|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : zzz.airport|
|Altitude||agl single value : 0|
|Operator||common carrier : air carrier|
|Make Model Name||B757-200|
|Operating Under FAR Part||Part 121|
|Flight Phase||ground : taxi|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Experience||flight time last 90 days : 70|
flight time total : 18000
flight time type : 5000
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Experience||flight time last 90 days : 210|
flight time total : 15000
flight time type : 6000
|Anomaly||non adherence : company policies|
non adherence : published procedure
non adherence : far
|Independent Detector||other other : 4|
During preflight of B757; the first officer noticed ice and snow adhering to airframe; wings; and tail; which had pooled and refrozen in both engines aft of fan section. He notified me (captain); station; maintenance and deicing; and after looking at it myself; we agreed maintenance needed to view ice in engines (we sent an ACARS entering defect of ice in engines into electronic logbook). WX was cavok and forecast to remain so after severe winter storm previous day; so deicing only (with a 50/50 mix) was required (and took over an hour just off the gate; as station told us they were understaffed). Maintenance had us attempt to cycle reversers; which were frozen; requiring additional deicing. Deicing confirmed 'clean airplane; deicing complete;' and we continued normal pushback and start. Per fom guidance we elected to taxi out with flaps and slats retracted to prevent clutter on txwys from damaging/contaminating flaps and slats with gear spray. Upon arriving at departure end of runway; number 4 for takeoff; we set flaps 15; and completed before takeoff checklist. Purser then advised us a passenger sitting in window seat just aft of wing noticed ice accumulations on newly exposed flap sections. The first officer performed a visual inspection from cabin confirming this; and we returned to gate for additional deicing with flaps remaining extended to 15 degrees. Upon further discussion with maintenance; they noted that one of the overnight aircraft had been left with flaps extended. Airplane was again confirmed 'clean; deicing complete' by deicing operations. A normal push; start; taxi and takeoff followed. Observations: 1) after severe ice storm previous day; airplane should have been proactively inspected by maintenance; including inside engines and viewing fully extended flaps/slats; and then deiced early that morning well before our scheduled departure time. Storm was previous day; and weather next morning was cavok. There was no need or anticipation for anti-icing. This one; simple; proactive procedure would have mitigated the entire 4-HOUR delay and possible takeoff with ice adhering to flaps. Had the flight been at night; we never would have seen ice on flaps upon extension; especially since the wing illumination lights are aimed at the leading edges of the wings. 2) there is no guidance in aom/fom for inspection of flaps/slats after deicing and after flap/slat extension when taxiing in contaminated/clutter conditions with flaps retracted. In fact; the aom seems to mislead the crew into taxiing with flaps/slats retracted; then ensuring before takeoff checklist is complete after (and in this order) 'deicing is complete' and (then!) flaps are positioned for takeoff. There is no guidance for deicing/inspecting extended flaps unless additional precipitation has occurred. 3) strangely; what guidance there is on leaving flaps extended for inspection occurs on page referring to the end of the previous flight; upon taxi in. There is no mention of the possibility of deicing with flaps extended; as was necessary for our flight the next day after the weather event that possibly drove snow and freezing rain up into flap/slat gaps. While taxiing back; we informed dispatch via ACARS to alert next outbound B757 (which started from gate next to us) of this possible problem. They confirmed that their airplane was clean with flaps extended. Conclusion: while clarification and guidance should be added to aom/fom to alert other crews to this problem; I cannot emphasize enough that simple; proactive action on the part of station personnel (maintenance; deice coordination) could have prevented this incident (and 4 hour; costly delay); which could have resulted in a hull loss had it occurred at night. It is also notable that the station when queried stated that they were short-staffed to do this kind of proactive work; as well as short of staff to perform the deicing.
Original NASA ASRS Text
Title: A B757-200 FLT CREW RPTS ON TAXI OUT PAX NOTICED ICE ON TRAILING EDGE FLAPS UPON EXTENSION. THEY RETURNED TO THE GATE FOR ADDITIONAL DE-ICING.
