Narrative:

At approximately 100 ft AGL on final approach aircraft yawed abruptly to left with left wing dropping. Aircraft was realigned with runway and a rather abrupt landing was made. During exit from runway to taxiway going through approximately 30 degrees of right turn nose wheel steering was lost. Aircraft had experienced a hydraulic failure. Aircraft was towed to gate without further incident. Maintenance found that #1 ground spoiler hydraulic actuator had come apart (separated) from air frame and was no longer attached to aircraft. Actuator hydraulic cylinder had separated from flange where it attaches to air frame or flight control surface. Callback conversation with reporter revealed the following information: callback conversation revealed that the surface wind condition was calm wind with temperature in low 60's and not a condition to cause the wing to drop. The aircraft was on target speed in a normal approach attitude when the wing went down and the aircraft yawed left. The reporter said he used rudder to align the aircraft and bring the wing up and the landing though 'abrupt' was not hard enough to write up as a hard landing or to cause the type of hydraulic actuator failure that was discovered. There was an FAA inspector on board at the time but he was not an aci. He did discuss the problem with the flight crew but this was before the broken actuator was discovered during post-flight inspection. The reporter does not think he would have been able to make a successful go around because of the flap position and possible control problems. A company report was filed but there has been no response at this time. The hydraulic actuator came apart much like the cap comes off a ball point pen. One end separated causing the failure and loss of hydraulic fluid from the primary system.

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Original NASA ASRS Text

Title: ACR MLG HAD CTL PROBLEM ON SHORT FINAL. AFTER LNDG DISCOVERED PRIMARY SYS HYD FAILURE CAUSED BY FAILURE OF SPOILER ACTUATOR.

Narrative: AT APPROX 100 FT AGL ON FINAL APCH ACFT YAWED ABRUPTLY TO L WITH L WING DROPPING. ACFT WAS REALIGNED WITH RWY AND A RATHER ABRUPT LNDG WAS MADE. DURING EXIT FROM RWY TO TAXIWAY GOING THROUGH APPROX 30 DEGS OF R TURN NOSE WHEEL STEERING WAS LOST. ACFT HAD EXPERIENCED A HYD FAILURE. ACFT WAS TOWED TO GATE WITHOUT FURTHER INCIDENT. MAINT FOUND THAT #1 GND SPOILER HYD ACTUATOR HAD COME APART (SEPARATED) FROM AIR FRAME AND WAS NO LONGER ATTACHED TO ACFT. ACTUATOR HYD CYLINDER HAD SEPARATED FROM FLANGE WHERE IT ATTACHES TO AIR FRAME OR FLT CTL SURFACE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CALLBACK CONVERSATION REVEALED THAT THE SURFACE WIND CONDITION WAS CALM WIND WITH TEMP IN LOW 60'S AND NOT A CONDITION TO CAUSE THE WING TO DROP. THE ACFT WAS ON TARGET SPD IN A NORMAL APCH ATTITUDE WHEN THE WING WENT DOWN AND THE ACFT YAWED L. THE RPTR SAID HE USED RUDDER TO ALIGN THE ACFT AND BRING THE WING UP AND THE LNDG THOUGH 'ABRUPT' WAS NOT HARD ENOUGH TO WRITE UP AS A HARD LNDG OR TO CAUSE THE TYPE OF HYD ACTUATOR FAILURE THAT WAS DISCOVERED. THERE WAS AN FAA INSPECTOR ON BOARD AT THE TIME BUT HE WAS NOT AN ACI. HE DID DISCUSS THE PROBLEM WITH THE FLC BUT THIS WAS BEFORE THE BROKEN ACTUATOR WAS DISCOVERED DURING POST-FLT INSPECTION. THE RPTR DOES NOT THINK HE WOULD HAVE BEEN ABLE TO MAKE A SUCCESSFUL GAR BECAUSE OF THE FLAP POS AND POSSIBLE CTL PROBLEMS. A COMPANY RPT WAS FILED BUT THERE HAS BEEN NO RESPONSE AT THIS TIME. THE HYD ACTUATOR CAME APART MUCH LIKE THE CAP COMES OFF A BALL POINT PEN. ONE END SEPARATED CAUSING THE FAILURE AND LOSS OF HYD FLUID FROM THE PRIMARY SYS.

Data retrieved from NASA's ASRS site as of July 2007 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.