B737-300 crew had uncommanded rudder input on approach and touchdown on runway 26R at atl.

Attributes
ACN	498445
Time
Date	200101
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : atl.airport
State Reference	GA
Altitude	msl single value : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : atl.tower
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 26r other
Flight Phase	descent : approach landing other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : instrument pilot : multi engine pilot : commercial pilot : atp
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 900
ASRS Report	498445
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

During visual approach upon selecting 30 degrees then 40 degrees flaps, a pronounced right and left yaw was noticed. Aircraft dispatched from hsv to ATC with yaw damper inoperative. MEL restr for airspeed complied with wind 310/10 KTS. Yaw oscillations did not create any feedback to rudder pedals, was controled with aileron only. 30 degrees flaps landing was reselected (40 degrees flap initially). Nose yawed +/- 5 to 10 degrees from center line line-up. The oscillation continued through landing and upon touchdown. A noticeable shudder felt when nose wheel touched down. Landing was aligned with runway (no crab). The shudder felt as if the nosewheel was not aligned. Callback conversation with reporter revealed the following information: the crew was flying a B737-300 aircraft. The aircraft yaw damper was inoperative and on the MEL inoperative, and deactivated. The captain indicated that air carrier mntnc had 5 pages of corrective items replaced. He thinks that every conceivable item that could be replaced, was. He flew the aircraft several days later and everything was normal.

Original NASA ASRS Text

Title: B737-300 CREW HAD UNCOMMANDED RUDDER INPUT ON APCH AND TOUCHDOWN ON RWY 26R AT ATL.

Narrative: DURING VISUAL APCH UPON SELECTING 30 DEGS THEN 40 DEGS FLAPS, A PRONOUNCED R AND L YAW WAS NOTICED. ACFT DISPATCHED FROM HSV TO ATC WITH YAW DAMPER INOP. MEL RESTR FOR AIRSPEED COMPLIED WITH WIND 310/10 KTS. YAW OSCILLATIONS DID NOT CREATE ANY FEEDBACK TO RUDDER PEDALS, WAS CTLED WITH AILERON ONLY. 30 DEGS FLAPS LNDG WAS RESELECTED (40 DEGS FLAP INITIALLY). NOSE YAWED +/- 5 TO 10 DEGS FROM CENTER LINE LINE-UP. THE OSCILLATION CONTINUED THROUGH LNDG AND UPON TOUCHDOWN. A NOTICEABLE SHUDDER FELT WHEN NOSE WHEEL TOUCHED DOWN. LNDG WAS ALIGNED WITH RWY (NO CRAB). THE SHUDDER FELT AS IF THE NOSEWHEEL WAS NOT ALIGNED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE CREW WAS FLYING A B737-300 ACFT. THE ACFT YAW DAMPER WAS INOP AND ON THE MEL INOP, AND DEACTIVATED. THE CAPT INDICATED THAT ACR MNTNC HAD 5 PAGES OF CORRECTIVE ITEMS REPLACED. HE THINKS THAT EVERY CONCEIVABLE ITEM THAT COULD BE REPLACED, WAS. HE FLEW THE ACFT SEVERAL DAYS LATER AND EVERYTHING WAS NORMAL.

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.