Narrative:

In cruise (FL290); flaps started deploying and retracting sporadically uncommanded. Flaps extended up to 8 degrees. Associated 'flaps degraded' status message appeared and checkerboard on both speed tapes. The aircraft (still on autoplt) was pitching to compensate for the flap extension. At that point; emergency was declared and lower altitude requested and diverted to ZZZ. Captain performed zero flap landing in ZZZ. First apparent indication noticed was 'checkerboards' on the entire speed tape as we were traveling at .70 mach (approximately 270 KIAS). Eventually; we could feel the aircraft pitching to compensate for the flap deployment and retraction confirming that the flaps were actually moving. Flap indictor showed deployment up to 8 degrees. We requested a lower altitude and slower speed to accommodate altitude and speed limitations to prevent further damage to the flaps. We had to declare an emergency to get the altitude desired in a timely manner. We also requested direct ZZZ to get the aircraft steering towards a 'nearest suitable airport' in an effort to get the airplane on the ground before flight controllability became an issue. Since there was no guidance per the QRH for the given scenario; captain elected to perform a 'flaps fail message' QRH procedure to set the aircraft up for a zero flap landing. The aircraft did display a 'flaps degraded' status message which also provided no guidance. I assume that there was a malfunction in the flap lever or the computer that controls the flaps. Callback conversation with reporter revealed the following information: reporter has not been advised specifically of maintenance findings. He did fly the same aircraft about 10 days later and reviewed the maintenance log at that time. The fix for his event was the replacement of an egpws component. Subsequent to that maintenance action a similar event was written up. As he recalls the fix in that case was the replacement of either flap proximity sensors or a component of the flap/spoiler control units. At that time there were no further events and the aircraft operated normally for his flts.

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Original NASA ASRS Text

Title: CL60 EXPERIENCES UNCOMMANDED DEPLOYMENT AND RETRACTION OF FLAPS AT CRUISE.

Narrative: IN CRUISE (FL290); FLAPS STARTED DEPLOYING AND RETRACTING SPORADICALLY UNCOMMANDED. FLAPS EXTENDED UP TO 8 DEGS. ASSOCIATED 'FLAPS DEGRADED' STATUS MESSAGE APPEARED AND CHECKERBOARD ON BOTH SPD TAPES. THE ACFT (STILL ON AUTOPLT) WAS PITCHING TO COMPENSATE FOR THE FLAP EXTENSION. AT THAT POINT; EMER WAS DECLARED AND LOWER ALT REQUESTED AND DIVERTED TO ZZZ. CAPT PERFORMED ZERO FLAP LNDG IN ZZZ. FIRST APPARENT INDICATION NOTICED WAS 'CHECKERBOARDS' ON THE ENTIRE SPD TAPE AS WE WERE TRAVELING AT .70 MACH (APPROX 270 KIAS). EVENTUALLY; WE COULD FEEL THE ACFT PITCHING TO COMPENSATE FOR THE FLAP DEPLOYMENT AND RETRACTION CONFIRMING THAT THE FLAPS WERE ACTUALLY MOVING. FLAP INDICTOR SHOWED DEPLOYMENT UP TO 8 DEGS. WE REQUESTED A LOWER ALT AND SLOWER SPD TO ACCOMMODATE ALT AND SPD LIMITATIONS TO PREVENT FURTHER DAMAGE TO THE FLAPS. WE HAD TO DECLARE AN EMER TO GET THE ALT DESIRED IN A TIMELY MANNER. WE ALSO REQUESTED DIRECT ZZZ TO GET THE ACFT STEERING TOWARDS A 'NEAREST SUITABLE ARPT' IN AN EFFORT TO GET THE AIRPLANE ON THE GND BEFORE FLT CONTROLLABILITY BECAME AN ISSUE. SINCE THERE WAS NO GUIDANCE PER THE QRH FOR THE GIVEN SCENARIO; CAPT ELECTED TO PERFORM A 'FLAPS FAIL MESSAGE' QRH PROC TO SET THE ACFT UP FOR A ZERO FLAP LNDG. THE ACFT DID DISPLAY A 'FLAPS DEGRADED' STATUS MESSAGE WHICH ALSO PROVIDED NO GUIDANCE. I ASSUME THAT THERE WAS A MALFUNCTION IN THE FLAP LEVER OR THE COMPUTER THAT CTLS THE FLAPS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER HAS NOT BEEN ADVISED SPECIFICALLY OF MAINT FINDINGS. HE DID FLY THE SAME ACFT ABOUT 10 DAYS LATER AND REVIEWED THE MAINT LOG AT THAT TIME. THE FIX FOR HIS EVENT WAS THE REPLACEMENT OF AN EGPWS COMPONENT. SUBSEQUENT TO THAT MAINT ACTION A SIMILAR EVENT WAS WRITTEN UP. AS HE RECALLS THE FIX IN THAT CASE WAS THE REPLACEMENT OF EITHER FLAP PROXIMITY SENSORS OR A COMPONENT OF THE FLAP/SPOILER CONTROL UNITS. AT THAT TIME THERE WERE NO FURTHER EVENTS AND THE ACFT OPERATED NORMALLY FOR HIS FLTS.

Data retrieved from NASA's ASRS site as of May 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.