# Accident 19980606012499A: Snias AS350B, Burbank, CA, June 6, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 6, 1998, 00:25 local time
- Place: Burbank, CA
- Damage: Substantial damage
- Phase of flight: Normal Cruise
- Operating rules: General operating rules (Part 91)
- Operator: KVNA
- Location: 34.1901° N, 118.3264° W: Placed by OpenAirDocs: center of Burbank, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=34.1901&lon=-118.3264&mi=10
- Aircraft: N31621 (not matched to a registry record)
- Reported make and model: SNIAS AS350B
- Reported engine: TMECA ARRIEL1B
- People aboard: 1
- Fatal injuries: 0
- Pilot flight hours: 9,000 total, 50 in this make and model, 40 in the last 90 days
- NTSB investigation: [NTSB LAX98LA184](https://openairdocs.org/ntsb/LAX98LA184) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19980606012499A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

VIBRATIONS PITCHING AND YAWING BEGAN. GEAR BOX LIGHT ON. LANDED ON A PARKING GARAGE ROOF. TAILBOOM HAD BROKEN OFF. (.4)THE PILOT FELT A 'VIOLENT VIBRATION' AND THE HELICOPTER BEGAN TO PITCH AND YAW.  ABOUT 5 SECONDS AFTER THE VIBRATION STARTED, THE TAIL ROTOR GEARBOX CHIP LIGHT BECAME ILLUMINATED.  THE PILOT MADE A NORMAL APPROACH TO A ROOFTOP PARKING STRUCTURE AND LANDED.  THE LAST 3 FEET OF THE TAIL BOOM HAD SEPARATED 360 DEGREES IN CIRCUMFERENCE.  EXAMINATION OF THE TAIL ROTOR SYSTEM REVEALED ONE PITCH CHANGE LINK DISCONNECTED DUE TO A FATIGUE FRACTURE, WHICH EMANATED FROM MULTIPLE ORIGINS AT THE INSIDE DIAMETER SURFACE OF THE LOOP THAT IS IN CONTACT WITH THE BEARING ASSEMBLY.  THE SCRIM CLOTH FOR THE BEARING ASSEMBLY RACEWAY WAS MISSING, AND THE BEARING OUTER RACEWAY CONTAINED WEAR DAMAGE APPROXIMATELY 180 DEGREES AROUND ITS CIRCUMFERENCE.  A MAXIMUM OF 0.008 INCHES OF PLAY IS ALLOWED IN THE RADIAL DIRECTION BETWEEN THE BALL AND THE PITCH CHANGE LINK ASSEMBLY; HOWEVER, NO LIMIT IS SPECIFIED FOR THE AXIAL DIRECTION.  THE PILOT REPORTED THAT HE COMPLETED A REQUIRED DAILY INSPECTION OF THE AIRCRAFT THE DAY BEFORE THE ACCIDENT AND OBSERVED NO PLAY                                    INEITHER TAIL ROTOR PITCH LINK, NOR DID HE SEE ANY CRACKS. HE ALSO REPORTED THAT HE PERFORMED A PREFLIGHT BEFORE TAKEOFF ON THE ACCIDENT FLIGHT AND DID NOT NOTE ANY DISCREPANCIES AT THAT TIME.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX98LA184](https://openairdocs.org/ntsb/LAX98LA184), Jun 6, 1998: Aerospatiale AS350BA (N31621), Burbank, CA, substantial damage. Probable cause: The separation of the tail rotor pitch link due to a fatigue fracture, which resulted in the separation of the tailboom.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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