# SDR 2019FA0000406

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 12, 2019
- Submitted: December 12, 2019
- Operation: General aviation
- Aircraft: N861RB
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 172S11180
- Aircraft time: 3,723 hours
- Engine: Lyc IO360L2A
- Engine time: 3,941 hours
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Intake Valve
- Part number: 17A23938
- Condition: Leaking
- Location: Engine
- Part time: 607 hours
- Stage of operation: CL
- How discovered: O
- Nature of condition: R
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2019FA0000406

## Discrepancy

DURING CRUISE/CLIMB PERIOD OF FLIGHT, FLIGHT CREW FELT A LOSS OF RPM AND ENGINE ROUGHNESS/VIBRATION.  FLIGHT CREW TERMINATED FLIGHT AND LANDED AIRCRAFT.  MAINTENANCE PERSONEL TROUBLESHOT AND INSPECTED IGNITION/SPARK PLUGS, FUEL SYSTEM FOR DEFECTS. NO DEFECTS NOTED.  PERFORMED DIFFERENTIAL PRESSURE CYLINDER LEAK CHECK AND DISCOVERED CYLINDER #4 WAS LEAKING BY THE INTAKE VALVE.

---
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.