# SDR CA160128005

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 21, 2016
- Submitted: April 22, 2016
- Operation: General aviation
- Make and model: Bell 429
- Registry model: [Bell 429](https://openairdocs.org/model/bell-helicopter-textron-canada-429) (OpenAirDocs)
- Engine: Pwc PW207D
- System (JASC): [6330 · Main Rotor Transmission Mount](https://openairdocs.org/jasc/6330)
- Part: Spring
- Part number: 429310201105
- Condition: Failed
- Location: Pitch Restraint
- Part time: 12 hours
- Stage of operation: HO
- How discovered: O
- Nature of condition: E
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA160128005

## Discrepancy

(CAN) PILOT REPORTED A VIBRATION (ABNORMAL) AND "SHIFTING" FELT IN HOVER AND DURING FLIGHT. A PRECAUTIONARY LANDING WAS CARRIED OUT. PILOTS OBSERVED THAT THE TRANSMISSION WAS RESTING ON "PIN BACK-UP MOUNTS". AN AME WAS DISPATCHED TO INSPECT THE ACFT, A FLIGHT TEST WAS CARRIED OUT TO CONFIRM THE MAIN ROTOR TRANSMISSION RESTRAINT CONDITION AND THE ACFT WAS ALLOWED TO RETURN TO BASE WITH A SPEED RESTRICTION OF 80 KNOTS VNE.  DEBONDING BETWEEN INNER MEMBER AND OUTER MEMBER OF ASSY. THE PITCH RESTRAINT SPRING ASSY DID HAVE AN ASB 429-13-10 ON 29 APRIL 2013 ON A LIMITED QTY OF UNITS THAT WERE MANUFACTURED WITH INADEQUATE ADHESIVE MIX RATIO BETWEEN THE TUBE AND THE HOUSING. THIS CONDITION MAY CAUSE A BOND LINE SEPARATION. ACFT WAS NOT PART OF THE HELICOPTER AFFECTED.

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