Which CFR part governs maintenance, preventive maintenance, and alterations to aircraft?

Which CFR part governs maintenance, preventive maintenance, and alterations to aircraft?

• A. 14 CFR Part 91
• B. 14 CFR Part 43
• C. 14 CFR Part 39
• D. 14 CFR Part 21

Answer: (B)

Maintenance, preventive maintenance, and alterations are governed by the rule that sets who may perform the work, what data must be followed, and how the work is documented. This regulation ensures tasks are done to approved standards using current maintenance data, with the proper inspections and a signed-off record that keeps the aircraft’s airworthiness current. That makes it the best choice because it directly covers the processes, responsibilities, and documentation involved in keeping aircraft maintained. The other parts address operating rules, mandatory directives, and how aircraft and parts are certified or approved, not the day-to-day maintenance framework.

Maintenance, preventive maintenance, and alterations are governed by the rule that sets who may perform the work, what data must be followed, and how the work is documented. This regulation ensures tasks are done to approved standards using current maintenance data, with the proper inspections and a signed-off record that keeps the aircraft’s airworthiness current. That makes it the best choice because it directly covers the processes, responsibilities, and documentation involved in keeping aircraft maintained. The other parts address operating rules, mandatory directives, and how aircraft and parts are certified or approved, not the day-to-day maintenance framework.