06/07/19
Message Overview:
Fault Message:
FLAP LEFT ABRAKE/ SFCU/ WRG
Fault Code:
2750025STD
Associated CAS:
| Reporting LRU: | Slat/Flap Control Unit (SFCU) |
| System Description: | 27-52-00 |
| Schematic Diagram: | 27-50-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 27-50-03 [ Global Express ] [ G5000 ] [ Global XRS ] 27-50-04 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
One of the conditions that follow occurs:
- Over-current condition in the Brake Drive
- Outputs to the Flap Asymmetry Brake disagree with inputs from the brake
- During IBIT brake drive test the left resolver moved >2.5 degrees for more than 0.2 second
Possible Causes:
- Left Flap Asymmetry Brake (A128)
- Slat/Flap Control Unit (SFCU) 1 (A124)
- Slat/Flap Control Unit (SFCU) 2 (A95)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Vendor Service Bulletin:
- Hamilton supplier released VSB FAS02AB-27-1 for upgrading the asymmetry brake to -3
If FLAP FAIL message posted, Check to see if CAIMS reports a LATCHED FAULT on both SFCUs; also the FLAP LEFT ABRAKE/ SFCU/ WRG is posted on the one SFCU that caused the Latched Fault. Use the CAIMS, LRU Test Menu, "Clear Latched Fault" reset procedure to clear the Latched Faults before starting troubleshooting below. This Clear Latched Faults procedure may need to be repeated in between steps of troubleshooting if the Fail message returns.
- Flap fails=flap asymmetry brake dual channels failure or brake seizure
- Flap half speed=only one channel available from the asymmetry brake
- Flap fault=asymmetry brake coil resistance out of range
Ensure cover decal is properly installed on the top drain hole to avoid any dust accumulation, which can affect the Asymmetry Brake functionality (Refer to SIL 470 Rev B from Hamilton Sundstrand).
Quick Links:
| Removal of the Slat/Flap Control Unit (SFCU) | AMM 27-51-05-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Slat/Flap Control Unit (SFCU) | AMM 27-51-05-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Removal of the Flap Asymmetry Brakes | AMM 27-52-53-000-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Installation of the Flap Asymmetry Brakes | AMM 27-52-53-400-801 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 [ Global Express ] [ G5000 ] [ Global XRS ] |
Troubleshooting Recommendations:
- On the EMS CDU, select CTRL function and SLAT/FLAP RESET.
NOTE: Wait at least one minute after SFCU reset to allow self-test to run.- If system checks are good, do close out.
- If fault remains, continue with next step.
- Swap SFCU 1 with SFCU 2.
- If system checks are good, replace SFCU 1 and do close out.
- If fault remains, continue with next step.
NOTE: SFCU 1 is the left side (channel 1) controller. SFCU 2 is the right side (channel 2) controller.
- Perform wiring checks between the applicable SFCU rack and left Flap asymmetry brake.
- If wiring checks are not good, repair defective wiring as required and do close out.
- If wiring checks are good, continue with next step.
NOTE: Wing asymmetry brake coil value.From To Expected Result Result A124CP1-33 A124CP1-21 2.63 to 3.21 ohms A95CP1-33 A95CP1-21 2.63 to 3.21 ohms
- Replace the Flap left wing asymmetry brake.
- Do close out.