# SDR 2009FA0000586

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 26, 2009
- Submitted: June 26, 2009
- Operation: General aviation
- Aircraft: [N60FT](https://openairdocs.org/aircraft/N60FT), registered now
- Make and model: Cessna 550
- Registry model: [Cessna 550](https://openairdocs.org/model/cessna-550) (OpenAirDocs)
- Aircraft serial: 5500470
- Aircraft time: 6,681 hours, 6,153 cycles
- System (JASC): [3452 · ATC Transponder System](https://openairdocs.org/jasc/3452)
- Part: Transponder
- Part number: 0110049010
- Condition: Malfunctioned
- Location: Instrument Panel
- Part time: 254 hours, 156 cycles
- 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/2009FA0000586

## Discrepancy

BOTH TRANSPONDERS LOSE ALTITUDE INPUT FOR 1 MINUTE WHEN SWITCHING BETWEEN ADC 1 AND ADC 2. MFG TECH SUPPORT STATED THEY ENGINEERED A 1 MINUTE DELAY IN ALTITUDE REPORTING AFTER RECEIVING A VALID ALTITUDE AND INCORPORATED THE DELAY IN A SOFTWARE REVISION BEFORE THE 2.09 REVISION. THE MFG TECH DID NOT KNOW THE EXACT SOFTWARE REVISION IT WAS INCORPORATED ON.

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