Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Monterey, California 93940
Sunday, February 25, 2001 21:55 PST
NTSB Narrative Summary Released at Completion of Accident
The lone cabin attendant in the aft end of the airplane sustained a broken ankle when she was thrown to the floor after the airplane experienced an abrupt pitch change during descent. The captain had the autopilot engaged as the airplane descended through 10,000 feet mean sea level. The nose pitched down violently about 10 degrees, and then the nose pitched back up. The captain disengaged the autopilot and hand flew the airplane to touchdown. The Brasilia has two elevator trim actuators. The manufacturer discovered moisture and corrosion in some of the actuators submitted for repair after similar occurrences. They suspected that leaking seals allowed moisture into the actuators, which froze at altitude. In numerous instances, the actuators functioned properly after descent to lower altitudes and warmer temperatures, where the units thawed. One unit was dirty, corroded, and had overspray on it. It leaked from the shaft seals and autoloc seal. It failed the non-jamming stop test. It's two shaft housings contained moisture. The chain and pins were corroded, the packing had deteriorated, and the springs were weak. One side of the rollers was not chamfered, and staking warped some screws. The hub was worn and not functioning properly. The second unit was dirty and had overspray on it. The actuator leaked from the shaft seals. The actuator had excessive backlash and failed the tangential free play test. It's two shaft housings contained moisture. The chain, pins, shafts, and housings were corroded. The packing had deteriorated, and the bearings were rough and binding. The rollers only had one chamfered side. The shim was not with the unit.
NTSB Probable Cause Narrative
moisture contamination of the elevator trim actuators, which allowed the units to freeze at altitude resulting in an abrupt pitch change when the units thawed at lower altitudes.
Event Information
| Type of Event | Accident |
| Event Date | 2/25/2001 |
| Event Day of the Week | Sunday |
| Time of Event | 2155 |
| Event Time Zone | Pacific Standard Time |
| Event City | MONTEREY |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93940 |
| Event Date Year | 2001 |
| Event Date Month | 2 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 362500N |
| Event Location Longitude | 1215000W |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Full |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 2155 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | MRY |
| Elevation of weather observation facility | 121 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | PST |
| Lighting Conditions | Night |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 8 |
| Dew Point at event time (in degress fahrenheit) | 8 |
| Wind Direction (degrees magnetic) | 130 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 5 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29.98 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 32 |
| Injury Total Serious | 1 |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 15189 |
| NTSB Notification Source | Skywest Maintenance |
| NTSB Notification Date | Feb 26 2001 12:00AM |
| NTSB Notification Time | 1021 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Mar 30 2004 8:14AM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | WP-SJC-FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N288SW |
| NTSB Number | LAX01LA105 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Embraer |
| Aircraft Model | EMB-120 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 120316 |
| Certified Max Gross Weight | 26433 |
| 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 | 33 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Feb 21 2001 12:00AM |
| Airframe hours since last inspection | 35 |
| Airframe Hours | 11650 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Bank of America |
| Aircraft Owner Street Address | 555 California Street |
| Aircraft Owner City | San Francisco |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 94104 |
| Operator is an individual? | No |
| Operator Name | SKYWEST AIRLINES, INC. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 444 RIVER ROAD |
| Operator City | ST. GEORGE |
| Operator State | UT |
| Operator Country | USA |
| Operator Zip code | 84770 |
| Operator Code | SWIA |
| Owner has at least one certificate | -- |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| 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) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | LAX |
| Departure City | LOS ANGELES |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 2100 |
| Departure Time Zone | PST |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | MRY |
| Destination City | MONTEREY |
| Destination State | CA |
| Destination Country | USA |
| Specific Phase of Flight | Descent - normal |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Jan 17 2004 1:17PM |
| User who most recently changed record | COOS |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |