MD-11
Flight Crew Last 90 Days 67; Flight Crew Total 5000; Flight Crew Type 1600
Human-Machine Interface; Troubleshooting
Aircraft Equipment Problem Critical; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control; Flight Crew FLC Overrode Automation
Aircraft
We were in level flight at 3;000 MSL when cleared for a visual approach to 17R. When the Captain selected approach/land mode the aircraft started an uncommanded high pitch/high power right turn. The Captain re-selected 3;000 FT; but we continued the high power/high pitch turn. The Captain disconnected the autopilot and started a descent with the autothrottles still commanding high power. The First Officer selected 2;800 FT in control panel multiple times but the autothrottles did not respond. The Captain then disconnected the autothrottles. Landing was uneventful; but the aircraft had climbed to nearly 4;000 FT before we regained control.
An MD-11 flight crew was surprised when the aircraft entered a climbing right turn and the autothrottles advanced commensurately when the approach/land mode autoflight mode was selected. They disconnected the autopilot and autothrottles but gained nearly 1;000 FT before regaining flight path control.