Advisory Wire/Service Bulletin:

• AW700-27-0373 - SFCU -17: “SLAT-FLAP HALFSPD” EICAS Nuisance Message

Forum Articles/Infoservice/Newsletter: None

• Performing a SLAT FLAP RESET on the EMS CDU may clear this fault
  NOTE: Wait at least one minute after SFCU reset to allow self-test to run.
• Moving the SFCL to another detent may also clear this fault
• Performing the CAIMS latched fault clear may also clear this fault

Access CAIMS - active faults to see if one or both SFCUs are reporting the problem.

Fault reported by only one SFCU:

1. Swap SFCUs.

   1. If system checks are good, replace defective SFCU and do close out.
   2. If fault remains, continue with next step.
      NOTE: If necessary perform the clear latched fault after swapping the SFCU.

2. Swap Flap PDU motors.

   1. If system checks are good, replace defective flap PDU motor and do close out.
   2. If fault remains, continue with next step.

3. Perform wiring checks from the SFCU racks as follow:

   Fault reported by the SFCU 1 (SLAT/FLAP CONTROL UNIT 1 STN 493 LHS):

   From	To	Resistance Range	Result
   A124DP1-4	A124DP1-3	0.4050 to 0.2550 ohms
   A124DP1-3	A124DP1-8	0.4050 to 0.2550 ohms
   A124DP1-8	A124DP1-4	0.4050 to 0.2550 ohms
   A124AP1-89	A124AP1-102	9 to 11 ohms
   A124AP1-104	A124AP1-103	45.9 to 56.1 ohms
   A124AP1-91	A124AP1-103	45.9 to 56.1 ohms
   A124AP1-90	A124AP1-103	45.9 to 56.1 ohms

   Fault reported by the SFCU 2 (SLAT/FLAP CONTROL UNIT 2 STN 493 RHS):

   From	To	Resistance Range	Result
   A95DP1-4	A95DP1-3	0.4050 to 0.2550 ohms
   A95DP1-3	A95DP1-8	0.4050 to 0.2550 ohms
   A95DP1-8	A95DP1-4	0.4050 to 0.2550 ohms
   A95AP1-89	A95AP1-102	9 to 11 ohms
   A95AP1-104	A95AP1-103	45.9 to 56.1 ohms
   A95AP1-91	A95AP1-103	45.9 to 56.1 ohms
   A95AP1-90	A95AP1-103	45.9 to 56.1 ohms

   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.

4. Perform torque/backlash check of the flap system.

   1. If check is normal, go to step 6.
   2. If there is friction or drag in the system, continue with next step.

5. Repair mechanical defects.

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

6. Replace flap PDU.
7. Do close out.

Fault reported by both SFCUs:

1. Energize AC and DC power of one SFCU to clear the latched fault.

   1. If latched fault is clear, go to step 3.
   2. If latched fault remains, continue with next step.

2. Energize the other SFCU.

   1. If latched fault remains, go to step 5.
   2. If no latched fault remains, continue with next step.

3. Operate at half speed by one SFCU only, and confirm if the flaps can be operated at half speed by the same SFCU in the other position.

   1. If any SFCU cannot operate at half speed, go to step 5.
   2. If one SFCU can operate at half speed, swap SFCU.

      1. If flaps can be operated at half speed by the same SFCU, do close out.
      2. If flaps cannot be operated at half speed by the same SFCU, continue with next step.

4. Swap flap PDU motor with any slat PDU motor to the SFCU that latched fault cannot be cleared.
   NOTE: SFCU 1=Flap PDU motor 1 (left), SFCU 2=Flap PDU motor 2 (right).

   1. If system checks are good, replace flap PDU motor and do close out.
   2. If fault remains, continue with next step.

5. Perform torque/backlash check of the flap system.

   1. If check is normal, go to step 7.
   2. If there is friction or drag in the system, continue with next step.

6. Repair mechanical defects.

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

7. Replace flap PDU.
8. Do close out.