# SDR CALA2023112403465

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 22, 2023
- Submitted: November 24, 2023
- Operation: Air carrier
- Aircraft: [N77518](https://openairdocs.org/aircraft/N77518), registered now
- Make and model: Boeing 737824
- Aircraft serial: 31605
- Aircraft time: 48,022 hours, 17,074 cycles
- System (JASC): [3400 · Navigation System](https://openairdocs.org/jasc/3400)
- Part: Unknown
- Part number: UNKNOWN
- Part serial: NA
- Condition: Unknown
- Location: Unknown
- Stage of operation: CR
- How discovered: O
- Nature of condition: J, O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2023112403465

## Discrepancy

VERIFY POSITION MESSAGE SHOWS ON CDU AND POS SHIFT PAGE SHOWS LA RGE IRS DRIFT IRS-L DRIFT. PERFORMED IR FAILURE - FAULT ISOLATION REFERENCE: 34-21 TASK 803 FOR MESSAGE 34-21002 , ADIRS ENTER HEADING - FAULT ISOLATION REFERENCE: 34-21 TASK 808 FOR MAINT MESSAGE 34-21009 AND IR DATA INVALID - FAULT ISOLATION REFERENCE: 34-21 TASK 806 MAINT MESSAGE 34-21037 . NO CURRENT FAULTS FOUND . REALIGNED , AND ALL OPERATIONAL CHECKS NORMAL. PERFORMED ADIRS BITE PROCEDURE REFERENCE: 34-21 TASK 801 AND FIMS LISTED IN LOGPAGE 6363379 . ALL OPS CHECKS NORMAL . NO CURRENT FAULTS FOUND .

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