An MD80 captain reported that his aircraft dove for the runway at fifty feet during a VMC autoland c...

Narrative:

Flight plan requested an autoland check. Attempted an autoland at our destination on a CAT III runway. Approach normal; approximately 75 ft AGL left wing dips then returns level followed by rapid nose tuck. Elevation was approximately fifty feet. Disconnected autopilot/auto throttles with aggressive recovery inputs necessary to keep aircraft from landing on its nose with high rate of descent. The touchdown itself was within all normal parameters. Minimal time to recognize and recover from high threat situation. Subsequent maintenance action replaced both dfcg's and several servos. The autoland check should be considered an emergency procedure. This day was VMC. Sterile areas were clear.

Original NASA ASRS Text

Title: An MD80 Captain reported that his aircraft dove for the runway at fifty feet during a VMC autoland check on a CAT III runway. Aircraft control was regained before touchdown. The Flight Guidance Computers and several flight control servos were replaced by maintenance.

Narrative: Flight plan requested an autoland check. Attempted an autoland at our destination on a CAT III runway. Approach normal; approximately 75 FT AGL left wing dips then returns level followed by rapid nose tuck. Elevation was approximately fifty feet. Disconnected autopilot/auto throttles with aggressive recovery inputs necessary to keep aircraft from landing on its nose with high rate of descent. The touchdown itself was within all normal parameters. Minimal time to recognize and recover from high threat situation. Subsequent maintenance action replaced both DFCG's and several servos. The autoland check should be considered an Emergency Procedure. This day was VMC. Sterile areas were clear.

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.

Attributes
ACN	904231
Time
Date	201008
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	MD-83
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Loss Of Aircraft Control

An MD80 captain reported that his aircraft dove for the runway at fifty feet during a VMC autoland check on a CAT III runway. Aircraft control was regained before touchdown. The flight guidance computers and several flight control servos were replaced by maintenance.