B737 FLT OBSERVED LEADING EDGE DEVICES EXTEND WHILE CLBING TO ALT.

Narrative

CLBING THROUGH FL310 IN IMC CONDITIONS WITH THE AUTOPLT ON; THE ACFT UNEXPECTEDLY BEGAN TO VIBRATE. I IMMEDIATELY NOTICED THE RED SPD TAPE ON THE AIRSPD INDICATOR INDICATING A FLAP OVERSPD. AS PF; I IMMEDIATELY TOOK CTL OF THE ACFT AND DISENGAGED THE AUTOPLT. 1 SECOND LATER; THE AMBER LEADING EDGE DEVICE IN-TRANSIT INDICATOR ILLUMINATED. THE CAPT IMMEDIATELY RESTOWED THE HANDLE TO THE 0 (ZERO) POS. MAINT WAS NOTIFIED INFLT AND WITH ALL SYS AND ACFT HANDLING QUALITIES NORMAL; IN ADDITION TO A CABIN RPT FROM THE PURSER THAT EVERYTHING WAS NORMAL; WE CONTINUED TO TPA. ON ARR; ALL FLT CTLS OPERATED NORMALLY. MAINT MET US ON ARR AND INSPECTED THE ACFT. THIS WAS OUR LAST FLT OF THE DAY. WHILE WORKING THE RADAR YESTERDAY DURING THE CLB PHASE; I MAY HAVE 'TOUCHED' THE FLAP LEVER AS I MOVED MY HAND FROM THE RADAR CTL UNIT. HOWEVER; DURING TAXI-IN; I TRIED TO DUPLICATE THIS POTENTIAL THEORY AND NEARLY BROKE MY WATCHBAND AND THE HANDLE DID NOT MOVE AT ALL FROM THE DOWN POS. THIS MORNING; WE WERE ASSIGNED TO THE SAME ACFT FOR FLT ON A TPA-IAD SEGMENT. NOW PERFORMING PNF DUTIES; I OPERATED THE FLAPS ON DEP AND THEY FELT FINE. HOWEVER; ON TAXI-IN; ABOUT 90 SECONDS AFTER THE FLAPS WERE RETRACTED TO THE UP POS; THE CAPT SAID; 'LOOK AT THE HANDLE NOW!' THEY HAD POPPED UP TO A POS BTWN ZERO AND ONE. THIS WAS THE EVENT THAT MAY EXPLAIN WHAT HAPPENED ON THE PREVIOUS FLT. IF THE FLAP HANDLE HAD THE SAME MALFUNCTION YESTERDAY THAT THE CAPT AND I JUST WITNESSED; THE FLAPS WOULD HAVE INITIATED A SEQUENCE TO THE 1 POS WITH JUST THE SLIGHTEST BRUSH OF THE HANDLE. THE FLAPS WILL MOVE TO 1 AT A POINT BTWN UP AND 1; NOT ONLY IN 1 OR EVEN CLOSE TO 1. THE CAPT DIRECTED ME TO NOTIFY MAINT TO MEET US AT THE GATE. I DEBRIEFED MAINT AND THE ACFT WAS REMOVED FROM SVC. ALTHOUGH IT MAY APPEAR THAT THE CAUSE WAS AN IRREGULARITY PERHAPS IN THE INTERIM; WE COULD CHANGE THE AFTER TKOF CHKLIST TO READ 'FLAPS-UP/DETENT'...JUST LIKE THE BEFORE TKOF CHKLIST.