The Trim Air Loop circuit connected to Bleed Management Controller 1 (BMC) has been detected with an Open Center Conductor or short circuit between the Center Conductor and the Outer Sheath. Inhibited during Take-Off and Landing.

• Bleed Air Leak-Detection System
• Trim Air Loops
• Bleed Management Controller 1 (BMC) (A69)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW700-36-0365 - Bleed Management Controller - Data Gathering to Reduce No Fault Found (NFF) Rate
• AW700-36-0826 - Kidde Bleed Leak Detection Loops Notice of Escape

Full Throttle Blog/Forum Articles/Infoservice/Newsletter:

• Forum Article 2011-VOL 8 issue 23 - Bleed Management Controller (BMC) Top 10 No Fault Found (NFF) vs. Reliability Improvement Modification Program (RIMP) implementation
• Questionnaire for replacing the BMC. Follow instructions using this (Fill out form)

Flight Operation Notifications Manual (FONM): None

NOTES:

• Always verify you are working with the current document revision. Access the CIC website to ensure the latest document revision.
• Refer to AIPC 36-12-03 for Left outboard Wing A/ICE Leak Detection Loops.
• The sensing element is used to find a temperature that is too hot. When the eutectic salt is heated to its alarm temperature, it forms a conductive path between the center wire conductor and the outer sheath of the sensing element. This path transmits a signal that gives an alarm signal to the detection circuit.
• Let the temperature of the sensing element become stable at ambient room temperature. Write the temperature.
• To prevent damage to the sensing element connector, install test pins in the connectors when you do the continuity and insulation resistance tests.

CAUTION:

• WHEN PERFORMING THE CONDUCTANCE TEST OF THE LEAK DETECTION LOOPS, DO NOT USE A METER THAT APPLIES DC VOLTAGE. DO NOT USE INSULATION RESISTANCE “MEGGER” TESTERS OR DIELECTRIC VOLTAGE “HYPOT” TESTERS. THESE WILL DAMAGE THE SENSING ELEMENT.
• DO NOT DO TESTS OF A SENSING ELEMENT THAT IS HEATED TO WITHIN 100°F (55°C) OF ITS ALARM TEMPERATURE.

1. Disconnect A69P2 from BMC 1.
2. Measure Insulation resistance and line resistance of the detection loops as per the Leak Detection Elements troubleshooting sheet. Make sure line resistance & insulation values are within the specified limits.

   1. If the values are within specified limits, go to step 4.
   2. If values are not within the specified limits, continue with next step.

3. Replace faulty elements.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

4. Make sure the Leak Detection Elements are installed as per Bleed Air Leak Detection System-Maintenance Practices.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

5. Perform wiring checks of the remaining wires linking the Trim Air Loops circuit to BMC 1.

   1. If wiring checks are not good, repair defective wiring as required and do close out.
   2. If wiring checks are good, continue with next step.

6. Replace BMC 1.
7. Do close out.