A320 Systems

Question 1

AUTOTHRUST LOGIC

Answer 1

-The A/THR can only be active, when the thrust levers are between IDLE and the CLB detent

-When the thrust levers are beyond the CLB detent, thrust is controlled manually to the thrust lever
Angle, and the A/THR is armed (A/THR appears in blue on the FMA). This means that the A/THR
is ready to be re-activated, when the flight crew sets the thrust levers back to the CLB detent (or
below)

-In case of engine failure, the thrust levers will be in MCT detent for remainder of the flight

-When the aircraft’s angle-of-attack goes beyond the ALPHA FLOOR threshold, this means that the
aircraft has decelerated significantly (below ALPHA PROT speed): A/THR activates automatically
and orders TOGA thrust, regardless of the thrust lever position.

-When the aircraft accelerates again, the angle-of-attack drops below the ALPHA FLOOR
threshold. TOGA thrust is maintained or locked. This enables the flight crew to reduce thrust, as
necessary. TOGA LK appears on the FMA to indicate that TOGA thrust is locked. The desired
thrust can only be recovered by setting A/THR to off, with the instinctive disconnect pushbutton.

-SUMMARY:

Use of A/THR is recommended during the entire flight.
It may be used in most failures cases, including:
‐ Engine failure, even during autoland
‐ Abnormal configurations.