ATL82DA100 · S.N.I.A.S. AS350D ASTAR AS350D AST
Mountain Coals S.N.I.A.S. AS350D ASTAR AS350D AST · Accident: airframe, component or system failure on approach
From MIDDESBORO, KY to Alcoa, TN
Event
- NTSB case
- ATL82DA100
- 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
- General aviation
- 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
S.N.I.A.S. AS350D ASTAR AS350D AST
- Aircraft type
- S AS350
- Category
- Helicopter
- 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
- N3605B
- Operator
- Mountain Coals
- Onboard fatalities
- Unknown
- Route
- From MIDDESBORO, KYTo Alcoa, TN
- 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 91: General Aviation
- 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
- Approach
- 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
- Airframe, component or system 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
- Rotor drive system, tail rotor drive shaft bearing › Binding(mechanical)
- Rotor drive system, tail rotor drive shaft › Failure, total
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
WHILE PREPARING TO LAND, THE PILOT EXPERIENCED A TAIL ROTOR DRIVE FAILURE AT A SPEED OF LESS THAN 60 KNOTS. AT THAT SPEED, HE WAS UNABLE TO MAKE THE NECESSARY RIGHT TURN FROM HIS POSITION TO LAND ON THE RUNWAY. INSTEAD, HE CLIMBED ABOUT 50 FT IN A LEFT TURN TO LINE-UP FOR A RUN-ON LANDING. AS HE SLOWED TO ABOUT 20 KNOTS AT LOW ALTITUDE, THE HELICOPTER BEGAN TO YAW HARD TO THE LEFT. THE COLLECTIVE WAS LOWERED TO TOUCHDOWN BEFORE CONTROL WAS LOST. DURING THE LANDING, THE HELICOPTER BOUNCED AND ROTATED ABOUT 90 DEGREES BEFORE COMING TO REST. AN EXAMINATION REVEALED THAT THE NUMBER 4 TAIL ROTOR DRIVE SHAFT BEARING, PN 6007-2RS1MT47CA, HAD SEIZED. THE TAIL ROTOR DRIVE SHAFT AND RUBBER MOUNTING COLLAR CONTINUED TURNING UNTIL THE SEIZED BEARING CHAFFED THROUGH THE COLLAR AND ALSO THE DRIVE SHAFT ITSELF. SUBSEQUENTLY, THE TAIL ROTOR DRIVE SHAFT, PN 350A34-0110-02, SHEARED. THE TAIL ROTOR DRIVE SHAFT BEARING WAS FACTORY LUBED AND SEALED AND HAD NO RETIREMENT TIME LIMIT. THE BEARING FAILED AFTER 729 HOURS OF OPERATION.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record ATL82DA100
- Event ID
- 20020917X01700
- Case number
- ATL82DA100
- 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 UTC date the NTSB stores; the local time zone is not recorded, so the local date may differ by a day.
- API snapshot SHA-256: 9e84775636549f61f6287d576caa473c4025af801b740bc09abba0f81555d310; retrieved 2026-09-22T03:07:42.084Z.