Individually Owned: 150,657
Corporate Owned: 137,281
Anchorage Intl Airport
Aircraft Accident/Incident Report
Anchorage, Alaska 99502
Wednesday, March 31, 1993 12:34 AST
NTSB Narrative Summary Released at Completion of Accident
SHORTLY AFTER TAKEOFF FROM ANCHORAGE, THE AIRPLANE FLEW INTO AN AREA OF SEVERE TURBULENCE, WHILE CLIMBING THROUGH AN ALTITUDE OF ABOUT 2000 FEET. THE NUMBER 2 ENGINE AND ENGINE PYLON SEPARATED FROM THE AIRPLANE. THE FLIGHTCREW DECLARED AN EMERGENCY AND THE FLIGHT RETURN TO ANCHORAGE, WHERE AN UNEVENTFUL LANDING WAS ACCOMPLISHED. THE INVESTIGATION REVEALED THAT A STRONG EASTERLY WIND INTERACTED WITH MOUNTAINS EAST OF ANCHORAGE, WHICH PRODUCED MOUNTAIN WAVE ACTIVITY. THE AIRCRAFT ENCOUNTERED SEVERE OR POSSIBLY EXTREME TURBULENCE. THERE WAS EVIDENCE THAT THIS RESULTED IN DYNAMIC MULTI-AXIS LATERAL LOADINGS THAT EXCEEDED THE ULTIMATE LATERAL LOAD-CARRYING CAPABILITY OF THE NUMBER 2 ENGINE PYLON, WHICH HAD ALREADY BEEN REDUCED BY THE PRESENCE OF A FATIGUE CRACK NEAR THE FORWARD END OF THE PYLON'S FORWARD FIREWALL WEB.
NTSB Probable Cause Narrative
THE LATERAL SEPARATION OF THE NO. 2 ENGINE PYLON DUE TO AN ENCOUNTER WITH SEVERE OR POSSIBLY EXTREME TURBULENCE THAT RESULTED IN DYNAMIC MULTI-AXIS LATERAL LOADINGS THAT EXCEEDED THE ULTIMATE LATERAL LOAD-CARRYING CAPABILITY OF THE PYLON, WHICH WAS ALREADY REDUCED BY THE PRESENCE OF THE FATIGUE CRACK NEAR THE FORWARD END OF THE PYLON'S FORWARD FIREWALL WEB.
Event Information
| Type of Event | Accident |
| Event Date | 3/31/1993 |
| Event Day of the Week | Wednesday |
| Time of Event | 1234 |
| Event Time Zone | Atlantic Standard Time |
| Event City | ANCHORAGE |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99502 |
| Event Date Year | 1993 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | ANCHORAGE INTL |
| Event Location Nearest Airport ID | ANC |
| 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 | 144 |
| Weather Briefing Completeness | Full |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1156 Atlantic Standard Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | ANC |
| Elevation of weather observation facility | 144 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | AST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 8000 |
| Lowest Non-Ceiling Height | 8000 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 60 |
| Air Temperature at event time (in degrees celsius) | 9 |
| Dew Point at event time (in degress fahrenheit) | -6 |
| Wind Direction (degrees magnetic) | 90 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 7 |
| 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 | 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 | 5 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 797 |
| NTSB Notification Source | -- |
| NTSB Notification Date | -- |
| NTSB Notification Time | 0 |
| Fiche Number and/or location -used to find docket information | 48294 |
| Date of most recent change to record | Dec 11 2000 1:11PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N473EV |
| NTSB Number | DCA93MA033 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 129: Foreign |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 747-121 |
| Aircraft Series Identifier | 747-121 |
| Aircraft Serial Number | 19657 |
| Certified Max Gross Weight | 740000 |
| 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 | 5 |
| Number of Engines | 4 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Mar 3 1993 12:00AM |
| Airframe hours since last inspection | 48 |
| Airframe Hours | 18370 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | EVERGREEN INTERNATIONAL |
| Aircraft Owner Street Address | 3850 THREE MILE LANE |
| Aircraft Owner City | MCMINNVILLE |
| Aircraft Owner State | OR |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 97128 |
| Operator is an individual? | -- |
| Operator Name | JAPAN AIRLINES |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 9 1 HANEDA AIRPORT, OTA-KW |
| Operator City | TOKYO,JAPAN |
| Operator State | |
| Operator Country | |
| Operator Zip code | |
| Operator Code | |
| 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 | Cargo |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | ANC |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1230 |
| Departure Time Zone | AST |
| Destination Same as Local Flt | -- |
| Destination Airport Code | ORD |
| Destination City | CHICAGO |
| Destination State | IL |
| 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 | 6R |
| Runway Length | 10897 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |