# SDR J7SA2026100500528

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 21, 2026
- Submitted: October 5, 2026
- Operation: Air carrier
- Aircraft: [N507FX](https://openairdocs.org/aircraft/N507FX), registered now
- Make and model: Bombdr BD1001A10
- Aircraft serial: 20947
- Aircraft time: 4,459 hours, 2,558 cycles
- Engine: Hnywl AS90721A
- System (JASC): [7320 · Fuel Controlling System](https://openairdocs.org/jasc/7320)
- Part: Hmu
- Part number: 442661
- Part serial: FHC3444
- Condition: Unserviceable
- Location: Lt Engine
- Stage of operation: CR
- How discovered: O
- Nature of condition: P
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/J7SA2026100500528

## Discrepancy

DIVERSION DUE TO THE LEFT ENGINE SURGING IN CRUISE WITH NO ASSOCIATED CAS MESSAGE. AIRCRAFT LANDED WITHOUT INCIDENT AT PHNL. REPLACED THE SUSPECTED FAULTY HYDROMECHANICAL UNIT IAW CH350 AMM 73-20-01. OPERATIONAL AND LEAK CHECKS GOOD.

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