Which of the following types of aircraft may be maintained under an approved inspection program by the operator?

The correct choice pertains to the specific regulations surrounding approved inspection programs for aircraft. A 12-seat multi-engine turbine airplane under commuter rules typically qualifies for an approved inspection program as outlined in 14 CFR Part 135, which governs commuter and on-demand operations.

Under this regulation, operators of commuter category aircraft are authorized to employ an approved inspection program that is tailored to the operational needs and safety of the aircraft. Such programs can provide more flexibility than standard maintenance schedules, allowing operators to create a maintenance plan that ensures safety while accommodating their specific operational requirements.

In contrast, a 30-seat large airplane operating under Part 25 generally falls into the transport category and is subject to different regulatory standards. Although transport category airplanes can have approved maintenance programs, the specific inclusion of an inspection program by an operator is not as straightforward as it is for commuter category aircraft. The regulations for Part 25 aircraft often indicate more rigorous oversight and standardized inspections rather than allowing operators to develop a customized program.

Understanding these regulations and their application helps clarify why the 12-seat multi-engine turbine airplane under commuter rules is more appropriately associated with the option for maintenance under an approved inspection program while the 30-seat large airplane has more stringent requirements.