ON TKOF AFTER DE-ICING; A B737-700 LOST ALL FLT INSTRUMENTS REQUIRING A PITOT STATIC INPUT. AN EMER WAS DECLARED AND FLT DIVERTED TO A VMC ARPT.
Synopsis
ON TKOF AFTER DE-ICING; A B737-700 LOST ALL FLT INSTRUMENTS REQUIRING A PITOT STATIC INPUT. AN EMER WAS DECLARED AND FLT DIVERTED TO A VMC ARPT.
Narrative
ON TKOF FROM ZZZ AT APPROX 400 FT WE LOST ALL AIRSPD/ALT AND VVI READOUTS INCLUDING STANDBY INSTRUMENTS. WE ALSO HAD A WINDSHEAR WARNING. WE USED EMER THRUST AND 12-15 DEGS PITCH ATTITUDE TO ENSURE CLBOUT. PNF CALLED ALTS OFF OF RADAR ALTIMETER. AIRSPD WAS FLUCTUATING BETWEEN 60-180 KTS AND THE STALL WARNING STICK SHAKER KEPT ACTIVATING WHEN THE AIRSPD GAUGE DROPPED BELOW 100 KTS. BOTH ALTIMETERS WERE STUCK AT 200 FT MSL AND THE VVI WAS FLUCTUATING UP AND DOWN. PNF ADVISED PF TO CONTINUE 12-15 DEGS PITCH WITH EMER POWER TO ENSURE CLB EVEN WITH WHAT APPEARED TO BE ERRONEOUS STALL WARNINGS. TWR WAS TOLD OF THE EMER AND SWITCHED US TO APCH CTL FOR CLB AND VECTORS. RMI'S APPEARED TO BE WORKING SO WE WERE VECTORED SW INITIALLY FOR ZZZ1. WE INFORMED APCH CTL THAT WE DID NOT WANT TO DSND THROUGH THE CLOUDS WITHOUT PITOT STATIC INSTRUMENTS. ZZZ1 WAS RPTING 7000 FT BROKEN SO WE REQUESTED AN AIRFIELD THAT WAS CAVU. ZZZ2 WAS RPTED TO BE CAVU. WE ASKED FOR A VECTOR TO ZZZ2. WE ALSO HAD A LEADING EDGE SLAT TRANSIT LIGHT AND OUR LEADING EDGES WERE STUCK DOWN WITH THE TRAILING EDGE FLAPS UP. WE REQUESTED AT LEAST A 10000 FT RWY DUE TO FLAPS 15 APCH. WE ARRIVED OVER ZZZ2 AT WHAT APPEARED TO BE 10000 FT OF ALT. WE HAD ZZZ3 VISUAL BY THEN AND ASKED FOR A STRAIGHT IN ILS TO RWY 27L. WE THEN RAN THE CHKLIST FOR LEADING EDGE FLAP TRANSIT LIGHT AND CHKED OPC DATA TO ENSURE WE COULD LAND FLAPS 15. WE THEN PROCEEDED TO AN UNEVENTFUL LNDG AT ZZZ3. AFTER ROLLOUT; WE TAXIED OFF THE RWY AND TOLD GND CTL THAT WE WERE SECURE AND WOULD NOT REQUIRE EMER SVCS ANY LONGER. WE TAXIED TO THE GATE AND SHUT DOWN THE ACFT. DUE TO RWY LENGTH AT ZZZ; WE HAD USED A BLEEDS OFF TKOF WITH THE APU POWERING THE LEFT AIR CONDITIONING PACK. WE FORGOT TO RECONFIGURE DURING THE CLBOUT AND WE GOT A CABIN ALT WARNING HORN AT 10000 FT CABIN ALT. WE THEN RECONFIGURED THE PACKS AND BLEEDS AND RESET THE CABIN ALT WARNING SWITCH. THE PITOT STATIC EMER TOOK ALL OUR ATTENTION AND WE MISSED THE CABIN ALT AND LEADING EDGE SLAT PROBLEM INITIALLY. I AM NOT SURE WHAT CAUSED THIS EVENT BUT IT WAS VERY COLD WITH BLOWING SNOW. WE HAD TO DEICE WITH HEATED TYPE I FLUID THEN TYPE IV FLUID WAS APPLIED FOR ANTI-ICE PROTECTION. THE WHOLE AIRPLANE WAS COVERED WITH BOTH FLUIDS INCLUDING BOTH WINDSCREENS. WE WERE AIRBORNE WITHIN 10-12 MINUTES OF INITIAL ANTI-ICE APPLICATION. THE PUBLISHED HOLDOVER TIME WAS 30-50 MINUTES. A PIREP FROM AN ACFT ON APCH CALLED FOR GUSTY WINDS AND MODERATE ICING BELOW 1000 FT. DURING THE EMER WE USED PITCH/POWER AMD RADAR ALTIMETER READINGS TO ENSURE ADEQUATE CLB WAS MAINTAINED. GND SPD WAS ALSO AVAILABLE BUT NEITHER OF US THOUGHT TO USE IT TIL WE HAD ATTAINED VFR ON TOP. DURING THE DSCNT FOR LNDG; WE STARTED TO GET WHAT APPEARED TO BE AIRSPD AND ALT READOUTS BUT WE WERE NOT SURE OF THE ACCURACY SO WE USED RADAR ALTIMETER ALTS AND GND SPD VERSUS TWR WIND READOUTS FOR OUR AIRSPD ONCE WE WERE ON THE GLIDESLOPE. WE WALKED AWAY FROM THIS INCIDENT BECAUSE WE WERE ABLE TO SEPARATE OURSELVES FROM OUR TRAINING ON STALLS AND TRUST THAT 12-15 DEGS OF PITCH ATTITUDE WITH EMER THRUST WOULD SUSTAIN OUR CLBOUT EVEN THOUGH WE HAD INTERMITTENT STICK SHAKER AND AT ONE TIME A DON'T SINK WARNING DUE TO ERRONEOUS VVI READOUTS. HAD WE CHASED THE STICK SHAKER; WE COULD HAVE DSNDED WITH DISASTROUS CONSEQUENCES.CALLBACK CONVERSATION WITH RPTR ACN 684037 REVEALED THE FOLLOWING INFO: RPTR SAID THAT AN EXTENSIVE INVESTIGATION BY HIS ACR HAS NOT YET PRODUCED A DEFINITIVE CAUSE OF THE PITOT STATIC SYSTEM'S BEHAVIOR; ADDING MAINT DISCOVERED A SMALL AMOUNT OF LIQUID IN THE STATIC TUBES BUT IT IS UNKNOWN IF THAT CAUSED A BLOCKAGE. THE RPTR INDICATED THE GND CREW SPRAYED TYPE I AND TYPE IV FLUID ON THE FRONT PART OF THE ACFT DURING PRE-DEP DE-ICING. IT IS POSSIBLE THAT FLUID ENTERED THE PITOT STATIC SYSTEM. THE RPTR INDICATED THE ACCEPTED PROC IS TO DE-ICE/ANTI-ICE ONLY FROM THE FORWARD PART OF THE WINGS AFT. THIS CREW SAID THE FORWARD PART OF THE ACFT; INCLUDING THE COCKPIT; WAS SPRAYED. REPORTEDLY; AT THE END OF THE FLT; WHEN THE ACFT DSNDED OUT OF 5400 FT; THE CAPT'S INSTRUMENTS RETURNED WHILE THE FO'S INSTRUMENTS RETURNED AT 4000 FT; BUT NEITHER WERE COMPLETELY STABLE AND THEREFORE WERE NOT RELIED UPON AS PRIMARY FLT INSTRUMENTS.SUPPLEMENTAL INFO FROM RPTR ACN 684030: DURING TKOF; LOST ALL ALT; IAS; VVI; AND STBY IAS; ALT; BOTH CAPT AND FO SIDES. ONLY HAD FMC GND SPD INDICATOR AND ATTITUDE FLT INFO. ALSO HAD WINDSHEAR WARNING AND BOTH L AND R LE SLATS FULLY EXTEND. USED POWER SETTINGS AND ACFT PITCH TO CLB TO VMC CONDITION. ABOUT 5 TO 8 MINUTES IN THE WX UNTIL BREAKING OUT ABOUT 8000 TO 9000 FT. THE HUD INFO WAS ALSO BAD. DECLARED AN EMER WITH APCH CTL. STAYED APPROX 10000 TO 11000 FT AND USED FMC GND SPEED TO DIVERT TO ZZZ3 WHICH WAS VMC. FLEW A FLAPS 15 APCH TO RWY 27L. WX DURING TKOF WAS WINDS 330/25 G40; BLOWING SNOW; -7 DEGS CELSIUS AND 29.42; VIS 3/4.CALLBACK CONVERSATION WITH RPTR ACN 684030 REVEALED THE FOLLOWING INFO: THE RPTR STATED RIGHT AFTER LIFTOFF LOST BOTH CAPT'S AND FO'S IAS; ALT; VVI; AND STBY ALT AND IAS. DECLARED AN EMER BUT COULD NOT RETURN TO THE DEP ARPT DUE TO WX. ALSO HAD WINDSHEAR WARNING AND LEADING EDGE DEVICES DEPLOYED. DID HAVE FMC GND SPD AND ATTITUDE INDICATIONS. USED POWER SETTINGS AND ACFT PITCH TO CLB OUT TO VMC CONDITIONS. THIS AIRPLANE WAS DEICED PRIOR TO DEP WITH TYPE IV DEICING FLUID AND THE FORWARDED PART OF THE FUSELAGE WAS COVERED WITH THE 'GREEN GOO' DRIPPING AND RUNNING OFF THE SIDES. THE RPTR NOTED THAT THE STATIC PORTS ON THE B737-700 ARE NOT LOCATED IN THE PITOT PROBE BUT ON THE SIDES OF THE FORWARD FUSELAGE JUST FORWARD OF THE #1 L AND #1 R ENTRANCE DOOR AND ARE NOT HEATED. THESE PORTS WERE COVERED WITH THE DEICING FLUID AND MAY HAVE PLUGGED THE SMALL HOLES. THE ACFT WAS DEICED BY COMPANY GND PERSONNEL.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.