Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Ontario, California 91761
Monday, April 4, 1994 18:15 PDT
NTSB Narrative Summary Released at Completion of Accident
The aircraft was climbing at 1,000 feet per minute to a cruising altitude of 21,000 feet. Passing 19,800 feet, a loud 'bang' was heard and the captain was partially sucked through the broken left side window. After about 4 seconds, he was able to pull himself back into the aircraft unassisted. He declared an emergency and landed the aircraft without further incident. A review of the maintenance records revealed that an applicable airworthiness directive requiring an inspection of the windows was complied with within the last 143.8 flight hours. The technical representative for Fairchild stated that maintenance personnel who conducted the AD inspection and service bulletin inspections may have failed to detect the crack, due to the subtle inspection procedures employed. The approved inspection procedures allow for two methods: 1) removal of the outer frame retainer for direct viewing of the screw holes, and 2) using a 90-degree prism seated in mineral oil for an indirect view of the screw holes. The airline was using the second method.
NTSB Probable Cause Narrative
the failure of maintenance personnel to detect a crack in the windscreen which exceeded the operational limits for pressurized flight. A factor in the accident was the inadequacy of the inspection method published by the manufacturer.
Event Information
| Type of Event | Incident |
| Event Date | 4/4/1994 |
| Event Day of the Week | Monday |
| Time of Event | 1815 |
| Event Time Zone | Pacific Daylight Time |
| Event City | ONTARIO |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 91761 |
| Event Date Year | 1994 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| 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 | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 146 GMT |
| Direction of event from weather observation facility (degrees) | 140 |
| Weather Observation Facility ID | ONT |
| Elevation of weather observation facility | 943 |
| Distance of event from weather observation facility (units?) | 53 |
| Time Zone of the weather observation | GMT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 20000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| 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) | 17 |
| Dew Point at event time (in degress fahrenheit) | 12 |
| Wind Direction (degrees magnetic) | 240 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 10 |
| 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 | Minor |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | 1 |
| Injury Total None | 11 |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5006 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 4 1994 12:00AM |
| NTSB Notification Time | 1930 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 6 2000 11:02AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N174SW |
| NTSB Number | LAX94IA181 |
| 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 | FAIRCHILD |
| Aircraft Model | SA-227AC |
| Aircraft Series Identifier | SA-227AC |
| Aircraft Serial Number | AC620 |
| Certified Max Gross Weight | 14500 |
| 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 | Apr 1 1994 12:00AM |
| Airframe hours since last inspection | 13 |
| Airframe Hours | 19936 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | PROVIDENT BANK TRUSTEE |
| Aircraft Owner Street Address | ONE EAST FOURTH STREET |
| Aircraft Owner City | CINCINNATI |
| Aircraft Owner State | OH |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 45202 |
| Operator is an individual? | -- |
| 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 S. RIVER ROAD |
| Operator City | ST GEORGE |
| Operator State | UT |
| Operator Country | |
| Operator Zip code | 84770 |
| Operator Code | SWIA |
| 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 | LAX |
| Departure City | LOS ANGELES |
| Departure State | CA |
| Departure Country | |
| Departure Time | 1750 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | YUM |
| Destination City | YUMA |
| Destination State | AZ |
| Destination Country | |
| Specific Phase of Flight | Climb |
| 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 | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |