Alternate Law Landing A330
Alternate law transitioning to Direct at gear down is an A320 not A330
Alternate law pitch control is similar to normal law. Alternate law has maneuver protection, automatic pitch trim, and ground and landing modes identical to normal law. Therefore, at 100 ft RA pitch control enters landing mode, which is close to direct law - but not exactly.
Flare mode affects only pitch and provides a direct stick-to-elevator relationship. Automatic pitch trim is disabled, but manual pitch trim is available if needed. Therefore the airplane exhibits its natural aerodynamic positive speed stability (that is, it tends to pitch down if slowed below the trimmed airspeed).
The Flare mode is blended in from Flight mode over a period of two seconds when descending below 100 feet radio altitude.
At 50 feet, a slight pitch down elevator order is applied. The purpose is to generate a more natural feel in the flare where the pilot has to move the sidestick aft to achieve a progressive flare and allow the nose to derotate after touchdown.
In contrast, if the flight-mode pitch law were to remain in effect, the sidestick would have to be neutralized once the flare attitude was reached and then after touchdown moved forward to lower the nose before the tail became aerodynamically ineffective.
Airbus has described Flare mode as “a smoother Direct law” as it has some damping provided by load factor and pitch rate feedbacks. High angle of attack protection and bank angle protection are both provided in the flare mode, though neither component is available in the actual Direct law. Pitch attitude, load factor, and high speed protection, however, are not provided.
In cases where both radio altimeters are inoperative, the normal trigger point for the Flare mode to engage cannot be determined, so Flare mode engages when both the autopilot is off and the landing gear is down. In that event, alpha floor (an autothrust function) also remains available, though it is normally disabled at 100 feet RA.
Upon touchdown, Ground mode blends in over a two second period for pitch, and the roll mode is blended in within two seconds of being on the ground and the pitch attitude decreasing below 2.5°.