A B737-300 on landing experienced severe vibrations until stopped. Found the right main landing gear...

Attributes
ACN	685306
Time
Date	200601
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	landing : roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 200 flight time total : 2000 flight time type : 600
ASRS Report	685306
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 8000
ASRS Report	685028
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

On a smooth landing to runway 7R in ZZZ; the jet started to shake with weight on wheels. The vibrations became more violent as the aircraft slowed. We taxied clear of runway 7R to hold between the runways on taxiway F. After coming to a complete stop; we started the APU and shut down both engines. Maintenance came out and inspected the aircraft along with airport personnel. They inspected the right main landing gear and said the wheel was cocked about 20-30 degrees off and the shimmy damper had come off (which they found on the runway). We deplaned the passenger via airstairs and took a bus back to the terminal. The captain did an excellent job of keeping the passenger and crew informed of the problem and the solution. Callback conversation with reporter revealed the following information: the reporter stated the cause of the right main landing gear shimmy damper departing the aircraft and the right wheel cocked 20-30 degrees off center is unknown. Maintenance has reportedly not released any details on the maintenance action taken.

Original NASA ASRS Text

Title: A B737-300 ON LNDG EXPERIENCED SEVERE VIBRATIONS UNTIL STOPPED. FOUND THE R MAIN LNDG GEAR SHIMMY DAMPER HAD DEPARTED THE ACFT AND THE R WHEEL WAS COCKED 20-30 DEGS OFF CTR.

Narrative: ON A SMOOTH LNDG TO RWY 7R IN ZZZ; THE JET STARTED TO SHAKE WITH WT ON WHEELS. THE VIBRATIONS BECAME MORE VIOLENT AS THE ACFT SLOWED. WE TAXIED CLR OF RWY 7R TO HOLD BTWN THE RWYS ON TXWY F. AFTER COMING TO A COMPLETE STOP; WE STARTED THE APU AND SHUT DOWN BOTH ENGS. MAINT CAME OUT AND INSPECTED THE ACFT ALONG WITH ARPT PERSONNEL. THEY INSPECTED THE R MAIN LNDG GEAR AND SAID THE WHEEL WAS COCKED ABOUT 20-30 DEGS OFF AND THE SHIMMY DAMPER HAD COME OFF (WHICH THEY FOUND ON THE RWY). WE DEPLANED THE PAX VIA AIRSTAIRS AND TOOK A BUS BACK TO THE TERMINAL. THE CAPT DID AN EXCELLENT JOB OF KEEPING THE PAX AND CREW INFORMED OF THE PROB AND THE SOLUTION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE R MAIN LNDG GEAR SHIMMY DAMPER DEPARTING THE ACFT AND THE R WHEEL COCKED 20-30 DEGS OFF CTR IS UNKNOWN. MAINT HAS REPORTEDLY NOT RELEASED ANY DETAILS ON THE MAINT ACTION TAKEN.

Data retrieved from NASA's ASRS site as of January 2009 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 B737-300 on landing experienced severe vibrations until stopped. Found the right main landing gear shimmy damper had departed the aircraft and the right wheel was cocked 20-30 degrees off center.