Safe & Arm Device, Electro Mechanical
Isolates for Safety, Aligns for Power


Electromechanical Safe & Arms (S&A) are commonly used on launch vehicle, missile, and manned space platforms to provide initiation of safety critical energetic systems such as FTS destruct charges and solid rocket motors. S&As are rotating mechanisms that move detonators in-line (ARM) and out-of-line (SAFE) with downstream ordnance to prevent inadvertent initiation while in the SAFE position and assure reliable initiation when in the ARM position.

Principle of Operation

Electrical detonators are rotated from the SAFE to ARM position (and from ARM to SAFE) when commanded to do so. When electrical power is supplied to the S&A torque motor, it overcomes mechanical holding force and provides rapid transition. The S&A has mechanical detents to keep the S&A in position after control power is removed. When Armed and a suitable firing current is applied, electric detonators provide reliable explosive signal to the S&A output ports.


S&As have a compact, robust aluminum body that houses the critical components of the device. The S&As have a bi-directional torque motor that rotates the body between the SAFE and ARM positions. The S&A has a visual indicator (viewing port) of the SAFE / ARM positional status. The device’s construction allows for various options for the pre-determined rotation angle required to ARM the device. Redundant mechanical detents provide locking of the internal rotor in the commanded position. A Safing Key can be inserted into the device to provide manual Safing. The safing key cannot be removed when arm power is applied to provide additional safety. The Safing Key Port can be factory rotated to be conveniently positioned on any side of the S&A.


S&As are typically used for safe initiation of critical system events such as flight termination and solid rocket motors used on tactical missiles, launch vehicles and manned space platforms. EBAD has single channel and dual channel configurations.

Key Features

    • Internal electric detonators
    • Robust torque motor and detents
    • Single or dual channel configurations
    • Qualified with EBAD FCDCA Explosive Transfer Lines (ETL)