NYC94IA023 · Bell 206L
Bell 206L · Incident: total loss of engine power (mechanical failure) en route
Event
- NTSB case
- NYC94IA023
- 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
- Incident
- 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
Bell 206L
- Aircraft type
- Bell 206
- 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
- N16696
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- 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
- En route · cruise
- 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
- None
Cause areas
- Company maintenance personnel › Maintenance, alignment, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE HELICOPTER WAS ON A LOCAL SIGHTSEEING FLIGHT AND OVER THE EAST RIVER IN NEW YORK CITY WHEN THERE WAS A LOSS OF ENGINE POWER. THE PILOT DEPLOYED THE EMERGENCY FLOATS, INITIATED AN AUTOROTATION AND LANDED ON THE RIVER. EXAMINATION OF THE ENGINE FOUND AN 'O' RING WAS IN AN IMPROPER POSITION ON THE TURBINE SPLINED ADAPTER WHICH CONNECTS THE TURBINE AND COMPRESSOR SECTIONS OF THE ENGINE. IN ADDITION, THE SPLINED END WAS DRY OF LUBRICATION AND WORN TO THE POINT OF DISENGAGEMENT BETWEEN THE COMPRESSOR AND TURBINE. ACCORDING TO THE FAA, DURING ENGINE ASSEMBLY, THE 'O' RING IS INSTALLED AND CHECKED TO SEE THAT IT IS IN THE PROPER POSITION, THEN THE ENGINE HALVES ARE ASSEMBLED. DURING THE ASSEMBLY, WHEN THE 'O' RING IS NO LONGER VISIBLE IT COULD BE ROLLED OUT OF POSITION OR DAMAGED. THIS COULD PREVENT LUBRICATION FROM REACHING THE SPLINED END.
Probable cause
Inadequate maintenance which resulted in the improper alignment of the 'O' ring on the spur adapter gear drive which caused lack of lubrication and wear of the gear drive and the disengagement of the compressor and turbine.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC94IA023
- Event ID
- 20001211X13629
- Case number
- NYC94IA023
- 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, damage. 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: d898cf65b361cff5c36be4054cfdce7e16e18be57810fa090fe8e79be22dd739; retrieved 2026-09-23T01:30:27.015Z.