# SDR 2003FA0001128

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 4, 2003
- Submitted: November 4, 2003
- Operation: General aviation
- Aircraft: [N37HY](https://openairdocs.org/aircraft/N37HY), registered now
- Make and model: Aviat A-1B
- Registry model: [Aviat A-1B](https://openairdocs.org/model/aviat-a-1b) (OpenAirDocs)
- Aircraft serial: 2037
- Aircraft time: 962 hours
- Engine: Lyc O360*
- System (JASC): [2140 · Heating System](https://openairdocs.org/jasc/2140)
- Part: Duct
- Condition: Chafed
- Location: Heater
- Stage of operation: NR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2003FA0001128

## Discrepancy

GROOVES WORN IN ROCKER BOX OIL RETURN TUBE.  AUXILLIARY HEAT AIR DUCT AT LOWER SIDE OF NR 1 CYL WAS RUBBING ON OIL RETURN TUBE.  GROOVES APPEARED TO BE 30 PERCENT TO 50 PERCENT THROUGH TUBE.  AIRPLANE WAS 2.2 HOURS TIME IN SERVICE AFTER ANNUAL / 100 HOUR INSPECTION.  HEAT DUCT HAS TO BE CRUSHED TO FIT THIS INSTALLATION.  THERE IS INADEQUATE ISOLATION BETWEEN DUCT AND ENGINE CYLINDER LUBRICATING OIL RETURN TUBE.

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