# SDR ABXA2023050882

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 2, 2023
- Submitted: May 8, 2023
- Operation: Air carrier
- Aircraft: [N651GT](https://openairdocs.org/aircraft/N651GT), registered now
- Make and model: Boeing 767231
- Aircraft serial: 22570
- Aircraft time: 89,588 hours, 27,109 cycles
- System (JASC): [7712 · Engine BMEP/Torque Indicating](https://openairdocs.org/jasc/7712)
- Part: Tach Generator
- Part number: 8TJ141AAA3
- Part serial: D1003
- Condition: Intermittent
- Location: Left Engine
- Stage of operation: TX
- How discovered: V
- Nature of condition: J
- Precautionary procedure: D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ABXA2023050882

## Discrepancy

N1'S FLUCTUATING AT IDLE BOTH ENGINES 23.3-26.5 ACCOMPANIED BY INTERMITTENT VIBRATION IN COCKPIT THAT DOES NOT APPEAR ON VIBRATION GAUGES. ALL OTHER EICAS GAUGES WITHIN LIMITS. AIRCRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE REMOVED AND REPLACED LH N1 TACH. TRANSMITTER IAW B767 AMM 77-12-01. ACCOMPLISHED N2 INDICATION OPS CHECK ON BOTH ENGINES IAW B767 AMM 77-12-00 OPS CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.