SEA00LA097 · Bell 212
Bell 212 · Accident: airframe, component or system failure while maneuvering
From Eugene Airport (EUG) to an unrecorded destination
Event
- NTSB case
- SEA00LA097
- 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
Bell 212
- Aircraft type
- Bell 212
- 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
- CFHDY
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Eugene Airport (EUG)To 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
- Maneuvering · hover
- 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
- Manufacturer › Inadequate quality control
- Miscellaneous, bolt/nut/fastener/clamp/spring › Failure, total
- Rotor system, tail rotor blade balance weights › Separation
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During a practice power recovery autorotation to a hover, at about 600 feet AGL, the two pilots heard a loud bang, followed by a severe vibration. The PIC lowered the collective and rolled both throttles off to continue the autorotation to the ground, which landed without further incident. Inspection of the helicopter revealed that the 90-degree gearbox with tail rotors attached had separated from the tail boom. Inspection of the tail rotors revealed that the tip weight in one of the blades was missing. Examination of the blade revealed evidence of adhesive debonding between the adhesive and the spar surface. As a secondary securing method, four countersunk screws are in line chordwise and offset in pairs on each side of the blade. All four screw holes showed no significant evidence of deformation. It was determined that the four countersunk screws were ineffective due to the limited amount of clamping provided by the machining, at the manufacturer, of too large a diameter in the countersunk hole relative to the diameter of the screw head, thus allowing the four secondary load path screws to slip behind the spar, resulting in the tip block separating from the blade. The manufacturer reported that although the bonding adhesive is identified as the primary securing method for the tip block, and the four countersunk screws as the secondary, either method independent of the other is capable of carrying the load.
Probable cause
Inadequate quality control by the manufacturer during the manufacturing process, which led to the total failure of a fastener, and the separation of the tail rotor blade balance weight. An adhesive debond between the adhesive and the surface was a factor.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA00LA097
- Event ID
- 20001212X21328
- Case number
- SEA00LA097
- 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: 5abfbec3c7c026345425ff2708aac9e016e335d207857e55c1ee4adf851563bd; retrieved 2026-09-22T12:50:34.612Z.