Narrative:

I was the captain/PF on a night passenger flight to smf which was our first flight together as a crew. It was the first officer's second flight on this aircraft. Climbing; passing FL260 and FL269; the autoplt began to level the aircraft and the feel of some type of drag was noticed. I disconnected the autoplt and noticed the flaps were starting to come down. I pushed the flap lever to 0 and noted the aircraft parameters. The leading edge flaps light was amber but never turned green. The trailing edge flaps were between 0 and 1. After the incident; I realized that I had reached up to the right CDU about 5-15 seconds prior to the flaps coming down. It was my habit to move my r-hand around the right side of the throttles to make a CDU input when the throttles were forward. I could have mistakenly brushed the flap handle when I pulled my hand back from the CDU. The first officer stated that he usually checked the flaps in the 0 detent after raising the flaps. He could not specifically remember in this case. Upon landing; we realized that the flap handle would not easily go to the 0 position. It then had to be hit down into the detent. A logbook write-up was made. The mechanic agreed that the flap handle was difficult to move forward to the 0 position. We believe that the flap overspd was caused by 1) PNF not checking the flap handle in the 0 detent. 2) PF brushing the handle as he pulled his hand back from the right CDU. 3) possible mis-rigging of the flap handle preventing its seating in the 0 detent.

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Original NASA ASRS Text

Title: A B737-300 FLT CREW INADVERTENTLY EXTENDED THE WING FLAPS AT 27000 FT IN PART BECAUSE THE FLAP HANDLE WAS NOT ENGAGED IN THE DETENT.

Narrative: I WAS THE CAPT/PF ON A NIGHT PAX FLT TO SMF WHICH WAS OUR FIRST FLT TOGETHER AS A CREW. IT WAS THE FO'S SECOND FLT ON THIS ACFT. CLBING; PASSING FL260 AND FL269; THE AUTOPLT BEGAN TO LEVEL THE ACFT AND THE FEEL OF SOME TYPE OF DRAG WAS NOTICED. I DISCONNECTED THE AUTOPLT AND NOTICED THE FLAPS WERE STARTING TO COME DOWN. I PUSHED THE FLAP LEVER TO 0 AND NOTED THE ACFT PARAMETERS. THE LEADING EDGE FLAPS LIGHT WAS AMBER BUT NEVER TURNED GREEN. THE TRAILING EDGE FLAPS WERE BTWN 0 AND 1. AFTER THE INCIDENT; I REALIZED THAT I HAD REACHED UP TO THE R CDU ABOUT 5-15 SECONDS PRIOR TO THE FLAPS COMING DOWN. IT WAS MY HABIT TO MOVE MY R-HAND AROUND THE R SIDE OF THE THROTTLES TO MAKE A CDU INPUT WHEN THE THROTTLES WERE FORWARD. I COULD HAVE MISTAKENLY BRUSHED THE FLAP HANDLE WHEN I PULLED MY HAND BACK FROM THE CDU. THE FO STATED THAT HE USUALLY CHKED THE FLAPS IN THE 0 DETENT AFTER RAISING THE FLAPS. HE COULD NOT SPECIFICALLY REMEMBER IN THIS CASE. UPON LNDG; WE REALIZED THAT THE FLAP HANDLE WOULD NOT EASILY GO TO THE 0 POS. IT THEN HAD TO BE HIT DOWN INTO THE DETENT. A LOGBOOK WRITE-UP WAS MADE. THE MECH AGREED THAT THE FLAP HANDLE WAS DIFFICULT TO MOVE FORWARD TO THE 0 POS. WE BELIEVE THAT THE FLAP OVERSPD WAS CAUSED BY 1) PNF NOT CHKING THE FLAP HANDLE IN THE 0 DETENT. 2) PF BRUSHING THE HANDLE AS HE PULLED HIS HAND BACK FROM THE R CDU. 3) POSSIBLE MIS-RIGGING OF THE FLAP HANDLE PREVENTING ITS SEATING IN THE 0 DETENT.

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.