE DESTS FOR DAY TRIPS. THEY GO FOR WK LONG VACATIONS AND PACK SO AS NOT TO DO LAUNDRY (ASK YOUR WIFE). ANGLE OF ATTACK ALPHA SPD IS AN ACCURATE TOOL AND SHOULD BE USED. SPD LOW; ACCORDING TO OUR BOOK IS THE FIRST INDICATOR OF AN APCH TO STALL. MY SUGGESTION TO GET A REAL TIME FEEL FOR THIS PROB IS TO HAVE PLTS AND CHK AIRMEN FOR THE NEXT 90 DAYS DO ACTUAL V2 +10 KT CLBOUTS TO CREATE A KNOWLEDGE BASE; IF V2 +10 KTS GIVES A 20% MARGIN ABOVE STALL TO 15 DEGS OF BANK THEN SPD LOW SHOULD NEVER ILLUMINATE BY DEFAULT. WITH ARPT; TERRAIN AND RNAV DEP CONSIDERATIONS SET THE SPD BUG FOR V2 +10 KTS WITH THE AUTOTHROTTLES 'ON' AT 1000 FT AFL INSTEAD OF THE 'HALF RATE;' LITANY PUSH 'VERT SPD' AND NOSE OVER TO GET THE THROTTLES OFF AT THROTTLE LIMIT AND RETRACT FLAPS. IF YOU SEE 'SPD LOW;' THEN ACCELERATE TO THE CLEAN 'MIN/MAN' BUG IN LEVEL FLT. WITH THE FLAPS AND SLATS RETRACTED SET THE ORANGE SPD BUG TO THE TOP WHITE BUG. IF ALPHA IS ON AT THE PAPERWORK COMPUTED BUG; THEN IN 1 KT INCREMENTS INCREASE THE ORANGE BUG UNTIL ALPHA GOES OUT. NOTE THAT SPD AND USE THE CARDS TO INTERPOLATE YOUR ACTUAL WT. THE REVERSE CAN BE ACCOMPLISHED FOR LNDG. INSTEAD OF PUTTING THE SLATS OUT PRIOR TO TOP WHITE BUG; SET THE ORANGE SPD BUG TO MATCH THE CLEAN 'MIN/MAN' BUG AND AS YOU SLOW FOR APCH DETERMINE WHERE ALPHA SPD IS. MOST FLTS ARE FAIRLY ACCURATE; THAT I HAVE SEEN. WITHIN A KT OR TWO. IT'S THE FLTS LIKE MINE TO MMSD THAT WILL BE AN EYE OPENER. SET YOUR SPD BUGS TO THE ANGLE OF ATTACK SPD AND COMPARE TO THE ACFT LNDG WT ON THE FUEL GAUGE. NOTE THE DIFFERENCE AND USE THE ANGLE OF ATTACK COMPUTED WT TO RE-SET THE NEW ACTUAL 'REF' SPDS. LUGGAGE CARTS CAN BE WEIGHED JUST LIKE THE GRAVEL PIT DOES WHEN I STOP FOR SUPPLIES. THE SCALES THEY USE ARE ELECTRONIC AND ACCURATE. THIS WOULD BE ONE METHOD TO TEST THE 'AVERAGE' FAA NUMBER ON SUSPECTED FLT; AND WOULD BE WORTH THE COST AND TROUBLE TO IMPLEMENT REGARDLESS OF THE INDUSTRY LOSSES; WHEN YOU CONSIDER THE COST BENEFIT ANALYSIS OF A HULL LOSS AND LAWSUITS; IF WE ARE CHARGING $25 FOR EXCESS BAG WT ABOVE 50 LBS; WE ARE ALREADY OVER THE AVERAGE WT OF 30 LBS AT THE TICKET COUNTER. WHY THEN ISN'T THE REAL WT MADE PUBLIC TO LOAD CTL ON A PIECE-BY-PIECE; FLT-BY-FLT BASIS. WE HAVE BAR CODES ON THE TAGS FOR THE OTHER INFO; WHY NOT INCLUDE THE ACTUAL LUGGAGE WT? THEN KNOWING WHICH COMPARTMENT IT GOES IN MAKES BAL A SCIENCE NOT A GUESS. IF A HVY WT BAG GOES THROUGH A HUB; DOES THE WT OF THE BAG AND ITS HEAVINESS FOLLOW IT TO THE CONNECTING FLT OR DOES IT ONLY COUNT ON THE FIRST LEG? IN MY OPINION; EVERY CHKED BAG SHOULD BE WEIGHED AT THE COUNTER. IF IT'S OVER 30 LBS; SO NOTE! IF WE GO TO THE TROUBLE OF REVENUE ENHANCEMENT BY CHARGING FOR HVY BAGS; LET'S GO TO THE TROUBLE OF SAFETY ENHANCEMENT AS WELL BY XMITTING THE BAG WT TO THE PLTS. AN AUDIT OF BAG COUNT PER SUSPECT OR RANDOM FLT AND ACTUAL WT ON A CART-BY-CART BASIS TO SET A NEW 'ACTUAL' WT WOULD BE A START TO ENHANCED SAFETY. THIS MIGHT EVEN SHED LIGHT ON STALLS AT HIGH ALT; COULD THEY BE CAUSED BY IMPROPER HVY WTS; IE; LOW LOAD CLOSEOUTS LEADING TO HIGHER THAN POSSIBLE CRUISE ALTS? THINK ABOUT IT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISED HE HAD TAKEN PHOTO DOCUMENTATION OF THE ANOMALOUS AIRSPD AND ANGLE OF ATTACK INDICATIONS/WARNINGS AND FORWARDED THEM TO HIS ACR FLT OPS DEPT. THEY RESPONDED VERY POSITIVELY AND ARE ACTIVELY PURSUING MEANS TO RESOLVE THE PROB; EVEN GOING SO FAR AS TO ACTUALLY WEIGH BAGS ON THE TYPE OF RTES IN QUESTION. RPTR WAS IMPRESSED THAT LESS THAN 1 WK AFTER HIS INITIAL RPTS; THE COMPANY HAD PROVIDED MMSD WITH LEGITIMATE STEEL SCALES FOR WEIGHING BAGGAGE VICE THE SMALL BATHROOM TYPE PREVIOUSLY USED. FINALLY; HE NOTED THAT PROVISIONS EXIST FOR IDENTING BAGS THAT 'APPEAR' TO EXCEED THE 30 LB STANDARD IN WHICH CASE THEY ARE MARKED WITH AN ORANGE 'HVY' TAG. THE RPTR INDICATED THE ACHILLES HEEL OF THIS PROC IS THAT THERE IS NO REQUIREMENT TO WEIGH BAGS AND DOING SO IS AT THE DISCRETION OF THE AGENT CHKING IN THE PAX.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.