Individually Owned: 150,657
Corporate Owned: 137,281
N/A Airport
Aircraft Accident/Incident Report
Ugolny Airport
Tuesady, July 2, 2013 10:26
NTSB Narrative Summary Released at Completion of Accident
On July 2, 2013, a Korean Air Lines (KAL) Boeing 777-300ER, registration number HL8275, powered by two General Electric (GE) GE90-115B turbofan engines, experienced a No. 1 engine (left) in-flight shutdown (IFSD) while crossing the Bering Sea. The pilots diverted the airplane to Ugolny Airport (DYR), in Siberia, Russia where an uneventful single engine landing was made. The Korean ARAIB requested delegation of the investigation and the NTSB accepted responsibility for investigating this incident. Post landing examination of the No. 1 engine revealed that the radial gearshaft within the transfer gearbox housing was fractured. Metallurgical examination of the radial gearshaft found an 0.049-inch axial crack with striation features indicative of fatigue propagation and a morphology consistent with initial fatigue initiation occurring under a torsional and/or biaxial stress condition. This axial crack was considered the primary crack and the fracture origin area. Microhardness tests near the fracture origin revealed a reduction in near surface hardness (lower hardness values than required). GE concluded that the near surface low hardness was attributable to decarburization due to marginal (thin or detached) copper plating existing on the gearshaft surface during the hardening process. Through computer modeling and testing of the radial gearshaft, GE concluded that the initiation of the axial crack was likely the result of a combination of high residual tensile stresses produced by local decarburization coupled with the operating stresses experienced at the outer diameter surface. To address the manufacturing process deficiency, GE issued seven service bulletins to remove, inspect, and repair the suspect radial gearshafts. To expedite the removal of the suspect radial gearshafts, the Federal Aviation Administration issued three separate Airworthiness Directives (AD). According to GE, all affected radial gearshafts addressed by the various FAA ADs have been removed from service.
NTSB Probable Cause Narrative
The failure of the transfer gearbox resulting from the fracture and separation of the radial gearshaft from fatigue cracking as a result of a combination of high residual tensile stresses produced by local decarburization during the manufacturing process coupled with the normal operating stresses.
Event Information
| Type of Event | Incident |
| Event Date | 7/2/2013 |
| Event Day of the Week | Tuesday |
| Time of Event | 1026 |
| Event Time Zone | -- |
| Event City | Ugolny Airport |
| Event State | -- |
| Event Country | -- |
| Zipcode of the event site | 00000 |
| Event Date Year | 2013 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 600416N |
| Event Location Longitude | 1784034W |
| Event Location Airport | N/A |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | -- |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Unknown |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Not Reported |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | -- |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | -- |
| Air Temperature at event time (in degrees celsius) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | -- |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | -- |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 32622 |
| NTSB Notification Source | Korean ARAIB |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | May 5 2014 2:59PM |
| User who most recently changed record | scaj |
| Basic weather conditions | Unknown |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | HL8275 |
| NTSB Number | ENG13IA033 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 129: Foreign |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 777 |
| Aircraft Series Identifier | 300ER |
| Aircraft Serial Number | 37651 |
| Certified Max Gross Weight | -- |
| 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 | -- |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Unknown |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | KE Export Leasing (2013-B) |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Seoul |
| Aircraft Owner State | FN |
| Aircraft Owner Country | KS |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | KOREAN AIR LINES COMPANY LTD |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 1370, Gonghang-dong |
| Operator City | Gangseo-gu, Seoul |
| Operator State | FN |
| Operator Country | KS |
| Operator Zip code | -- |
| Operator Code | KALF |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | KALF462F |
| Indicates whether an air carrier operation was scheduled or not | Scheduled |
| Indicates Domestic or International Flight | International |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | ORD |
| Departure City | Chicago |
| Departure State | IL |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | -- |
| Destination Airport Code | ICN |
| Destination City | Seoul |
| Destination State | FN |
| Destination Country | KS |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | May 5 2014 2:58PM |
| User who most recently changed record | scaj |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |