Narrative:

During cruise repositioning from heavy maintenance; the first officer serving as the flying pilot; we experienced a rudder hard over while cruising at FL380. While attempting to regain control of the aircraft after the rudder upset and the autopilot was turned off we inadvertently climbed 500 ft. When positive control of the aircraft was regained we returned to our assigned altitude of FL380. During the time of the altitude excursion the rudder hard over did not return to normal initially. The rudder input was overridden manually while troubleshooting. Turning the yaw damper off did not release the rudder input. The rudder hydraulic power was turned off at this time and the rudder returned to a neutral position. This returned positive control of the aircraft. Center was contacted and advised of the altitude deviation as well as the flight control malfunction. At this time we advised them that we would be non rvsm compliant and requested clearance to remain at our current altitude or request a descent below rvsm airspace. They subsequently issued a clearance to FL270. Dispatch and maintenance control were contacted and advised of the situation. It was determined that we would continue to our scheduled destination. The flight continued without further incident. This aircraft has just returned from heavy maintenance. It has had a history of uncommanded yaw inputs and has a 'chronic' problem with this prior to induction into maintenance. No problem was observed during induction or during the acceptance test flights. This problem needs to be tracked and the cause determined and corrected.

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Original NASA ASRS Text

Title: A DC8 on a ferry flight following heavy maintenance had a rudder hard over which was controlled only after rudder hydraulic power was removed. This aircraft had a history of this anomaly which was not addressed in maintenance.

Narrative: During cruise repositioning from heavy maintenance; the First Officer serving as the flying pilot; we experienced a rudder hard over while cruising at FL380. While attempting to regain control of the aircraft after the rudder upset and the autopilot was turned off we inadvertently climbed 500 FT. When positive control of the aircraft was regained we returned to our assigned altitude of FL380. During the time of the altitude excursion the rudder hard over did not return to normal initially. The rudder input was overridden manually while troubleshooting. Turning the yaw damper off did not release the rudder input. The rudder hydraulic power was turned OFF at this time and the rudder returned to a neutral position. This returned positive control of the aircraft. Center was contacted and advised of the altitude deviation as well as the flight control malfunction. At this time we advised them that we would be NON RVSM compliant and requested clearance to remain at our current altitude or request a descent below RVSM airspace. They subsequently issued a clearance to FL270. Dispatch and Maintenance Control were contacted and advised of the situation. It was determined that we would continue to our scheduled destination. The flight continued without further incident. This aircraft has just returned from heavy maintenance. It has had a history of uncommanded YAW inputs and has a 'CHRONIC' problem with this prior to induction into maintenance. No problem was observed during induction or during the acceptance test flights. This problem needs to be tracked and the cause determined and corrected.

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.