Narrative:

I was pilot flying and we were level at FL340; which was our filed altitude for our flight. We were cleared to FL330. The first officer repeated the clearance; set FL330; we both confirmed it; and I reached up and pressed vs and turned the wheel to initiate a descent at 1200 FPM. I then reached down to the throttles and brought the power back just a bit. In cruise we were doing about 300 KIAS; which was showing about .78M. The nose began to drop slightly for the descent; then suddenly the nose pitched over very aggressively. I reached up to the yoke and disconnected the autopilot and brought the nose up to a more acceptable attitude and looked over at ED1 [engine display] to see if there were any bad engine indications; and that's when I noticed on the bottom of ED1; the flaps had come out to 5 degrees. Just as quickly as I noticed they were down; they slowly started going back towards 0. We leveled off at FL330; and I turned the autopilot back on; and asked the first officer if had he accidentally touched the flap lever and hit it with a leg or anything; to which he replied no. We never heard any aural warnings; never got any master warnings/cautions; there were no other indications that anything had happened; except for seeing the white flap bar come out and stop at 5 degrees and then go back to zero; and once they were back to 0 the gear and flap indications stayed on for 60 seconds and went away. The aircraft was always in positive control; at no point was the aircraft out of my control and the rest of the descent and approach and arrival was normal. We did send maintenance and dispatch both ACARS messages informing them of what happened. We didn't declare an emergency or let ATC know. Everything happened so quickly and returned to normal. We went through all the aircraft synoptic pages and nothing was not normal; we didn't have any warning or caution messages; there was no aural overspeed or anything. Just the flaps came down for a few seconds and then went back up. I did open the QRH to the flap fail checklist; I didn't know if when we brought the flaps to 8 or any position really that we'd get a flap fail; I was trying to be proactive. The rest of the descent and approach was normal; and once at the gate I contacted maintenance for the write up; talked to dispatch to let them know; and then powered down the aircraft for the night. But once at the hotel; I started thinking more about what happened. We had an uncommanded flight control issue. The aircraft was never out of control; but we still had a flight control issue momentarily. At the time other than notifying maintenance and dispatch; I didn't think to let ATC know because nothing was wrong after the flaps came back up.

Related reports:

Google
 

Original NASA ASRS Text

Title: CRJ200 Flight Crew experiences uncommanded flap extension at FL340 followed by retraction; without the flap handle having ever moved. Flaps extended normally during approach at destination airport.

Narrative: I was pilot flying and we were level at FL340; which was our filed altitude for our flight. We were cleared to FL330. The First Officer repeated the clearance; set FL330; we both confirmed it; and I reached up and pressed VS and turned the wheel to initiate a descent at 1200 FPM. I then reached down to the throttles and brought the power back just a bit. In cruise we were doing about 300 KIAS; which was showing about .78M. The nose began to drop slightly for the descent; then suddenly the nose pitched over very aggressively. I reached up to the yoke and disconnected the autopilot and brought the nose up to a more acceptable attitude and looked over at ED1 [Engine Display] to see if there were any bad engine indications; and that's when I noticed on the bottom of ED1; the flaps had come out to 5 degrees. Just as quickly as I noticed they were down; they slowly started going back towards 0. We leveled off at FL330; and I turned the autopilot back on; and asked the First Officer if had he accidentally touched the flap lever and hit it with a leg or anything; to which he replied no. We never heard any aural warnings; never got any master warnings/cautions; there were no other indications that anything had happened; except for seeing the white flap bar come out and stop at 5 degrees and then go back to zero; and once they were back to 0 the gear and flap indications stayed on for 60 seconds and went away. The aircraft was always in positive control; at no point was the aircraft out of my control and the rest of the descent and approach and arrival was normal. We did send Maintenance and Dispatch both ACARS messages informing them of what happened. We didn't declare an emergency or let ATC know. Everything happened so quickly and returned to normal. We went through all the aircraft synoptic pages and nothing was not normal; we didn't have any warning or caution messages; there was no aural overspeed or anything. Just the flaps came down for a few seconds and then went back up. I did open the QRH to the flap fail checklist; I didn't know if when we brought the flaps to 8 or any position really that we'd get a flap fail; I was trying to be proactive. The rest of the descent and approach was normal; and once at the gate I contacted Maintenance for the write up; talked to Dispatch to let them know; and then powered down the aircraft for the night. But once at the hotel; I started thinking more about what happened. We had an uncommanded flight control issue. The aircraft was never out of control; but we still had a flight control issue momentarily. At the time other than notifying Maintenance and Dispatch; I didn't think to let ATC know because nothing was wrong after the flaps came back up.

Data retrieved from NASA's ASRS site as of April 2012 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.