Which of the following is not a typical scope of line maintenance?

• A. Inspections
• B. Parts replacement
• C. Repairs
• D. Major on-aircraft overhaul

Answer: (D)

Line maintenance is about keeping the aircraft airworthy between flights right on the ramp or at the base. The work is typically quick and focused, so the aircraft can return to service with minimal downtime. Inspections, parts replacement, and repairs all fit that scope because they are tasks that can be done on the line, with limited teardown and time.

Major on-aircraft overhaul, by contrast, involves extensive disassembly, rebuilds or replacements of major components, and comprehensive testing. It requires specialized facilities, equipment, and longer downtime, and it’s planned as part of a heavy maintenance program in a dedicated shop or overhaul facility. That’s why it’s not considered a typical line maintenance activity.