Narrative:

On mar/wed/07 I was PF and PIC of a lear 25 going to mfe. During descent through approximately FL200; I extended the spoilers. Speeds and G forces were normal. About 6 seconds later there was a perceptible change in the flight characteristics as if something had 'let go.' the aircraft had a slight right rolling tendency equivalent to about full right roll trim deflection. I retracted the spoilers and the aircraft flew normally. I extended them again and got the same right rolling tendency. The first officer and I briefed that we would delay spoiler deployment on landing to ensure control throughout the rollout. A few mins later on about 2 mi final; the spoiler deployed light illuminated even though we had selected stow. The airplane again had a right rolling tendency; which I was easily able to overcome with aileron inputs. We landed normally without further incident. After landing inspection revealed the left spoiler was missing rivets and had cracked in the middle. The outboard half was bent aft at the crack. I completed the normal maintenance and dispatch notifications and notified my chief pilot of the malfunction by telephone.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN LJ-25 PILOT REPORTS THAT A SPOILER WAS DAMAGED BY THE AIRFLOW WHEN IT WAS DEPLOYED IN FLIGHT.

Narrative: ON MAR/WED/07 I WAS PF AND PIC OF A LEAR 25 GOING TO MFE. DURING DSCNT THROUGH APPROX FL200; I EXTENDED THE SPOILERS. SPDS AND G FORCES WERE NORMAL. ABOUT 6 SECONDS LATER THERE WAS A PERCEPTIBLE CHANGE IN THE FLT CHARACTERISTICS AS IF SOMETHING HAD 'LET GO.' THE ACFT HAD A SLIGHT R ROLLING TENDENCY EQUIVALENT TO ABOUT FULL R ROLL TRIM DEFLECTION. I RETRACTED THE SPOILERS AND THE ACFT FLEW NORMALLY. I EXTENDED THEM AGAIN AND GOT THE SAME R ROLLING TENDENCY. THE FO AND I BRIEFED THAT WE WOULD DELAY SPOILER DEPLOYMENT ON LNDG TO ENSURE CTL THROUGHOUT THE ROLLOUT. A FEW MINS LATER ON ABOUT 2 MI FINAL; THE SPOILER DEPLOYED LIGHT ILLUMINATED EVEN THOUGH WE HAD SELECTED STOW. THE AIRPLANE AGAIN HAD A R ROLLING TENDENCY; WHICH I WAS EASILY ABLE TO OVERCOME WITH AILERON INPUTS. WE LANDED NORMALLY WITHOUT FURTHER INCIDENT. AFTER LNDG INSPECTION REVEALED THE L SPOILER WAS MISSING RIVETS AND HAD CRACKED IN THE MIDDLE. THE OUTBOARD HALF WAS BENT AFT AT THE CRACK. I COMPLETED THE NORMAL MAINT AND DISPATCH NOTIFICATIONS AND NOTIFIED MY CHIEF PLT OF THE MALFUNCTION BY TELEPHONE.

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.