Narrative:

Cruising at FL340 on autopilot; suddenly aircraft rolled up to 60 degrees of bank and began a descent in excess of 2;000 ft per minute before we could recover control. Altitude deviated down to FL330 with a subsequent recovery to FL340. [We] immediately advised center of an autopilot hard over with the altitude deviation. Upon recovery; center asked if we could maintain rvsm and we responded yes; but after further consideration decided that we should not continue in rvsm and requested a descent out of rvsm airspace. We were cleared to FL280 and continued to our filed destination without further incident. I wrote up the autopilot as inoperative; canceled the remainder of the flights; spoke to our maintenance; and deferred the autopilot to fly manually to home station at FL250; flying off autopilot. I am unaware of any traffic conflict at this time and was not advised by ATC that there had been a traffic conflict. The jet is now in maintenance (troubleshooting the problem).

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Original NASA ASRS Text

Title: A Falcon 20 autopilot amplifier malfunctioned at FL340 which resulted in a rapid roll to 60 degrees; and a 1;000 FT altitude loss. The flight descended out of RVSM airspace for the remainder of the flight.

Narrative: Cruising at FL340 on autopilot; suddenly aircraft rolled up to 60 degrees of bank and began a descent in excess of 2;000 FT per minute before we could recover control. Altitude deviated down to FL330 with a subsequent recovery to FL340. [We] immediately advised Center of an autopilot hard over with the altitude deviation. Upon recovery; Center asked if we could maintain RVSM and we responded yes; but after further consideration decided that we should not continue in RVSM and requested a descent out of RVSM airspace. We were cleared to FL280 and continued to our filed destination without further incident. I wrote up the autopilot as INOP; canceled the remainder of the flights; spoke to our Maintenance; and deferred the autopilot to fly manually to home station at FL250; flying off autopilot. I am unaware of any traffic conflict at this time and was not advised by ATC that there had been a traffic conflict. The jet is now in maintenance (troubleshooting the problem).

Data retrieved from NASA's ASRS site 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.