A method comprising: receiving data (α11) indicative of deflection of a tower supporting a wind turbine having a rotating rotor, the rotor including multiple blades (20, 23, 26), each of the blades including a plurality of air deflector units (31, 34, 37) and multiple sensors (30, 33, 36), each of the air deflector units including a deflector element extendable into and retractable from air flow over a portion of the blade, the air deflector units of the blades having a current collective deployment configuration; receiving from each of the blades, independently and in parallel, sensor data comprising sensor values (S1 - S1(j); S2 - S2(j); S3 - S3(j)) corresponding to each of the multiple sensors of that blade; characterized by generating a first data value (Q COL) based at least in part on the received data indicative of deflection of the tower; converting, for each of the blades, the first data value into data (Δh CB1 - Δh CB1 (k), Δh CB2 - Δh CB2 (k), Δh CB3 - Δh CB3 (k)) representing a collective deployment configuration; generating, independently and in parallel for each of the blades, a per-blade second data value (Q PB1, Q PB2, Q PB3,) corresponding to a per-blade deployment configuration for that blade; converting (1199b, 1199d, 1199f), in parallel for each of the blades, the second data value generated for that blade (Q PB1, Q PB2, Q PB3,) into data (Δh PB1 - Δh PB1 (k), Δh PB2 - Δh PB2 (k), Δh PB3 - Δh PB3 (k)) representing a per-blade deployment configuration for that blade; determining (1199c, 1199e, 1199g), in parallel for each of the blades, a combined deployment configuration (Δh COMB1 - Δh COMB1 (k), Δh COMB2 - Δh COMB2 (k), Δh COMB3 - Δh COMB3 (k)) based on a combination of the per-blade deployment configuration for that and the collective deployment configuration; generating (1199h, 1199i, 1199j), in parallel for each of the blades and based on the respective combined deployment configurations for each of the blades, actuator commands to at least one of the air deflector units of each of the blades to implement an updated collective deployment configuration of the air deflector units of the blades; and transmitting the actuator commands. receiving data (α11) indicative of deflection of a tower supporting a wind turbine having a rotating rotor, the rotor including multiple blades (20, 23, 26), each of the blades including a plurality of air deflector units (31, 34, 37) and multiple sensors (30, 33, 36), each of the air deflector units including a deflector element extendable into and retractable from air flow over a portion of the blade, the air deflector units of the blades having a current collective deployment configuration; receiving from each of the blades, independently and in parallel, sensor data comprising sensor values (S1 - S1(j); S2 - S2(j); S3 - S3(j)) corresponding to each of the multiple sensors of that blade; characterized by generating a first data value (Q COL) based at least in part on the received data indicative of deflection of the tower; converting, for each of the blades, the first data value into data (Δh CB1 - Δh CB1 (k), Δh CB2 - Δh CB2 (k), Δh CB3 - Δh CB3 (k)) representing a collective deployment configuration; generating, independently and in parallel for each of the blades, a per-blade second data value (Q PB1, Q PB2, Q PB3,) corresponding to a per-blade deployment configuration for that blade; converting (1199b, 1199d, 1199f), in parallel for each of the blades, the second data value generated for that blade (Q PB1, Q PB2, Q PB3,) into data (Δh PB1 - Δh PB1 (k), Δh PB2 - Δh PB2 (k), Δh PB3 - Δh PB3 (k)) representing a per-blade deployment configuration for that blade; determining (1199c, 1199e, 1199g), in parallel for each of the blades, a combined deployment configuration (Δh COMB1 - Δh COMB1 (k), Δh COMB2 - Δh COMB2 (k), Δh COMB3 - Δh COMB3 (k)) based on a combination of the per-blade deployment configuration for that and the collective deployment configuration; generating (1199h, 1199i, 1199j), in parallel for each of the blades and based on the respective combined deployment configurations for each of the blades, actuator commands to at least one of the air deflector units of each of the blades to implement an updated collective deployment configuration of the air deflector units of the blades; and transmitting the actuator commands.