# SDR QR9R20210831001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 31, 2021
- Submitted: August 31, 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: 07720199147
- Aircraft time: 2,981 hours
- System (JASC): [2300 · Communications System](https://openairdocs.org/jasc/2300)
- Part: Control Unit
- Part number: ACU61002120
- Part serial: 01486
- Condition: Failed Insp
- Location: Audio
- Stage of operation: IN
- How discovered: C
- Nature of condition: L
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QR9R20210831001

## Discrepancy

CO-PILOT ACU NAV1 COMM PUSH BUTTON WOULD NOT STAY DOWN. ACU REPLACED IAW 145MMS-016.

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