Message Name:

FLAP OVERSPEED

Message Code:

B3-276369

Associated CAS:

FLAPS FAIL
(Caution)

Flap Control Unit (FCU) detected a over-speed condition in the LH or RH driveline. Check LH and RH wing Flap driveline for disconnect.

• Mechanical Failure in the Transmission System
• Left Flap Position Sensor (MPE77)
• Right Flap Position Sensor (MPE78)
• Flap Control Unit (FCU) (A124)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW300-27-0058 - Flap Control Unit - CAS Messages Reset procedure

Forum Articles/Infoservice/Newsletter: None

In the MDC system parameters, an FPU PRESS XDCR SIGNAL showing 3,740 psi indicates the FCU have detected a malfunction in the system and do not send the excitation signal to the FPU pressure transducer.

1. Reset the following circuit breakers.

   FLAP R IND	CB2-B12
   FLAP L IND	CB1-B13
   FLAP CTRL	CB1-B14

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

2. Reset the FCU by pressing the FCU reset button on the MAINTENANCE TEST control panel. If unable to reset, engage the Alternate Flaps button with the left hydraulic system pressurized, and attempt another reset using the Flap Reset switch on the left galley.

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

3. Verify current faults or fault message history shows the FLAP OVERSPEED fault.

   1. FCU label 355 bit 11 set to 1 show LH Flap panel over-speed.
   2. FCU label 355 bit 12 set to 1 show RH Flap panel over-speed.

4. Verify integrity of driveline by pulling and pushing on the flap panel and by attempting to rotate the driveline by hand.

   1. If system checks are good, do close out.
   2. If problem remain continue to next step.

5. Perform a visual inspection of the flex shafts, AGB, hard shafts and actuators.

   1. Check for loose parts, stripped gears, etc. Replace defective parts per AMM.
   2. If problem remains, continue to next step.

6. Access and disconnect the left and right position sensors. Visually inspect the connector and pins for signs of water ingress or any type of damage.

   1. If no damage or defect is found, continue with next step.
   2. If damage or defects are found, rectify as required.

7. Perform a resistance check of both position sensors on both channels as follows:
   LH Position Sensor Channel A
   

   From	To	Expected Result	Result
   MPE77P1-1	MPE77P1-2	110Ω
   MPE77P1-3	MPE77P1-4	75Ω
   MPE77P1-5	MPE77P1-6	75Ω
   MPE77P1-1	Ground	Open
   MPE77P1-2	Ground	Open
   MPE77P1-3	Ground	Open
   MPE77P1-4	Ground	Open
   MPE77P1-5	Ground	Open
   MPE77P1-6	Ground	Open

   LH Position Sensor Channel B

   From	To	Expected Result	Result
   MPE77P2-1	MPE77P2-2	110Ω
   MPE77P2-3	MPE77P2-4	75Ω
   MPE77P2-5	MPE77P2-6	75Ω
   MPE77P2-1	Ground	Open
   MPE77P2-2	Ground	Open
   MPE77P2-3	Ground	Open
   MPE77P2-4	Ground	Open
   MPE77P2-5	Ground	Open
   MPE77P2-6	Ground	Open

   RH Position Sensor Channel A

   From	To	Expected Result	Result
   MPE78P1-1	MPE78P1-2	110Ω
   MPE78P1-3	MPE78P1-4	75Ω
   MPE78P1-5	MPE78P1-6	75Ω
   MPE78P1-1	Ground	Open
   MPE78P1-2	Ground	Open
   MPE78P1-3	Ground	Open
   MPE78P1-4	Ground	Open
   MPE78P1-5	Ground	Open
   MPE78P1-6	Ground	Open

   RH Position Sensor Channel B

   From	To	Expected Result	Result
   MPE78P2-1	MPE78P2-2	110Ω
   MPE78P2-3	MPE78P2-4	75Ω
   MPE78P2-5	MPE78P2-6	75Ω
   MPE78P2-1	Ground	Open
   MPE78P2-2	Ground	Open
   MPE78P2-3	Ground	Open
   MPE78P2-4	Ground	Open
   MPE78P2-5	Ground	Open
   MPE78P2-6	Ground	Open

   1. If all results are good as per tables above, continue with next step.
   2. If values are found out of range, replace defective position sensor and do close out.

8. Perform a continuity check between the position sensors and the Flap Control Unit (FCU) as follows:
   LH position sensor:
   

   From	To	Result
   MPE77P1-1	A124AP1-8F
   MPE77P1-2	A124AP1-8E
   MPE77P1-3	A124AP1-10F
   MPE77P1-4	A124AP1-10E
   MPE77P1-5	A124AP1-9F
   MPE77P1-6	A124AP1-9E
   MPE77P2-1	A124BP1-14K
   MPE77P2-2	A124BP1-15K
   MPE77P2-3	A124BP1-14H
   MPE77P2-4	A124BP1-15H
   MPE77P2-5	A124BP1-14J
   MPE77P2-6	A124BP1-15J

   RH position sensor:

   From	To	Result
   MPE78P1-1	A124BP1-9F
   MPE78P1-2	A124BP1-9E
   MPE78P1-3	A124BP1-11F
   MPE78P1-4	A124BP1-11E
   MPE78P1-5	A124BP1-10F
   MPE78P1-6	A124BP1-10E
   MPE78P2-1	A124AP1-14K
   MPE78P2-2	A124AP1-15K
   MPE78P2-3	A124AP1-14H
   MPE78P2-4	A124AP1-15H
   MPE78P2-5	A124AP1-14J
   MPE78P2-6	A124AP1-15J

   NOTE: Make sure there is no continuity to ground on each wire.

   1. If there is continuity, continue with next step.
   2. If there is no continuity, repair defective wiring as required and do close out.

9. Replace FCU.

   1. If system checks are good, do close out.
   2. If problem remain continue to next step.

10. Do close out.