A falcon 20 autopilot amplifier malfunctioned at FL340 which resulted in a rapid roll to 60 degrees;...

Attributes
ACN	1161777
Time
Date	201404
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Falcon 20FJF/20C/20D/20E/20F
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Autoflight System
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Flight Engineer Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 21000 Flight Crew Type 800
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Altitude Excursion From Assigned Altitude Inflight Event / Encounter Loss Of Aircraft Control

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).

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.

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.