# SDR F3LA200400066

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 6, 2004
- Submitted: June 8, 2004
- Operation: Air carrier
- Aircraft: [N312FL](https://openairdocs.org/aircraft/N312FL), registered now
- Make and model: Boeing 737-3L9
- Registry model: [Boeing 737-3L9](https://openairdocs.org/model/boeing-737-3l9) (OpenAirDocs)
- Aircraft serial: 24569
- Aircraft time: 37,563 hours, 28,869 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Loop
- Condition: Faulty
- Location: Nr 2 Engine
- Stage of operation: CL
- How discovered: O
- Nature of condition: N
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/F3LA200400066

## Discrepancy

AIR RETURN, NR 2 ENG OVERHEAT CAUTION LIGHT ILLUM TWICE.  DECLARED EMERGENCY, LANDED W/O INCIDENT.  ON DESCENT, MASTER CAUTION SYS ILLUM 4 TIMES, NO SIX PACK INDICATION.  MX TESTED CAUTION SYS THRU SIMULATION OF CONDITIONS CAUSING ILLUMIN ANNUNCIATORS, ALL SYS OPERATED NORM.  COULD NOT DUPLICATE.  REPLACED NR 2 ENG PRSOV, LEAK CHECKED OK.  PERFORMED LEAK CHECK NR 2 ENG AIR DUCTS, NO LEAKS FOUND.  RAN NR 2 ENG AT T/O POWER APPROX 2 MIN & ENG OVERHEAT LIGHT ILLUM.  SWITCHED OVER TO A-LOOP, FAULT REMAINED.  SWITCHED TO B-LOOP, FAULT WENT AWAY.  PROBLEM COULD ONLY BE DUPLICATED WITH ENGINE HOT.  PLACARD NR 2 ENG A-LOOP, COMPLIED WITH SPECIAL PROCEDURES.  PERFORMED OVERWEIGHT LANDING INSPECTION, NO DEFECTS FOUND.

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