Individually Owned: 150,657
Corporate Owned: 137,281
Cincinnati International Airpo Airport
Aircraft Accident/Incident Report
Cincinnati (Cvg), Ohio 41048
Thursday, January 7, 2010 EST
NTSB Narrative Summary Released at Completion of Accident
On January 7, 2010 Astar Air Cargo reported that during of a DC-8-73 hydraulic fluid leaking from a small crack at the upper end of the nose landing gear (NLG) cylinder. The following day, during taxi to the maintenance hangar, a loud bang was heard after a turn. Further inspection revealed that the NLG cylinder had fractured. The NLG was overhauled in April 2007 by AAR Landing Gear Services (LGS) in Miami Florida. The NLG was installed on the incident airplane on January 5, 2010 and had accumulated one ground air ground (GAG) cycle prior to the failure. The NLG assembly was removed and replaced and the failed cylinder was submitted to the Boeing Huntington Beach Failure Analysis Laboratory for failure analysis. At the time of the incident it was reported that the airplane had accumulated 86,911 flight hours and 32,212 cycles.
The NLG cylinder failed due to intergranular (IG) cracking at the inner surface of the cylinder coincidental to a chrome plating crack, then propagated by stress corrosion cracking. The plating crack was determined to be cleavage fracture and could have occurred during the grinding of the chrome plating to size. The fracture surfaces of the primary and secondary crack, each exhibited a combination of dark gray and orange-brown discoloration that extended to 0.95 and 0.85 inches, respectively, and towards the outer surface of the cylinder. A short distance from the outer surface of the cylinder, there was no observable discoloration on the fracture surface of the primary crack. The discoloration indicated that the fracture occurred over an unknown period of time. Etch inspection of the inner surface of the cylinder revealed evidence of circumferential grinding burns. Light circumferential scratches were also observed however their origin could not be determined.
NTSB Probable Cause Narrative
Failure of the NLG cylinder occurred by intergranular rupture; coincidental to a chrome plating crack. The failure origin occurred along the inner surface of the cylinder and then propagated by stress corrosion cracking to the outer surface. A secondary crack with the same features as the primary crack was found diagonal to the primary crack. Both cracks initiated by intergranular cracking due to grinding burns caused by abusive grinding and propagated by stress corrosion cracking. Hydrogen embrittlement did not contribute to the intergranular cracking.
Event Information
| Type of Event | Incident |
| Event Date | 1/7/2010 |
| Event Day of the Week | Thursday |
| Time of Event | -- |
| Event Time Zone | Eastern Standard Time |
| Event City | Cincinnati (CVG) |
| Event State | OHIO |
| Event Country | -- |
| Zipcode of the event site | 41048 |
| Event Date Year | 2010 |
| Event Date Month | 1 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | Cincinnati International Airpo |
| Event Location Nearest Airport ID | CVG |
| 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) | 28210 |
| NTSB Notification Source | Federal Aviation Adnministrati |
| 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 1:56PM |
| User who most recently changed record | murb |
| Basic weather conditions | -- |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N803DH |
| NTSB Number | ENG10IA016 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | DOUGLAS |
| Aircraft Model | DC8 |
| Aircraft Series Identifier | 73F |
| Aircraft Serial Number | 46123 |
| Certified Max Gross Weight | 355000 |
| 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 | 4 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Jan 2 2010 12:00AM |
| Airframe hours since last inspection | 2 |
| Airframe Hours | 87107 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | WELLS FARGO BANK NORTHWEST NA TRUSTEE-DHL Express |
| Aircraft Owner Street Address | 299 S MAIN ST MAC U1228-120 |
| Aircraft Owner City | SALT LAKE CITY |
| Aircraft Owner State | UT |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 84111-2263 |
| Operator is an individual? | No |
| Operator Name | ASTAR AIR CARGO INC |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 1200 Brickell Avenue 16th Floor |
| Operator City | Miami |
| Operator State | FL |
| Operator Country | USA |
| Operator Zip code | 33131 |
| Operator Code | DHLA |
| 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 | DHLA895A |
| 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) | -- |
| Second Pilot on Board | -- |
| Departure Point Same as Event | No |
| Departure Airport Code | MIA |
| Departure City | -- |
| Departure State | -- |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | CVG |
| Destination City | Cincinnati |
| Destination State | OH |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Dec 22 2010 12:25PM |
| User who most recently changed record | murb |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |