10/03/19
Message Overview:
Fault Message:
L CH B AIR DATA COMPUTER T20 RNG MA
Fault Code:
7327517LBR
Associated CAS:
| Reporting LRU: | Left Engine Electronic Controller (EEC) |
| System Description: | 73-20-00 |
| Schematic Diagram: | 76-10-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 71-50-01 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
This message shows when the T20 signal of Total Air Temperature (TAT) sent by the Micro Air-Data Computers (MADCs) is not within operational parameters. The signal is sent to channel B of the Engine Electronic Controller (EEC) by the Micro Air-Data Computer (MADC) 1 or MADC 2. These circuits are continuously monitored by the Full-Authority Digital Engine-Controller (FADEC).
Possible Causes:
- Micro Air-Data Computer (MADC) 1 (A27)
- Micro Air-Data Computer (MADC) 2 (A28)
- P20/T20 Probe
- Left Engine Electronic Controller (EEC)
Troubleshooting Tips:
Advisory Wire/Service Bulletin:
- AW700-45-0065 - CAIMS Nuisance Fault Messages
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Micro Air-Data Computers | AMM 34-11-09-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Micro Air-Data Computers | AMM 34-11-09-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Engine Safety Precautions | AMM 71-00-00-910-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Opening of the Cowls | AMM 71-10-00-010-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Closing of the Cowls | AMM 71-10-00-410-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Visual Check of the Engine Controlling System | AMM 73-20-00-210-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Deactivation of the Thrust Reverser (for Maintenance) | AMM 78-30-00-040-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Activation of the Thrust Reverser (for Maintenance) | AMM 78-30-00-440-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Engine Electronic Controller (EEC) | EMM 73-21-01-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Engine Electronic Controller (EEC) | EMM 73-21-01-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- Check if the fault message shows only on ground, review AW700-45-0065 - CAIMS Nuisance Fault Messages.
- Check if the fault message happens during flight, use the Flight Test Data Sheet table to record all 3 TAT readings at various altitudes. Once all the data is recorded, compare temperature readings between all three.
- If one of the TAT probes is generally warmer than the other two, especially at higher altitudes, replace affected probe and do close out.
- If all reading values are the same on all three TAT probes throughout the flight, continue with next step.
- Swap Left EEC with Right EEC and monitor for failure at the next flight. Is the fault still present?
- If NO, replace Left EEC and do close out.
- If YES, continue with next step.
- Swap MADC 2 with MADC 3 and monitor for failure at the next flight. Is the fault still present?
- If NO, replace MADC 2 and do close out.
- If YES, continue with next step.
- Replace MADC 1.
- Do close out.