Individually Owned: 150,657
Corporate Owned: 137,281
Seattle-Tacoma Int'l Airport
Aircraft Accident/Incident Report
Seattle, Washington 98188
Tuesady, January 21, 1997 6:20 PST
NTSB Narrative Summary Released at Completion of Accident
While on final approach, the airplane commenced a rapid, uncommanded roll to the right when the 35-degree flap setting was selected. The flying pilot (1st officer) was able to counter the roll by applying almost full opposite aileron, during which time, he felt the aileron jam momentarily and then break free. The airplane landed without further incident. An examination revealed that the inboard, aft end of the right wing outboard flap was detached from the wing flap track. This resulted in flap asymmetry and mechanical interference with the aileron. The flap track roller bearing was seized and the flap mounting bracket was torn and separated from the bearing. The bearing outer roller was loose and could be shifted axially on the bearing outer ring. This allowed the outer roller flange to wear against and eventually tear through the flap mounting bracket. The operator was not using the most recent (revised) Beech 1900D maintenance manuals at the time of the incident and the airplane had not been subjected to a detailed inspection of the flap roller brackets, roller bearings, and attachment hardware as outlined in revised sections of the manual.
NTSB Probable Cause Narrative
an axial shift of the aft flap track bearing's outer roller, resulting in erosion and failure of the flap track bracket/bearing assembly. A factor relating to the incident was: inadequate inspection of the flap roller bearing/bracket assemblies.
Event Information
| Type of Event | Incident |
| Event Date | 1/21/1997 |
| Event Day of the Week | Tuesday |
| Time of Event | 620 |
| Event Time Zone | Pacific Standard Time |
| Event City | SEATTLE |
| Event State | WASHINGTON |
| Event Country | -- |
| Zipcode of the event site | 98188 |
| Event Date Year | 1997 |
| Event Date Month | 1 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | SEATTLE-TACOMA INT'L |
| Event Location Nearest Airport ID | SEA |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 2 |
| Degrees magnetic from airport | 240 |
| Airport Elevation | 429 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 559 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | 160 |
| Weather Observation Facility ID | SEA |
| Elevation of weather observation facility | 429 |
| Distance of event from weather observation facility (units?) | 2 |
| Time Zone of the weather observation | PST |
| Lighting Conditions | Night/Dark |
| Lowest Ceiling Height | 4000 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 7 |
| Dew Point at event time (in degress fahrenheit) | 3 |
| Wind Direction (degrees magnetic) | 170 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| 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 | 7 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5000 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jan 21 1997 12:00AM |
| NTSB Notification Time | 900 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 12:06PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N75ZV |
| NTSB Number | SEA97IA051 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 135: Air Taxi & Commuter |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Beech |
| Aircraft Model | 1900D |
| Aircraft Series Identifier | 1900D |
| Aircraft Serial Number | UE-75 |
| Certified Max Gross Weight | 16950 |
| 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 | 21 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Jan 16 1997 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 7027 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | MESA AIRLINES, INC. |
| Aircraft Owner Street Address | 2325 E. 30TH STREET |
| Aircraft Owner City | FARMINGTON |
| Aircraft Owner State | NM |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 87401 |
| Operator is an individual? | -- |
| Operator Name | MESA AIRLINES |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | |
| Operator City | |
| Operator State | |
| Operator Country | |
| Operator Zip code | |
| Operator Code | |
| Owner has at least one certificate | Yes - certificate holder |
| 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 | Scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | ALW |
| Departure City | WALLA WALLA |
| Departure State | WA |
| Departure Country | |
| Departure Time | 500 |
| Departure Time Zone | PST |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | SEA |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 16L |
| Runway Length | 11410 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |