The electrical arc and short circuit faults caused by metal redundancy in three-phase AC circuit of aircraft are simulated in laboratory. In three-phase alternating current circuit, electric arc and short circuit will cause damage of wiring and equipment. To analyze the protection function of traditional TCB for electric arc and short circuit. Traditional TCB cannot protect electric arc. It is very important to study the hazards and protection of aviation electric arc and short circuit. In this paper, several new methods of electric arc detection and protection are studied.