# SDR CA100525020

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 22, 2010
- Submitted: January 4, 2011
- Operation: General aviation
- Make and model: Dhav DHC2MKI
- Aircraft time: 12,673 hours
- Engine: Pwa R985AN14B
- Propeller: Hamstd 2D30
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Cylinder Head
- Part number: 399353CA1
- Condition: Cracked
- Location: Engine
- 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/CA100525020

## Discrepancy

ACFT WAS BROUGHT IN FOR INSP WITH NO DEFECTS NOTED BY PILOT.  INVESTIGATION OF A LOW CYLINDER COMPRESSION DURING THE DIFFERENTIAL COMPRESSSION INSP, REVEALED A CRACK THAT STARTED AT THE FWD SPARK PLUG HOLE AND ENDED AT THE EXHAUST VALVE SEAT.  THE CYLINDER ASSY WAS PREVIOUSLY OVERHAULED, O/H FACILITY HAS TRADITIONALLY PUT OUT A GOOD O/H CYLINDER, THIS IS THE FIRST CRACK THAT THIS AIRLINES HAS HAD IN MANY YEARS OF OPERATING THESE CYLINDER ASSEMBLIES.

---
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.