The roll mode can operate with Alternate Law.

The roll mode can operate with Alternate Law.

• A. True; it remains in Alternate Law.
• B. True; it operates in Direct Flight mode.
• C. False; it goes to Direct Law.
• D. It cannot operate at all.

Answer: (C)

In Airbus fly-by-wire, the flight control laws determine how the surfaces respond and what protections are active. Roll handling in Normal Law benefits from consulting protections and bank-angle logic, but when the system degrades to Alternate Law, many protections are lost and the control logic is reduced. The roll mode relies on those protections and the associated control law; with Alternate Law available, that specific roll-mode behavior isn’t maintained. If faults worsen or the degraded mode isn’t able to provide the necessary logic, the system kicks down to Direct Law, where pilot inputs map directly to surface movements with no envelope protections. So, the roll mode cannot operate while in Alternate Law; instead, the system goes to Direct Law.

In Airbus fly-by-wire, the flight control laws determine how the surfaces respond and what protections are active. Roll handling in Normal Law benefits from consulting protections and bank-angle logic, but when the system degrades to Alternate Law, many protections are lost and the control logic is reduced. The roll mode relies on those protections and the associated control law; with Alternate Law available, that specific roll-mode behavior isn’t maintained. If faults worsen or the degraded mode isn’t able to provide the necessary logic, the system kicks down to Direct Law, where pilot inputs map directly to surface movements with no envelope protections. So, the roll mode cannot operate while in Alternate Law; instead, the system goes to Direct Law.