Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Los Angeles, California 90045
Tuesady, June 8, 1993 10:59 PDT
NTSB Narrative Summary Released at Completion of Accident
The aircraft was climbing through 25,000 feet in light turbulence when the crew felt two jolts and heard a loud explosive noise followed by a sharp roll to the left. A visual inspection revealed that the left overwing emergency escape slide deployed and separated in flight. The crew returned to Los Angeles and made an uneventful landing. Post incident examination revealed that the slide compartment door was unlatched and open, and, the adjacent maintenance access door was open, with the latching handle in the unlocked position. The flight prior to the incident one had experienced two EICAS warning messages concerning the left overwing slide door. After landing, maintenance personnel accessed the compartment, cleaned a proximity switch then functionally tested the system. The flight was then dispatched with no open items. The maintenance closing procedure in effect at the time of the incident called for one mechanic to hold the bottom corners of the 33 inch wide slide door closed while manipulating the latching handle in a maintenance access door 12 inches aft of the slide door. The procedure has since been changed to require two mechanics, one to hold the door closed while the second manipulates the latching handle.
NTSB Probable Cause Narrative
the inadvertent deployment of an overwing emergency excape slide due to the inadequate latching of the slide compartment door following access by maintenance personnel. A factor in the accident was the inadequate door closing procedure specified by the manufacturer and the airline in the maintenance instructions.
Event Information
| Type of Event | Incident |
| Event Date | 6/8/1993 |
| Event Day of the Week | Tuesday |
| Time of Event | 1059 |
| Event Time Zone | Pacific Daylight Time |
| Event City | LOS ANGELES |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 90045 |
| Event Date Year | 1993 |
| Event Date Month | 6 |
| 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 | Pilot |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 50 |
| Air Temperature at event time (in degrees celsius) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 197 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 5028 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jun 8 1993 12:00AM |
| NTSB Notification Time | 1115 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 18 2002 11:28AM |
| User who most recently changed record | NTSB\GIUV |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N540UA |
| NTSB Number | LAX93IA245 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 757-222 |
| Aircraft Series Identifier | 757-222 |
| Aircraft Serial Number | 25252 |
| Certified Max Gross Weight | 230000 |
| 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 | 197 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | May 17 1993 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | WILMINGTON TRUST CO. TRUSTEE |
| Aircraft Owner Street Address | RODNEY SQ. N. ATTN. CORP. TRST |
| Aircraft Owner City | WILMINGTON |
| Aircraft Owner State | DE |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 19890 |
| Operator is an individual? | -- |
| Operator Name | UNITED AIRLINES |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | EXOFS P.O.BOX 66100 |
| Operator City | CHICAGO |
| Operator State | IL |
| Operator Country | |
| Operator Zip code | 60666 |
| Operator Code | UALA |
| 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 | Yes |
| Departure Airport Code | |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1020 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | DEN |
| Destination City | DENVER |
| Destination State | CO |
| 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 | -- |