Slat/flat surface movements during initiated built in test (IBIT)

Effectivity: Global 7500 aircraft

ATA 27

By design, the Global 7500 slat and flap system computer, Salt and Flap Electronic Control Unit (SFECU) will perform the Initiated Built -in Test (IBIT) every 48 hours calendar (the system is linked to the aircraft GPS for clock input). If power is applied to the aircraft, the IBIT will be completed every 48 hours; if power was not applied, the IBIT will be initiated at next aircraft power up. The IBIT can also be initiated manually in the aircraft Onboard Maintenance System (OMS).

The IBIT will cause a momentary movement of the torque tubes and slightly change the retracted position of the flap/slat control surfaces. If the IBIT is performed four (4) to five (5) times, either initiated through the OMS maintenance page or at the 48 hours interval (with aircraft power applied), a CAS fault message will be posted. Cycling the slats/flap with the Slat Flap Control Lever (SFCL) will bring the panels back to the proper retracted position, no adjustments are required.

It is important to consider the IBIT during slat and flap rigging. If the electrical rigging task that requires to keep the AC breakers pulled is not followed correctly, this could result in an unwanted movement of the control surface prior to setting the electrical rigging zero values. This requires a mechanical readjustment of the slats or flaps.

Bombardier and the SFECU supplier have corrected this issue and will be implemented in an upcoming SFECU software update.