Check on 12α Panel

Engage the heating switch of the velocity vector sensor and indicator“GSS.HEAT”on 7α panel extinguishes;engage the heating switch of the pitot tube and indicator“PITOT”on 7α panel extinguishes(ground heating shall not exceed 2 minutes);engage the tail servo cutoff solenoid valve and indicator“HYD.LEVEL”on 7α panel extinguishes;engage cyclic trim switch and check if the trim release buttons(DBM)on cyclic pitch levers click clearly;engage horn warning switch and indicator“HORN”on the 7α panel extinguishes.