Individually Owned: 150,657
Corporate Owned: 137,281
Douglas International Airport
Aircraft Accident/Incident Report
Charlotte (Clt), North Carolina
Sunday, October 28, 2007 9:48 EST
NTSB Narrative Summary Released at Completion of Accident
On October 28, 2007, a US Airways Boeing 757-200, N919UW, experienced a fracture of the truck beam on the left hand (LH) main landing gear (MLG) while preparing for departure from Charlotte/Douglas International Airport (CLT). The airplane was loaded with flight crew, cabin crew, passengers and cargo at the time of the truck beam failure. There was no other damage to the airplane and there were no injuries to any of the occupants or the ground personnel. The truck beam had accumulated 24,025 cycles since new and 2,707 cycles since its last overhaul which occurred in May, 2005.
The truck beam fracture initiated by fatigue and stress corrosion cracking from pits that were present on the ID surface of the truck beam, under the protective finishes. Crack propagation occurred by alternating modes of stress corrosion cracking and fatigue until final fracture occurred by ultimate ductile separation. The condition of the surface finishes and base metal at the fracture initiation area indicated that the pitting was present before the last application of cadmium plating and primer, rather than the result of corrosion since the last overhaul. The observed pitting appeared to be remnants of incomplete corrosion removal during the last overhaul. Residual stress analysis of the ID surface in the fracture initiation region suggested that the blended area did not receive adequate peening to restore typical residual compressive stresses. The observed reduction in residual compressive stresses likely contributed to the fracture initiation. The wall thickness at the area of fracture initiation measured 0.29” and was within drawing dimensional tolerances. Chemical analysis and hardness testing verified that the truck beam was fabricated from the required material in the specified heat treated condition. Evaluation of the protective finishes on the truck beam indicated that the cadmium plating on the ID surface did not meet the minimum thickness requirements.
NTSB Probable Cause Narrative
The truck beam fracture initiated by fatigue and stress corrosion cracking from pits that were present on the ID surface of the truck beam, under the protective finishes. Crack propagation occurred by alternating modes of stress corrosion cracking and fatigue until final fracture occurred by ultimate ductile separation. The condition of the surface finishes and base metal at the fracture initiation area indicated that the pitting was present before the last application of cadmium plating and primer, rather than the result of corrosion since the last overhaul. The observed pitting appeared to be remnants of incomplete corrosion removal during the last overhaul.
Event Information
| Type of Event | Incident |
| Event Date | 10/28/2007 |
| Event Day of the Week | Sunday |
| Time of Event | 948 |
| Event Time Zone | Eastern Standard Time |
| Event City | Charlotte (CLT) |
| Event State | NORTH CAROLINA |
| Event Country | -- |
| Zipcode of the event site | -- |
| Event Date Year | 2007 |
| Event Date Month | 10 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | Douglas International |
| Event Location Nearest Airport ID | CLT |
| 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 | -- |
| 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) | 28207 |
| NTSB Notification Source | US Airways |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Mar 31 2011 1:22PM |
| User who most recently changed record | murb |
| Basic weather conditions | -- |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N919UW |
| NTSB Number | ENG08IA001 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | Unknown |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 757-225 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 22198 |
| Certified Max Gross Weight | -- |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | 225 |
| 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 | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | U S BANK NA TRUSTEE |
| Aircraft Owner Street Address | CORPORATE TRUST SERVICES |
| Aircraft Owner City | BOSTON |
| Aircraft Owner State | MA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 02110 |
| Operator is an individual? | No |
| Operator Name | US AIRWAYS INC |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 4000 East Sky Harbor |
| Operator City | Phoenix |
| Operator State | AZ |
| Operator Country | USA |
| Operator Zip code | 85034 |
| Operator Code | USAA |
| 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 | USAA105A |
| 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) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | -- |
| Departure City | -- |
| Departure State | -- |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | -- |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Nov 17 2010 11:59AM |
| User who most recently changed record | murb |
| 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 | -- |