As a B737 captain was entering ACARS data at FL320 he inadvertently moved the flap handle which caus...

Narrative:

We felt a buffet and found airspeed well into the barber pole. First officer flying; I retarded the thrust levers to reduce speed. Our initial evaluation was we'd entered a mountain wave (165 KTS of wind at altitude); but the indicated speeds didn't make any sense. We started checking for other causes; pitot heat; etc. And found the flaps selected and indicating one (speed approximately 270 KIAS and at FL320). I retracted the flaps at approximately 235 KIAS; hand flew the airplane to check for roll or vibration and found all indications normal. We continued to our destination and landed without further event. We also limited descent speed as a precaution. What I believe happened: I was beginning to type a wind report to dispatch when the autopilot trimmed the airplane. The trim wheel bumped my arm and I must have made contact with the flap handle enough to knock it out of the detent (reaching around the thrust levers and flaps to reach the keyboard). Approximately two or three minutes later the event occurred. If I bumped the flaps it was the result of being bumped by the trim wheel; and I had no idea anything had transpired. Just plain stupid bad luck; but it seems to me something that could be repeated and everyone should be aware of the possibility. Sure didn't know I touched the flap handle and they didn't come out immediately.

Original NASA ASRS Text

Title: As a B737 Captain was entering ACARS data at FL320 he inadvertently moved the flap handle which caused airframe vibrations and a flap overspeed. When they recognized the error power was reduced and the flaps raised.

Narrative: We felt a buffet and found airspeed well into the barber pole. First Officer flying; I retarded the thrust levers to reduce speed. Our initial evaluation was we'd entered a mountain wave (165 KTS of wind at altitude); but the indicated speeds didn't make any sense. We started checking for other causes; pitot heat; etc. and found the flaps selected and indicating one (speed approximately 270 KIAS and at FL320). I retracted the flaps at approximately 235 KIAS; hand flew the airplane to check for roll or vibration and found all indications normal. We continued to our destination and landed without further event. We also limited descent speed as a precaution. What I believe happened: I was beginning to type a wind report to Dispatch when the autopilot trimmed the airplane. The trim wheel bumped my arm and I must have made contact with the flap handle enough to knock it out of the detent (reaching around the thrust levers and flaps to reach the keyboard). Approximately two or three minutes later the event occurred. If I bumped the flaps it was the result of being bumped by the trim wheel; and I had no idea anything had transpired. Just plain stupid bad luck; but it seems to me something that could be repeated and everyone should be aware of the possibility. Sure didn't know I touched the flap handle and they didn't come out immediately.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	997801
Time
Date	201203
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	B737-400
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	ACARS
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Other / Unknown Deviation - Speed All Types

As a B737 captain was entering ACARS data at FL320 he inadvertently moved the flap handle which caused airframe vibrations and a flap overspeed. When they recognized the error power was reduced and the flaps raised.