Narrative:

Malfunction of leading edge flaps/slats on B737-800 during climb out from dca en route to ewr, air carrier flight xyz. Flaps/slats remained in full extend position when selected to 'up' with the flap handle. Could not continue to ewr based on fuel endurance consideration at required slow speed and lower altitude. Made landing at nearest suitable airport, which was washington dulles. Declared emergency due to the flight control malfunction. Planned for an abnormal landing at iad, but flaps extended normally to 30 degrees and we landed with no control problems or difficulty. No asymmetric problem in-flight. All slats and flaps on leading edge remained in full extend position after landing at iad. I think it was an electronic lockout problem with this new B737-800 model that made us unable to retract slats either in-flight or on the ground. Recall checked clear before takeoff at dca. Callback conversation with reporter revealed the following information: the reporter stated the leading edge position indicating system operated normally prior to takeoff and in climb out, but on full extension the overhead panel extend amber transit light came on. The reporter said at this time the proximity sensor electronics unit warning light came on which is a no go item. The reporter stated when maintenance arrived to check the aircraft the reporter was advised that 30 proximity sensors are involved in the leading edge position sensing circuit and any one can cause a lockup. The reporter said there were no previous reports on leading edge position problems in the logbook and is not aware of any on the new B737-800 fleet.

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Original NASA ASRS Text

Title: A B737-800 ON CLBOUT AT 9000 FT DECLARED AN EMER AND DIVERTED DUE TO UNABLE TO RETRACT THE LEADING EDGE DEVICES WITH THE FLAP HANDLE UP.

Narrative: MALFUNCTION OF LEADING EDGE FLAPS/SLATS ON B737-800 DURING CLBOUT FROM DCA ENRTE TO EWR, ACR FLT XYZ. FLAPS/SLATS REMAINED IN FULL EXTEND POS WHEN SELECTED TO 'UP' WITH THE FLAP HANDLE. COULD NOT CONTINUE TO EWR BASED ON FUEL ENDURANCE CONSIDERATION AT REQUIRED SLOW SPD AND LOWER ALT. MADE LNDG AT NEAREST SUITABLE ARPT, WHICH WAS WASHINGTON DULLES. DECLARED EMER DUE TO THE FLT CTL MALFUNCTION. PLANNED FOR AN ABNORMAL LNDG AT IAD, BUT FLAPS EXTENDED NORMALLY TO 30 DEGS AND WE LANDED WITH NO CTL PROBS OR DIFFICULTY. NO ASYMMETRIC PROB INFLT. ALL SLATS AND FLAPS ON LEADING EDGE REMAINED IN FULL EXTEND POS AFTER LNDG AT IAD. I THINK IT WAS AN ELECTRONIC LOCKOUT PROB WITH THIS NEW B737-800 MODEL THAT MADE US UNABLE TO RETRACT SLATS EITHER INFLT OR ON THE GND. RECALL CHKED CLR BEFORE TKOF AT DCA. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE LEADING EDGE POS INDICATING SYS OPERATED NORMALLY PRIOR TO TKOF AND IN CLBOUT, BUT ON FULL EXTENSION THE OVERHEAD PANEL EXTEND AMBER TRANSIT LIGHT CAME ON. THE RPTR SAID AT THIS TIME THE PROX SENSOR ELECTRONICS UNIT WARNING LIGHT CAME ON WHICH IS A NO GO ITEM. THE RPTR STATED WHEN MAINT ARRIVED TO CHK THE ACFT THE RPTR WAS ADVISED THAT 30 PROX SENSORS ARE INVOLVED IN THE LEADING EDGE POS SENSING CIRCUIT AND ANY ONE CAN CAUSE A LOCKUP. THE RPTR SAID THERE WERE NO PREVIOUS RPTS ON LEADING EDGE POS PROBS IN THE LOGBOOK AND IS NOT AWARE OF ANY ON THE NEW B737-800 FLEET.

Data retrieved from NASA's ASRS site as of July 2007 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.