Individually Owned: 150,657
Corporate Owned: 137,281
Los Angeles Airport
Aircraft Accident/Incident Report
Los Angeles, California
Friday, June 2, 2006 12:27 PDT
NTSB Narrative Summary Released at Completion of Accident
The Boeing 767 was undergoing a high-power test of the left-hand General Electric (GE) CF6-80C2 engine to troubleshoot a pilot's report of the engine being unable to make climb thrust. During the test, the engine experienced an uncontained failure of the high pressure turbine (HPT) stage 1 disk. Examination of the pieces of the disk revealed the disk failed from an intergranular fatigue crack that originated from a small depression on the blade slot bottom aft corner radius. There were two other intergranular fatigue cracks that originated from small depressions on other blade slot bottom aft corner radii. Intergranular fatigue cracks are typically associated with very high stresses that exceed the material's capability. GE issued service bulletins (SB) to require inspections of CF6-80A and -80C2 HPT stage 1 disks that the FAA mandated with airworthiness directives (AD), but the SBs and AD did not establish a compliance schedule. When the SBs and AD was revised to establish a compliance schedule, the schedule was such that disks with much higher cycles since new, than those that had previously failed or were found cracked, were permitted to remain in service. On August 26, 2006, the Safety Board issued safety recommendation A-06-60 through A-06-64, which addressed these deficiencies. The recommendations can be found at the following url address: http://www.ntsb.gov/recs/letters/2006/A06_60_64.pdf.
NTSB Probable Cause Narrative
The HPT stage 1 disk failed from an intergranular fatigue crack because of GE's inadequate design of the CF6-80 series HPT stage 1 disk. The inadequate design of the disk resulted in a high stress area in the blade slot bottom aft corner that was at or nearly at the material's capability so that there was no damage tolerance such that a small dent could cause a crack to initiate and propagate to failure. Contributing to the disk's failure was the FAA's failure to mandate an accelerated inspection schedule after a previous CF6-80A uncontained HPT stage 1 disk failure had occurred and after other CF6-80A HPT disks had been found during routine overhaul to have cracks in the blade slot bottom aft corners.
Event Information
| Type of Event | Incident |
| Event Date | 6/2/2006 |
| Event Day of the Week | Friday |
| Time of Event | 1227 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Los Angeles |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | -- |
| Event Date Year | 2006 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | Los Angeles |
| Event Location Nearest Airport ID | KLAX |
| 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 | -- |
| 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 | -- |
| 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 | Unknown |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| 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 | 3 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 22987 |
| NTSB Notification Source | NTSB LAX office |
| NTSB Notification Date | Jun 2 2006 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jan 30 2008 4:08PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | -- |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N330AA |
| NTSB Number | ENG06IA018 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Unknown |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | Ground |
| Aircraft Explosion | Ground |
| Aircraft Manufacturer's Full Name | Boeing |
| Aircraft Model | 767-223(ER) |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 22330 |
| Certified Max Gross Weight | 350000 |
| 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 | 167 |
| 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 | -- |
| ELT Activated | -- |
| ELT Aided Location of Event Site | -- |
| ELT Type | -- |
| Aircraft Owner Name | -- |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | -- |
| Aircraft Owner State | -- |
| Aircraft Owner Country | -- |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | -- |
| Operator Name | AMERICAN AIRLINES INC |
| Operator Same as Owner? | -- |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | -- |
| Operator Street Address | PO Box 619616 |
| Operator City | DallasFt Worth Airport |
| Operator State | TX |
| Operator Country | USA |
| Operator Zip code | 75261 |
| Operator Code | AALA |
| 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 | Non-scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | -- |
| Departure Point Same as Event | No |
| Departure Airport Code | -- |
| Departure City | -- |
| Departure State | -- |
| Departure Country | -- |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | -- |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Standing - engine(s) operating |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 11 2008 9:41AM |
| User who most recently changed record | defc |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |