Individually Owned: 150,657
Corporate Owned: 137,281
Los Angeles International Airp Airport
Aircraft Accident/Incident Report
Los Angeles, California 90009
Sunday, June 12, 2005 22:26 PDT
NTSB Narrative Summary Released at Completion of Accident
The airplane was damaged during a landing with the nose landing gear partially extended. As the airplane descended toward the destination airport, the crew moved the landing gear handle to the extend position. The pilots noted a "gear disagree" warning message displayed on the Engine Indicating and Crew Alerting System (EICAS) that showed the main landing gear were down and locked, and the nose gear was not fully extended. The pilots opted to land at an alternate airport and began to troubleshoot the gear indication with use of the airplane's Quick Reference Handbook (QRH). Despite their efforts, which included using the manual release handle, the nose gear failed to extend. The airplane touched down on the main landing gear and the nose lowered to the ground as the speed dissipated. Review of the CVR found that the flight crew followed each step of the Quick Reference Handbook checklist. The flight crew did not cycle the landing gear lever, nor was that action part of the QRH procedure at the time. The digital flight data recorder (DFDR) revealed that the main landing gear transitioned into the down and locked position but the nose gear remained partially extended between the uplocked and downlocked positions. A further review of the data disclosed the hydraulic pressure remained constant throughout the extension and did not show the pressure changes that should have occurred with normal system operation. The only pressure changes noted in the duration of the flight were consistent with the manual release system being activated. No increase of brake pressure was recorded during the gear extension attempt, indicating that there was no hydraulic backpressure on the retract side of the NLG actuator. The components of the nose landing gear (NLG) system were tested, revealing no anomalies or malfunctions that could have precluded normal operation. Several simulations were conducted exploring various potential problem scenarios; however, none of the simulations produced the hydraulic system and brake pressure readings on the accident flight's DFDR data. A review of several maintenance discrepancy databases for events where the NLG failed to extend into the downlock position found that the operator did not have a higher event rate of gear disagree messages than the rest of the worldwide fleet. Simulations and static analysis on the friction force of the uplock was performed, specifically detailing the interaction between the pin and the latch. As a result of the testing, areas of potential problems with the NLG extension systems (both normal and manual) under adverse conditions were found to include: friction within the system and the sequencing of the hydraulic pressure application. Bombardier subsequently modified the QRH procedure, adding another step to specifically recycle the gear selector handle.
NTSB Probable Cause Narrative
failure of the nose landing gear to extend to the down and locked position for undetermined reasons.
Event Information
| Type of Event | Accident |
| Event Date | 6/12/2005 |
| Event Day of the Week | Sunday |
| Time of Event | 2226 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Los Angeles |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 90009 |
| Event Date Year | 2005 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 335633N |
| Event Location Longitude | 1182429W |
| Event Location Airport | Los Angeles International Airp |
| Event Location Nearest Airport ID | LAX |
| 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 | 126 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 2250 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | LAX |
| Elevation of weather observation facility | 126 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Night |
| Lowest Ceiling Height | 900 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 6 |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | 14 |
| Wind Direction (degrees magnetic) | 260 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.92 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 17 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 20639 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Jun 12 2005 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Nov 29 2006 12:45PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | WP-LAX-FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N960SW |
| NTSB Number | LAX05FA202 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Bombardier Aerospace, Inc. |
| Aircraft Model | CL-600-2B19 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 7845 |
| Certified Max Gross Weight | 54000 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 53 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Apr 1 2005 12:00AM |
| Airframe hours since last inspection | 342.5 |
| Airframe Hours | 4126.6 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | SKYWEST AIRLINES INC |
| Aircraft Owner Street Address | 444 South River Road |
| Aircraft Owner City | St. George |
| Aircraft Owner State | UT |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 84790 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| 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 | 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 | Yes |
| Departure Airport Code | LAX |
| Departure City | Los Angeles |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 2127 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | SBA |
| Destination City | Santa Barbara |
| Destination State | CA |
| Destination Country | USA |
| Specific Phase of Flight | Landing - roll |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Sep 26 2006 5:23PM |
| User who most recently changed record | COOS |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 25L |
| Runway Length | 11096 |
| Runway Width | 200 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |