08/09/21
Message Overview:
Fault Description:
Possible Causes:
- R Pylon Duct leak
- R Pylon Bleed Air Loop routing
- R Pylon Loop 2B (MT44)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Operational Test of the Bleed-Air Leak-Detection and Warning System | AMM 36-21-00-710-801 |
| Initiation Test of the Bleed-Air Leak-Detection Loops | AMM 36-21-00-740-801 |
| Resistance Check of the Bleed-Air Leak-Detection Loops | AMM 36-21-00-760-801 |
| Bleed-Air Leak-Detection System - Component Location | AMM 36-21-00-992-801 |
| Removal of the Right Pylon-Loop Element | AMM 36-21-07-000-801 |
| Installation of the Right Pylon-Loop Element | AMM 36-21-07-400-801 |
| Removal of the Right Pylon Anti-Ice Leak-Detection Element | AMM 36-21-07-000-802 |
| Installation of the Right Pylon Anti-Ice Leak-Detection Element | AMM 36-21-07-400-802 |
| Fenwal Safety Systems | CMM 26-14-47 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Going into the system diagnostics to the IASC #2 channel B to display the IASC Channel B menu. The IASC LRU test page will provide pages to perform a leak detection system test and check past event locations.
- Locate the short circuit or leak using the Leak Event location function.
- Check for short circuit at the corresponding connector.
- Check the loop routing for a fouling condition on a hot surface (loop touching duct).
NOTE: Before replacing a loop always look at the loop for routing, ensure loop is not too close to the plumbing or the bleed hole on a valve. Review AMM 36-21-00-992-801 for component location. See individual loops for specific routing information. - Use a Tegam meter to check capacitance and inductance between the inner and outer conductor of the corresponding loop. Perform the impedance check per the Leak Detection How To.
- If R Pylon Bleed loop is shorted replace loop.
