Under 14 CFR Part 23, what type of circuit protective device is required for starter motors?

Under 14 CFR Part 23, what type of circuit protective device is required for starter motors?

• A. Circuit protective devices are not required.
• B. Fusible link that is non-accessible to the crew.
• C. Trip-free device which cannot be overridden.
• D. Circuit protective devices are required for all starter circuits

Answer: (A)

When thinking about protection in Part 23 airplanes, not every circuit needs its own dedicated protective device. The starter motor is part of the main electrical protection scheme rather than a separate, standalone circuit. The heavy current involved in starting is brief and is routed through the same protection that guards the power source and main distribution—such as the battery’s protection or a main circuitbreaker/fusible link in the supply line. Since the starter is controlled by a switch that only energizes the circuit momentarily, the regulatory framework doesn’t require a separate circuit protective device specifically for the starter circuit. In other words, the existing protection in the power source and main wiring is considered sufficient, so no additional starter-specific protective device is mandated.

When thinking about protection in Part 23 airplanes, not every circuit needs its own dedicated protective device. The starter motor is part of the main electrical protection scheme rather than a separate, standalone circuit. The heavy current involved in starting is brief and is routed through the same protection that guards the power source and main distribution—such as the battery’s protection or a main circuitbreaker/fusible link in the supply line. Since the starter is controlled by a switch that only energizes the circuit momentarily, the regulatory framework doesn’t require a separate circuit protective device specifically for the starter circuit. In other words, the existing protection in the power source and main wiring is considered sufficient, so no additional starter-specific protective device is mandated.