A valve for controlling an emergency brake system on an aircraft. The valve has separate poppets for controlling the flow of fluid from a supply line to the brake cylinders and from the brake cylinders to a tank return line. The poppets act on each other. A dampening orifice restricts fluid flow around one of the poppets thereby limiting the rate at which that poppet opens and closes. An actuator applies an externally generated control force to the poppets to activate and de-active the emergency brake system.