Atlantic Coast Airlines British Aerospace JETSTREAM 3201 JETSTREAM accident
British Aerospace JETSTREAM 3201 JETSTREAM · Accident: total loss of engine power (mechanical failure) en route
From Newport News Williamsburg International Airport (PHF) to Washington Dulles International Airport (IAD)
Event
- NTSB case
- IAD01FA006
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
British Aerospace JETSTREAM 3201 JETSTREAM
- Aircraft type
- British Aerospace JETSTREAM 3201
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N488UE
- Operator
- Atlantic Coast Airlines
- Onboard fatalities
- Unknown
- Route
- From Newport News Williamsburg International Airport (PHF), Newport News, VATo Washington Dulles International Airport (IAD), VA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · descent
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Total loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Manufacturer › Insufficient standards/requirements, manufacturer
- Reduction gear assembly, reduction gear › Separation
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
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.
Probable cause
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
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record IAD01FA006
- Event ID
- 20001212X22163
- Case number
- IAD01FA006
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: eba1310082fef70017607ca7bc6df5e24abecda7e5a7c89405260046d69f5623; retrieved 2026-09-18T16:21:44.904Z.