An airbus 300 on final approach at 1000 ft experienced uncommanded rudder inputs and rudder pedals v...

Attributes
ACN	436935
Time
Date	199905
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mia.airport
State Reference	FL
Altitude	agl single value : 1000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : mia.tower
Operator	common carrier : air carrier
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	descent : approach landing : go around
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	436935
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
ASRS Report	437035
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : published procedure other anomaly other anomaly
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : provided flight assist flight crew : declared emergency flight crew : executed go around
Consequence	faa : investigated other other
Factors
Maintenance	contributing factor : engineering procedure contributing factor : schedule pressure contributing factor : work cards performance deficiency : inspection performance deficiency : testing performance deficiency : scheduled maintenance performance deficiency : installation
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

Approaching runway 09R at mia. Captain landing and autoplt off. Flaps 20 degrees as gear extended felt uncommanded rudder inputs. Asked first officer if his feet were on pedals and they were not. Extended flaps to 40 degrees (landing configuration) and uncommanded rudder inputs became worse. Trying to figure out problem: no lights on overhead, hydraulic pressure and quantity normal, switched yaw dampers off and no better (a bit worse so dampers back on). Approaching runway was slightly high so decided to go around and try to resolve problem away from ground on downwind. During go around, called for flaps 20 degrees and gear up. Airspeed approximately 180 KTS. Aircraft started yawing violently left and right, mostly left. Rudder pedals were very stiff and without an enormous pressure impossible to move. Declared emergency, asked for landing any runway, was able to turn around for runway 27L. Put gear down prior to turn and flaps 40 degrees. Yaw got worse again so flaps 20 degrees and more speed. Near full aileron at this point, right, to maintain control. Rudder pedals very stiff, lnded and could not move pedals at all on ground but tiller worked steering so taxied to gate. Callback conversation with reporter revealed the following information: the reporter stated the aircraft rudder pedals were locked at neutral with the rudder swinging 18 degrees left and right from neutral. The reporter said the yaw dampers were disconnected and control was worse so the yaw dampers were reconnected. The reporter stated a go around was made and an emergency was declared. The reporter said the rudder pedals took enormous pressure to move but wer able to turn for a landing. The reporter said on the ground the rudder remained locked but nose steering was available. The reporter said the loss of control was traced to a defective autoplt yaw actuator clutch which did not disengage when switched off. Callback conversation with reporter of acn 437035 revealed the following information: the reporter stated the airplane was almost uncontrollable in yaw. The reporter said the initial maintenance report was a failed autoplt yaw actuator clutch which separates the autoplt from the yaw actuator. The reporter stated the unit was removed and sent back to the manufacturer in france for investigation.

Original NASA ASRS Text

Title: AN AIRBUS 300 ON FINAL APCH AT 1000 FT EXPERIENCED UNCOMMANDED RUDDER INPUTS AND RUDDER PEDALS VERY STIFF CAUSED BY A FAILED AUTOPLT RUDDER ACTUATOR.

Narrative: APCHING RWY 09R AT MIA. CAPT LNDG AND AUTOPLT OFF. FLAPS 20 DEGS AS GEAR EXTENDED FELT UNCOMMANDED RUDDER INPUTS. ASKED FO IF HIS FEET WERE ON PEDALS AND THEY WERE NOT. EXTENDED FLAPS TO 40 DEGS (LNDG CONFIGURATION) AND UNCOMMANDED RUDDER INPUTS BECAME WORSE. TRYING TO FIGURE OUT PROB: NO LIGHTS ON OVERHEAD, HYD PRESSURE AND QUANTITY NORMAL, SWITCHED YAW DAMPERS OFF AND NO BETTER (A BIT WORSE SO DAMPERS BACK ON). APCHING RWY WAS SLIGHTLY HIGH SO DECIDED TO GO AROUND AND TRY TO RESOLVE PROB AWAY FROM GROUND ON DOWNWIND. DURING GO AROUND, CALLED FOR FLAPS 20 DEGS AND GEAR UP. AIRSPEED APPROX 180 KTS. ACFT STARTED YAWING VIOLENTLY L AND R, MOSTLY L. RUDDER PEDALS WERE VERY STIFF AND WITHOUT AN ENORMOUS PRESSURE IMPOSSIBLE TO MOVE. DECLARED EMER, ASKED FOR LNDG ANY RWY, WAS ABLE TO TURN AROUND FOR RWY 27L. PUT GEAR DOWN PRIOR TO TURN AND FLAPS 40 DEGS. YAW GOT WORSE AGAIN SO FLAPS 20 DEGS AND MORE SPEED. NEAR FULL AILERON AT THIS POINT, R, TO MAINTAIN CTL. RUDDER PEDALS VERY STIFF, LNDED AND COULD NOT MOVE PEDALS AT ALL ON GROUND BUT TILLER WORKED STEERING SO TAXIED TO GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT RUDDER PEDALS WERE LOCKED AT NEUTRAL WITH THE RUDDER SWINGING 18 DEGS L AND R FROM NEUTRAL. THE RPTR SAID THE YAW DAMPERS WERE DISCONNECTED AND CTL WAS WORSE SO THE YAW DAMPERS WERE RECONNECTED. THE RPTR STATED A GO AROUND WAS MADE AND AN EMER WAS DECLARED. THE RPTR SAID THE RUDDER PEDALS TOOK ENORMOUS PRESSURE TO MOVE BUT WER ABLE TO TURN FOR A LNDG. THE RPTR SAID ON THE GROUND THE RUDDER REMAINED LOCKED BUT NOSE STEERING WAS AVAILABLE. THE RPTR SAID THE LOSS OF CTL WAS TRACED TO A DEFECTIVE AUTOPLT YAW ACTUATOR CLUTCH WHICH DID NOT DISENGAGE WHEN SWITCHED OFF. CALLBACK CONVERSATION WITH RPTR OF ACN 437035 REVEALED THE FOLLOWING INFO: THE RPTR STATED THE AIRPLANE WAS ALMOST UNCONTROLLABLE IN YAW. THE RPTR SAID THE INITIAL MAINT REPORT WAS A FAILED AUTOPLT YAW ACTUATOR CLUTCH WHICH SEPARATES THE AUTOPLT FROM THE YAW ACTUATOR. THE RPTR STATED THE UNIT WAS REMOVED AND SENT BACK TO THE MANUFACTURER IN FRANCE FOR INVESTIGATION.

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.

An airbus 300 on final approach at 1000 ft experienced uncommanded rudder inputs and rudder pedals very stiff caused by a failed autoplt rudder actuator.