§ 417.409 System hazard controls. ( a ) *General.* A launch operator must establish and maintain hazard controls for each system that presents a public hazard as identified by the ground safety analysis and satisfy the requirements of this section. A launch operator must: ( 1 ) Ensure a system be at least single fault tolerant to creating a public hazard unless other hazard control criteria are specified for the system by the requirements of this part. A system capable of creating a catastrophic public hazard must be at least dual fault tolerant. Dual fault tolerant system hazard controls include: Switches, valves, or similar components that prevent an unwanted transfer or release of energy or hazardous materials;
( 2 ) Ensure each hazard control used to provide fault tolerance is independent from other hazard controls so that no single action or event can remove more than one inhibit. A launch operator must prevent inadvertent activation of hazard control devices such as switches and valves;
( 3 ) Provide at least two fully redundant safety devices if a safety device must function in order to control a public hazard. A single action or event must not be capable of disabling both safety devices; and
( 4 ) Ensure computing systems and software used to control a public hazard satisfy the requirements of § 417.123.
( b ) *Structures and material handling equipment.* A launch operator must ensure safety factors applied in the design of a structure or material handling equipment account for static and dynamic loads, environmental stresses, expected wear, and duty cycles. A launch operator must: ( 1 ) Inspect structures and material handling equipment to verify workmanship, proper operations, and maintenance;
( 2 ) Prepare plans to ensure proper operations and maintenance of structures and material handling equipment;
( 3 ) Assess structures and material handling equipment for potential single point failure;
( 4 ) Eliminate single point failures from structures and material handling equipment or subject the structures and material handling equipment to specific inspection and testing to ensure proper operation. Single point failure welds must undergo both surface and volumetric non-destructive inspection to verify that no rejectable discontinuities exist;
( 5 ) Establish other non-destructive inspection techniques if a volumetric inspection cannot be performed. A launch operator, in such a case, must demonstrate through the licensing process that the inspection processes used accurately verify the absence of rejectable discontinuities; and
( 6 ) Ensure qualified and certified personnel, as defined in § 417.105, conduct the inspections.
( c ) *Pressure vessels and pressurized systems.* A launch operator must apply the following hazard controls to a pressurized flight or ground pressure vessel, component, or systems: ( 1 ) Qualified and certified personnel, as defined in § 417.105, must test each pressure vessel, component, or system upon installation and before being placed into service, and periodically inspect to ensure that no rejectable discontinuities exists;
( 2 ) Safety factors applied in the design of a pressure vessel, component, or system must account for static and dynamic loads, environmental stresses, and expected wear;
( 3 ) Pressurized system flow-paths, except for pressure relief and emergency venting, must be single fault tolerant to causing pressure ruptures and material releases during launch processing; and
( 4 ) Provide pressure relief and emergency venting capability to protect against pressure ruptures. Pressure relief devices must provide the flow rate necessary to prevent a rupture in the event a pressure vessel is exposed to fire.
( d ) *Electrical and mechanical systems.* A launch operator must apply the following hazard controls to electrical or mechanical systems that can release electrical or mechanical energy during launch processing: ( 1 ) A launch operator must ensure electrical and mechanical systems, including systems that generate ionizing or non-ionizing radiation, are single fault tolerant to providing or releasing electrical or mechanical energy;
( 2 ) In areas where flammable material exists, a launch operator must ensure electrical systems and equipment are hermetically sealed, explosion proof, intrinsically safe, purged, or otherwise designed so as not to provide an ignition source. A launch operator must assess each electrical system as a possible source of thermal energy and ensure that the electrical system can not act as an ignition source; and
( 3 ) A launch operator must prevent unintentionally conducted or radiated energy due to possible bent pins in a connector, a mismated connector, shorted wires, or unshielded wires within electrical power and signal circuits that interface with hazardous subsystems.
( e ) *Propulsion systems.* A propulsion system must be dual fault tolerant to inadvertently becoming propulsive. Propulsion systems must be single fault tolerant to inadvertent mixing of fuel and oxidizer. Each material in a propulsion system must be compatible with other materials that may contact the propulsion system during launch processing including materials used to assemble and clean the system. A launch operator must use engineering controls, including procedures, to prevent connecting incompatible systems. A launch operator must comply with § 417.417 for hazard controls applicable to propellants and explosives.
( f ) *Ordnance systems.* An ordnance system must be at least single fault tolerant to prevent a hazard caused by inadvertent actuation of the ordnance system. A launch operator must comply with § 417.417 for hazard controls applicable to ordnance. In addition, an ordnance system must satisfy the following requirements; ( 1 ) A launch operator must ensure ordnance electrical connections are disconnected until final preparations for flight;
( 2 ) An ordnance system must provide for safing and arming of the ordnance. An electrically initiated ordnance system must include ordnance initiation devices and arming devices, also referred to as safe and arm devices, that provide a removable and replaceable mechanical barrier or other positive means of interrupting power to each ordnance firing circuit to prevent inadvertent initiation of ordnance. A mechanical safe and arm device must have a safing pin that locks the mechanical barrier in a safe position. A mechanical actuated ordnance device must also have a safing pin that prevents mechanical movement within the device. A launch operator must comply with section D417.13 of this part for specific safing and arming requirements for a flight termination system;
( 3 ) Protect ordnance systems from stray energy through grounding, bonding, and shielding; and
( 4 ) Current limit any monitoring or test circuitry that interfaces with an ordnance system to protect against inadvertent initiation of ordnance. Equipment used to measure bridgewire resistance on electro-explosive devices must be special purpose ordnance system instrumentation with features that limit current.