LAX90LA029 · Bell-Kitz Kopters 47D1
Bell-Kitz Kopters 47D1 · Accident: airframe, component or system failure on approach
From Chino Airport (CNO) to Chino Airport (CNO)
Event
- NTSB case
- LAX90LA029
- 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-Kitz Kopters 47D1
- Aircraft type
- Bell Kitz Kopters 47
- 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
- N6324X
- Operator
- Petkow, Raymond · private individual
- Onboard fatalities
- Unknown
- Route
- From Chino Airport (CNO)To Chino Airport (CNO)
- 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 · VFR pattern downwind
- 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
- Company maintenance personnel › Maintenance, inspection, inadequate
- Company maintenance personnel › Maintenance, installation, intentional
- Rotor system › Unapproved part
- Rotor system, stabilizer bar › Bent
- Rotor system, stabilizer bar › Failure, total
- Rotor system, stabilizer bar › Fatigue
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE STUDENT PILOT WAS PRACTICING TOUCH AND GO TAKEOFFS AND LANDINGS. WHILE ON THE DOWNWIND LEG THE STUDENT PILOT RPTD THAT THE HELICOPTER BEGAN TO VIBRATE AND THEN VIOLENTLY PITCHED UP. THE STUDENT PILOT IMMEDIATELY EXECUTED AN AUTOROTATION INTO A COW PASTURE. THE WRECKAGE EXAM DSCLSD THE MAIN ROTOR STABILIZER BAR SEPARATED IN FLT AND IT WAS NOT FOUND. THE ATTACH SECTION OF THE BAR REMAINED CONNECTED AT ITS ATTACH POINTS. METALLURGICAL EXAM DSCLSD THE INNER BAR AND THE TIE ROD FRACTURED IN FATIGUE WHICH HAD PROPAGATED VERY SLOWLY, AND CRACKS WOULD HAVE BEEN EVIDENT. BELL HELICOPTER HAD ISSUED SERVICE BULLETIN 47-(04-2)73-1 REQUIRING DAILY INSPECTION OF THE BAR FOR CRACKS. THE TIE ROD NUT WAS A BOGUS PART AND EXCESSIVELY WORN.
Probable cause
A FATIGUE FAILURE OF BOTH THE MAIN ROTOR STABILIZER BAR TUBE AND THE TIE ROD. IN ADDITION, THE TIE ROD NUT WAS LOOSE AND DID NOT CONFORM TO ENGINEERING DRAWING SPECIFICATIONS. COMPANY PERSONNEL FAILED TO DETECT THE FATIGUE CRACKS DURING DAILY INSPECTIONS.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX90LA029
- Event ID
- 20001213X29821
- Case number
- LAX90LA029
- 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: e1ad7ee5d40355833bb7e6dfb080632e7d89d342e6d1e376846fc83666288c77; retrieved 2026-09-23T07:00:01.954Z.