A MD11 captain reported that on final descent the stabilizer out of trim fault annunciated. A short ...

Attributes
ACN	884766
Time
Date	201004
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Component
Aircraft Component	Horizontal Stabilizer Trim
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Flight Engineer Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 25000 Flight Crew Type 800
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Loss Of Aircraft Control

Narrative:

On approach while intercepting ILS runway xx localizer and descending from about 3;000 ft MSL to the cleared altitude to maintain 2;000 ft MSL (until passing FAF) we had about 10+ KTS on the FMS speed and slowing; gear down and flaps 15 with app/land armed with a stabilizer out of trim level 2 alert showed on ead (engine and alert dispaly). Asked first officer to check QRH and a short time later the autopilot disconnected and aircraft pitched down abruptly. Airspeed accelerated quickly. I rolled wings level and pulled back on yoke as I applied continuous up trim. Did not hear 'stabilizer motion' call out I expected; but did get a 'sink rate' call out. Managed to get nose above horizon and increased power flying back up to glide slope and getting on localizer. This all occurred while IMC; flew rest of approach manually to a normal landing. Discussed my experience and lengthy write-up with maintenance and waited while they did check of all fault codes during which they could not find anything wrong. Aircraft returned to base for further analysis.

Original NASA ASRS Text

Title: A MD11 Captain reported that on final descent the STAB OUT OF TRIM fault annunciated. A short time later the autopilot disconnected and the aircraft pitched down. The Captain regained control and landed safely. Maintenance could not immediately find the cause.

Narrative: On approach while intercepting ILS Runway XX LOC and descending from about 3;000 FT MSL to the cleared altitude to maintain 2;000 FT MSL (until passing FAF) we had about 10+ KTS on the FMS speed and slowing; gear down and flaps 15 with APP/LAND armed with a STAB OUT OF TRIM level 2 alert showed on EAD (Engine and Alert Dispaly). Asked First Officer to check QRH and a short time later the autopilot disconnected and aircraft pitched down abruptly. Airspeed accelerated quickly. I rolled wings level and pulled back on yoke as I applied continuous up trim. Did not hear 'stabilizer motion' call out I expected; but did get a 'sink rate' call out. Managed to get nose above horizon and increased power flying back up to glide slope and getting on LOC. This all occurred while IMC; flew rest of approach manually to a normal landing. Discussed my experience and lengthy write-up with maintenance and waited while they did check of all fault codes during which they could not find anything wrong. Aircraft returned to base for further analysis.

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.

A MD11 captain reported that on final descent the stabilizer out of trim fault annunciated. A short time later the autopilot disconnected and the aircraft pitched down. The captain regained control and landed safely. Maintenance could not immediately find the cause.