Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Miami, Florida
Wednesday, May 21, 2008 17:45 EST
NTSB Narrative Summary Released at Completion of Accident
The airplane’s No. 3 engine thrust reverser lost a large section of its inboard translating cowling (transcowl) after thrust reverser deployment at landing. A postincident inspection found that two of the three transcowl attachments (the lower and the center) had failed. The lower ballscrew actuator attachment had failed in fatigue at its rod end. The center (CDU) attachment had failed in overload at the clevis assembly bracket attachment rivets.
A fatigue analysis of the various rod ends qualified for use on CF6-80C2 series thrust reverser adjustable-length ballscrew actuators found that four of the 3/8-inch rod end part numbers (P/Ns), including P/N KBE6-59, which was on this thrust reverser, lacked sufficient predicted fatigue life.
A design validation of the CF6-80C2 thrust reverser actuating system (TRAS) found that TRAS end-of-stroke impact loads can induce torque loading at the rod ends and clevis assembly bracket attachment rivets that result in bending loads not accounted for in the original design. The design validation also found that the fatigue tolerance capability of the CDU clevis bracket attachment fasteners was marginal for the “one actuator out” (OAO) condition under normal deploy loads.
NTSB Probable Cause Narrative
The insufficient predicted fatigue life of the P/N KBE6-59 adjustable-length 3/8-inch rod end, and the inadequate fatigue margin at the transcowl CDU clevis assembly bracket attachment rivets for the one actuator out condition, which resulted in the failure of a second transcowl attachment during thrust reverser activation, leading to the partial liberation of the thrust reverser’s inboard transcowl.
Event Information
| Type of Event | Incident |
| Event Date | 5/21/2008 |
| Event Day of the Week | Wednesday |
| Time of Event | 1745 |
| Event Time Zone | Eastern Standard Time |
| Event City | Miami |
| Event State | FLORIDA |
| Event Country | -- |
| Zipcode of the event site | -- |
| Event Date Year | 2008 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | Yes |
| 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 | -- |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | -- |
| 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 | -- |
| 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 | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 31702 |
| NTSB Notification Source | Ashburn |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Aug 6 2013 9:18AM |
| User who most recently changed record | broda |
| Basic weather conditions | -- |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | EI-UPO |
| NTSB Number | ENG08IA027 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 129: Foreign |
| Type of Flight Plan filed | -- |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | MD-11F |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 48429 |
| 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 | 3 |
| 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 | Alitalia Airlines |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Rome |
| Aircraft Owner State | -- |
| Aircraft Owner Country | IT |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | Alitalia Airlines |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Rome |
| Operator State | -- |
| Operator Country | IT |
| 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 | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Scheduled |
| Indicates Domestic or International Flight | International |
| Operator carrying Pax/Cargo/Mail | Cargo |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | Yes |
| 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 | Landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jul 18 2012 9:53AM |
| User who most recently changed record | horc |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | -- |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |