Individually Owned: 150,657
Corporate Owned: 137,281
Dfw International Airport
Aircraft Accident/Incident Report
Dfw Airport, Texas 75261
Monday, July 1, 1996 7:11 CDT
NTSB Narrative Summary Released at Completion of Accident
The airplane departed runway 13L and climbed to an altitude of approximately 400 feet AGL when the flight crew 'heard a loud bang.' The right engine upper cowling departed the airplane, the right engine shut itself down, and the right propeller automatically feathered. The flight crew declared an emergency and executed a single engine landing without further incident. Examination of the airplane's right CT7-9B turboprop engine revealed that the Stage 2 turbine disk was missing and that approximately one third of the disk was found in the right landing light compartment. One end of the disk fragment progressed through a cooling air hole and there was evidence of a fatigue fracture that had initiated from multiple origins on the inboard side of the cooling air hole. Research revealed a layer of deformed microstructure and an associated zone of increased disk hardness near the origin area of the fatigue crack. Test disks were drilled using dull and worn drill bits which resulted in plastic deformation and increased hardness of the inner diameter hole surfaces. The manufacturer reported that the deformed microstructure correlates to a zone of reduced fatigue properties.
NTSB Probable Cause Narrative
The manufacturer's inadequate procedure for manufacturing the number two turbine disk.
Event Information
| Type of Event | Accident |
| Event Date | 7/1/1996 |
| Event Day of the Week | Monday |
| Time of Event | 711 |
| Event Time Zone | Central Daylight Time |
| Event City | DFW AIRPORT |
| Event State | TEXAS |
| Event Country | -- |
| Zipcode of the event site | 75261 |
| Event Date Year | 1996 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | DFW INTERNATIONAL AIRPORT |
| Event Location Nearest Airport ID | DFW |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 4 |
| Degrees magnetic from airport | 90 |
| Airport Elevation | 603 |
| Weather Briefing Completeness | Full |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 653 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 270 |
| Weather Observation Facility ID | KDF |
| Elevation of weather observation facility | 603 |
| Distance of event from weather observation facility (units?) | 4 |
| Time Zone of the weather observation | CDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 25 |
| Dew Point at event time (in degress fahrenheit) | 18 |
| Wind Direction (degrees magnetic) | 180 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 9 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 15 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1812 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 1 1996 12:00AM |
| NTSB Notification Time | 1200 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 10:11AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N335AE |
| NTSB Number | FTW96FA282 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Saab-Scania AB (Saab) |
| Aircraft Model | SF340B |
| Aircraft Series Identifier | SF340B |
| Aircraft Serial Number | 340B-335 |
| Certified Max Gross Weight | 29000 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 27 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Jun 12 1996 12:00AM |
| Airframe hours since last inspection | 121 |
| Airframe Hours | 6501 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | AMR LEASING CORPORATION |
| Aircraft Owner Street Address | P.O. BOX 619616 MD 5661 |
| Aircraft Owner City | DFW AIRPORT |
| Aircraft Owner State | TX |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 75261 |
| Operator is an individual? | -- |
| Operator Name | WINGS WEST AIRLINES, INC. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 835 AIRPORT DRIVE |
| Operator City | SAN LUIS OBISPO |
| Operator State | CA |
| Operator Country | |
| Operator Zip code | 93401 |
| Operator Code | WWMA |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| 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) | Unknown |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | DFW |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 711 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | SHV |
| Destination City | SHREVEPORT |
| Destination State | LA |
| Destination Country | |
| Specific Phase of Flight | Takeoff |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 13L |
| Runway Length | 9000 |
| Runway Width | 200 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |