Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Dulles, Virginia 20116
Friday, October 20, 2000 17:00 EDT
NTSB Narrative Summary Released at Completion of Accident
The airplane was on the arrival to the destination airport, and was cleared to descend from 8,000 feet to 5,000 feet. A descent was initiated by reducing power on both engines. As the airplane descended through 6,500 feet, the crew heard a loud bang, followed by a vibration, and illumination of the right engine 'FIRE' warning light. The right engine RPM dropped to 80 percent and stabilized at that value. The fire bell also sounded. The crew identified the right engine, discharged fire bottle, and the 'FIRE' warning light extinguished. The engine was secured and the airplane landed uneventfully at IAD. Examination of the airplane revealed that the right engine bullgear experienced an uncontained separation in flight. A 4 5/8-inch long section of the bullgear rim penetrated the right side of the fuselage and was recovered from the left side interior cabin wall above seat 1A's seat cushion. Examination of the right engine gearbox revealed that the bull gear was broken into at least six pieces. The gearbox diaphragm's bull gear bearing bore was measured and found to be over the engine manual's allowable wear limit. The engine's maintenance records show that the bull gear was installed new at the last repair, 597 hours and 776 cycles before the event. Metallurgical examination of the bull gear revealed an initial fatigue fracture that originated on the front face of the bull gear outboard of the hub. There were two other fatigue fractures that were on either side of the initial fatigue fracture. The examination also revealed that the bull gear's web thickness and material hardness conformed to the manufacturer's design requirements. As a result of this investigation, the FAA was considering an airworthiness directive that would require a recurring sampling of oil to be analyzed for increased levels of metal that could be indicative to bull and high speed pinion gear wear.
NTSB Probable Cause Narrative
The manufacturer's lack of dimensional inspection and repair requirements for the gearbox forward and aft diaphragm, which caused the bull gear to shift and resulted in an uncontained separation of the bull gear during flight
Event Information
| Type of Event | Accident |
| Event Date | 10/20/2000 |
| Event Day of the Week | Friday |
| Time of Event | 1700 |
| Event Time Zone | Eastern Daylight Time |
| Event City | DULLES |
| Event State | VIRGINIA |
| Event Country | -- |
| Zipcode of the event site | 20116 |
| Event Date Year | 2000 |
| Event Date Month | 10 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| 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 | Unknown |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1651 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 190 |
| Weather Observation Facility ID | IAD |
| Elevation of weather observation facility | 313 |
| Distance of event from weather observation facility (units?) | 30 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Night/Dark |
| 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) | 21 |
| Dew Point at event time (in degress fahrenheit) | 5 |
| Wind Direction (degrees magnetic) | 170 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 6 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | 1041 |
| 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 | 12 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 11208 |
| NTSB Notification Source | EASTERN REGION |
| NTSB Notification Date | Oct 20 2000 12:00AM |
| NTSB Notification Time | 1720 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 18 2001 1:05PM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N488UE |
| NTSB Number | IAD01FA006 |
| 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 | In-flight |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | British Aerospace |
| Aircraft Model | JETSTREAM 3201 |
| Aircraft Series Identifier | JETSTREAM |
| Aircraft Serial Number | 907 |
| Certified Max Gross Weight | 16204 |
| 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 | 19 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Oct 6 2000 12:00AM |
| Airframe hours since last inspection | 84 |
| Airframe Hours | 22911 |
| ELT Installed | Yes |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | FIRST SECURITY BANK NA-TRUSTEE |
| Aircraft Owner Street Address | |
| Aircraft Owner City | SALT LAKE CITY |
| Aircraft Owner State | UT |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 84111 |
| Operator is an individual? | -- |
| Operator Name | ATLANTIC COAST AIRLINES |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | |
| Operator City | DULLES |
| Operator State | VA |
| Operator Country | |
| Operator Zip code | 20166 |
| Operator Code | VTZA |
| 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 | No |
| Departure Airport Code | PHF |
| Departure City | NEWPORT NEWS |
| Departure State | VA |
| Departure Country | |
| Departure Time | 1632 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | IAD |
| Destination City | |
| Destination State | VA |
| Destination Country | |
| Specific Phase of Flight | Descent |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jun 10 2001 4:02AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |