SkyWest Airlines Flight 7915
Embraer EMB-120 · Accident: airframe, component or system failure en route
From Los Angeles International Airport (LAX) to Monterey Regional Airport (MRY)
Event
- NTSB case
- LAX01LA105
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Embraer EMB-120
- Aircraft type
- Embraer EMB-120
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N288SW
- Operator
- SkyWest Airlines
- Onboard fatalities
- Unknown
- Route
- From Los Angeles International Airport (LAX), Los Angeles, CATo Monterey Regional Airport (MRY), Monterey, CA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · descent
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Autopilot/flight director, servo › Contamination, water
- Autopilot/flight director, servo › Frozen
- Flt control syst, elevator trim/tab control › Hardover
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
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.
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX01LA105
- Event ID
- 20010307X00558
- Case number
- LAX01LA105
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: local date, investigation status, coordinates, damage. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2001-02-26.
- API snapshot SHA-256: e673a513f1a3157d4ffbb44570e501d871de7433ecdef30e75429a7843e43087; retrieved 2026-09-18T16:16:35.582Z.