Narrative: DURING PREFLIGHT OF B757; THE FO NOTICED ICE AND SNOW ADHERING TO AIRFRAME; WINGS; AND TAIL; WHICH HAD POOLED AND REFROZEN IN BOTH ENGINES AFT OF FAN SECTION. HE NOTIFIED ME (CAPT); STATION; MAINT AND DEICING; AND AFTER LOOKING AT IT MYSELF; WE AGREED MAINT NEEDED TO VIEW ICE IN ENGINES (WE SENT AN ACARS ENTERING DEFECT OF ICE IN ENGINES INTO ELECTRONIC LOGBOOK). WX WAS CAVOK AND FORECAST TO REMAIN SO AFTER SEVERE WINTER STORM PREVIOUS DAY; SO DEICING ONLY (WITH A 50/50 MIX) WAS REQUIRED (AND TOOK OVER AN HOUR JUST OFF THE GATE; AS STATION TOLD US THEY WERE UNDERSTAFFED). MAINT HAD US ATTEMPT TO CYCLE REVERSERS; WHICH WERE FROZEN; REQUIRING ADDITIONAL DEICING. DEICING CONFIRMED 'CLEAN AIRPLANE; DEICING COMPLETE;' AND WE CONTINUED NORMAL PUSHBACK AND START. PER FOM GUIDANCE WE ELECTED TO TAXI OUT WITH FLAPS AND SLATS RETRACTED TO PREVENT CLUTTER ON TXWYS FROM DAMAGING/CONTAMINATING FLAPS AND SLATS WITH GEAR SPRAY. UPON ARRIVING AT DEP END OF RWY; NUMBER 4 FOR TAKEOFF; WE SET FLAPS 15; AND COMPLETED BEFORE TAKEOFF CHECKLIST. PURSER THEN ADVISED US A PAX SITTING IN WINDOW SEAT JUST AFT OF WING NOTICED ICE ACCUMULATIONS ON NEWLY EXPOSED FLAP SECTIONS. THE FO PERFORMED A VISUAL INSPECTION FROM CABIN CONFIRMING THIS; AND WE RETURNED TO GATE FOR ADDITIONAL DEICING WITH FLAPS REMAINING EXTENDED TO 15 DEGS. UPON FURTHER DISCUSSION WITH MAINT; THEY NOTED THAT ONE OF THE OVERNIGHT ACFT HAD BEEN LEFT WITH FLAPS EXTENDED. AIRPLANE WAS AGAIN CONFIRMED 'CLEAN; DEICING COMPLETE' BY DEICING OPS. A NORMAL PUSH; START; TAXI AND TAKEOFF FOLLOWED. OBSERVATIONS: 1) AFTER SEVERE ICE STORM PREVIOUS DAY; AIRPLANE SHOULD HAVE BEEN PROACTIVELY INSPECTED BY MAINTENANCE; INCLUDING INSIDE ENGINES AND VIEWING FULLY EXTENDED FLAPS/SLATS; AND THEN DEICED EARLY THAT MORNING WELL BEFORE OUR SCHEDULED DEPARTURE TIME. STORM WAS PREVIOUS DAY; AND WEATHER NEXT MORNING WAS CAVOK. THERE WAS NO NEED OR ANTICIPATION FOR ANTI-ICING. THIS ONE; SIMPLE; PROACTIVE PROC WOULD HAVE MITIGATED THE ENTIRE 4-HOUR DELAY AND POSSIBLE TAKEOFF WITH ICE ADHERING TO FLAPS. HAD THE FLIGHT BEEN AT NIGHT; WE NEVER WOULD HAVE SEEN ICE ON FLAPS UPON EXTENSION; ESPECIALLY SINCE THE WING ILLUMINATION LIGHTS ARE AIMED AT THE LEADING EDGES OF THE WINGS. 2) THERE IS NO GUIDANCE IN AOM/FOM FOR INSPECTION OF FLAPS/SLATS AFTER DEICING AND AFTER FLAP/SLAT EXTENSION WHEN TAXIING IN CONTAMINATED/CLUTTER CONDITIONS WITH FLAPS RETRACTED. IN FACT; THE AOM SEEMS TO MISLEAD THE CREW INTO TAXIING WITH FLAPS/SLATS RETRACTED; THEN ENSURING BEFORE TAKEOFF CHECKLIST IS COMPLETE AFTER (AND IN THIS ORDER) 'DEICING IS COMPLETE' AND (THEN!) FLAPS ARE POSITIONED FOR TAKEOFF. THERE IS NO GUIDANCE FOR DEICING/INSPECTING EXTENDED FLAPS UNLESS ADDITIONAL PRECIP HAS OCCURRED. 3) STRANGELY; WHAT GUIDANCE THERE IS ON LEAVING FLAPS EXTENDED FOR INSPECTION OCCURS ON PAGE REFERRING TO THE END OF THE PREVIOUS FLIGHT; UPON TAXI IN. THERE IS NO MENTION OF THE POSSIBILITY OF DEICING WITH FLAPS EXTENDED; AS WAS NECESSARY FOR OUR FLT THE NEXT DAY AFTER THE WEATHER EVENT THAT POSSIBLY DROVE SNOW AND FREEZING RAIN UP INTO FLAP/SLAT GAPS. WHILE TAXIING BACK; WE INFORMED DISPATCH VIA ACARS TO ALERT NEXT OUTBOUND B757 (WHICH STARTED FROM GATE NEXT TO US) OF THIS POSSIBLE PROB. THEY CONFIRMED THAT THEIR AIRPLANE WAS CLEAN WITH FLAPS EXTENDED. CONCLUSION: WHILE CLARIFICATION AND GUIDANCE SHOULD BE ADDED TO AOM/FOM TO ALERT OTHER CREWS TO THIS PROB; I CANNOT EMPHASIZE ENOUGH THAT SIMPLE; PROACTIVE ACTION ON THE PART OF STATION PERSONNEL (MAINT; DEICE COORD) COULD HAVE PREVENTED THIS INCIDENT (AND 4 HOUR; COSTLY DELAY); WHICH COULD HAVE RESULTED IN A HULL LOSS HAD IT OCCURRED AT NIGHT. IT IS ALSO NOTABLE THAT THE STATION WHEN QUERIED STATED THAT THEY WERE SHORT-STAFFED TO DO THIS KIND OF PROACTIVE WORK; AS WELL AS SHORT OF STAFF TO PERFORM THE DEICING.
Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.