# SDR 2010FA0000977

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 23, 2010
- Submitted: September 9, 2010
- Operation: General aviation
- Aircraft: [N556ER](https://openairdocs.org/aircraft/N556ER), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 172S10561
- Engine: Lyc IO360L2A
- Propeller: Mcauly 1A170E
- System (JASC): [2710 · Aileron Control System](https://openairdocs.org/jasc/2710)
- Part: Control Cable
- Part number: 0510105364
- Condition: Frayed
- Location: Aileron
- Part time: 2,095 hours
- 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/2010FA0000977

## Discrepancy

CABIN OVERHEAD CTR PANEL REMOVED FOR PROGRESSIVE INSP.  DURING FLAP & AILERON CABLE INSPECTION, FLAT SPOTS WERE NOTICED ON 2 AILERON CONTROL CABLES.  ROLLED CABLES FOR BETTER VIEW OF CONTACT POINT WITH PULLEYS, WAS ABLE TO CATCH FRAYED WIRES WITH A RAG & COULD SEE A SUBSTANTIAL GROOVE IN THE CARRY-THRU CABLE.  CABLE TENSIONS WERE WITH PROPER SPECS & AREA CLEAN & FREE OF DIRT/DEBRIS.  PLASTIC PULLEYS INSPECTED, THEY WERE CLEAN & FREE TO ROLL.  PROBLEM SEEMS TO HAPPENING DURING NORMAL FLT TRAINING SCHOOL USE & HAS BEEN NOTICED TO BE HAPPENING WITH ALL OF OUR ACFT WITH SIMILAR ACFT TT.  CAUSE OF PROBLEM CAN BE ATTRIBUTED TO PULLEYS, THEY ARE MADE FROM A HARD WHITE PLASTIC MATERIAL.  BRAIDED STAINLESS STEEL CABLES ARE RUBBING AGAINST PULLELYS INSTEAD OF ROLLING ON THEM.  THIS CAUSES THE CABLES TO FLAT SPOT AT FIRST & THEN CUT A GROOVE DEEP INTO THE CABLE.  THERE IS ALSO NO NOTICEABLE CABLE DEFLECTION WHERE CABLES CONTACT PULLEYS, SEEMS PULLEY DIAMETER IS TOO SMALL.  SUGGEST REPLACING PLASTIC PULLEYS WITH A STANDARD PHENOLIC PULLEYS THAT ARE USED IN ALL OTHER AREAS OF THE ACFT.

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