Individually Owned: 150,657
Corporate Owned: 137,281
Anchorage Int'l Airport
Aircraft Accident/Incident Report
Anchorage, Alaska 99502
Wednesday, March 11, 1998 11:45 AST
NTSB Narrative Summary Released at Completion of Accident
During parking at the gate, the airplane's rudder began a rapid rudder oscillation which shook the entire airplane. Postincident testing determined that the rudder was oscillating approximately 1.5 degrees either side of centerline, solely within the authority of the yaw damper. No corresponding cockpit rudder pedal movement occurred. Further testing revealed a loss of grease to the yaw rate gyro spin bearings, and corresponding damage to the spin and gimbal bearings. The yaw damp coupler and gyro had accumulated 24,850 hours in service.
NTSB Probable Cause Narrative
The dynamic imbalance in the yaw rate gyro, which provided input to the yaw damper and rudder. A factor was the deteriorated grease in the gyro bearings.
Event Information
| Type of Event | Incident |
| Event Date | 3/11/1998 |
| Event Day of the Week | Wednesday |
| Time of Event | 1145 |
| Event Time Zone | Atlantic Standard Time |
| Event City | ANCHORAGE |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99502 |
| Event Date Year | 1998 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | ANCHORAGE INT'L AIRPORT |
| Event Location Nearest Airport ID | ANC |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | 144 |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Unknown |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Unknown |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 0 |
| Air Temperature at event time (in degrees celsius) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 81 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5001 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Mar 11 1998 12:00AM |
| NTSB Notification Time | 1500 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Feb 23 2001 1:54PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Unknown |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N733AR |
| NTSB Number | ANC98IA026 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Boeing |
| Aircraft Model | 737-205 |
| Aircraft Series Identifier | 737-205 |
| Aircraft Serial Number | 1256 |
| Certified Max Gross Weight | 124500 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 119 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Mar 10 1998 12:00AM |
| Airframe hours since last inspection | 3 |
| Airframe Hours | 24850 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | FIRST SECURITY BANK UT TRUSTEE |
| Aircraft Owner Street Address | 79 SOUTH MAIN STREET |
| Aircraft Owner City | SALT LAKE CITY |
| Aircraft Owner State | UT |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 84111 |
| Operator is an individual? | -- |
| Operator Name | ARCO ALASKA, INC. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 6601 SOUTH AIRPARK PLACE |
| Operator City | ANCHORAGE |
| Operator State | AK |
| Operator Country | |
| Operator Zip code | 99502 |
| Operator Code | SROM |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Business |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | PUO |
| Departure City | PRUDHOE BAY |
| Departure State | AK |
| Departure Country | |
| Departure Time | 0 |
| Departure Time Zone | |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | ANC |
| Destination City | |
| Destination State | AK |
| Destination Country | |
| Specific Phase of Flight | Standing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 23 2001 1:54PM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |