# SDR QR9R20211029001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 29, 2021
- Submitted: October 29, 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: 15723979779
- Aircraft time: 2,374 hours
- System (JASC): [7700 · Engine Indicating System](https://openairdocs.org/jasc/7700)
- Part: Tachometer
- Part number: 9580119410
- Part serial: 367E1
- Condition: Faulty
- Stage of operation: CR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QR9R20211029001

## Discrepancy

#2 ENGINE OVERSPEED FAIL LIGHT DID NOT EXTINGUISH ON CAD. T/F: #1 OVSP FAIL LIGHT DID NOT EXTINGUISH ON CAD. AFTER PREVIOUS FAULT ON #2 SIDE, OVERSPEED BOXES WERE SWAPPED. FAILURE FOLLOWED THE SWAPPED BOX FROM THE #2 SIDE TO THE #1 SIDE. REPLACED #1 OVERSPEED BOX (ARRIEL SPC : 77-31-80-01-010Q) IAW AMM 80-20-00 4-1.

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