# SDR 20000427SH014

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 25, 2000
- Submitted: April 27, 2000
- Operation: General aviation
- Aircraft: [N718EH](https://openairdocs.org/aircraft/N718EH), registered now
- Make and model: Cessna 172R
- Registry model: [Cessna 172R](https://openairdocs.org/model/cessna-172r) (OpenAirDocs)
- Aircraft serial: 17280061
- System (JASC): [2400 · Electrical Power System](https://openairdocs.org/jasc/2400)
- Part: Switch
- Part number: S337711
- Condition: Failed
- Location: Avionics Master
- Stage of operation: NR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/20000427SH014

## Discrepancy

ONE-HALF OF SPLIT AVIONICS MASTER BUS SWITCH FAILED.  DEFECTIVE HALF OF SWITCH WILL NOT TURN OFF LEAVING SOME AVIONICS SYSTEMS POWER CONTROLLED BY A/C MASTER SWITCH.  SWITCH FAILED UNDER NORMAL OPERATING PARAMETERS.  POSSIBLE CAUSE OF FAILURE IS DUE TO POOR SWITCH DESIGN AND SUBMITTER STATED NEEDS TO BE RE-DESIGNED.  (X)

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