# SDR QR9R20210827003

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 27, 2021
- Submitted: August 27, 2021
- Operation: General aviation
- Filed by: [M1 Support Services, repair station QR9R369D](https://openairdocs.org/faa-repair-station/QR9R369D/m1-support-services.md) (OpenAirDocs)
- Make and model: Bolkms BK117C2
- Aircraft serial: 0872077
- Aircraft time: 1,639 hours
- System (JASC): [6320 · Main Rotor Gearbox](https://openairdocs.org/jasc/6320)
- Part: Transmission
- Part number: B632K1001051
- Part serial: KA0837
- Condition: Corroded
- Location: Main Rotor
- Part time: 1,639 hours
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QR9R20210827003

## Discrepancy

A MAINTENANCE INSPECTION OF THE M/R TRANSMISSION ASSY REVEALED CORROSION DUE TO WATER INTRUSION AND POOR VENTILATION. TRANSMISSION ASSY REPLACED; LIMITED TEST FLIGHT COMPLETED IAW 05-60-00, 6-1.

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