Under Section 12(4), in discharging its functions under Section 12, the Authority shall have due regard to the development of air transport service and to:

Section 12(4) establishes the Authority's guiding regulatory philosophy while performing its Section 12 functions: due regard must be given to the development of air transport service AND to the efficiency, economy, and safety of that service - a tripartite operational standard (efficiency + economy + safety) rather than a profitability-driven, politically-driven, seniority-driven, or manufacturer-preference-driven standard. This mirrors the 'business principles' mandate under Section 11 but adds a public-interest-oriented qualifier specific to the discharge of Section 12 functions, ensuring that even while acting commercially, the Authority must not compromise on safety or economic efficiency of the broader air transport ecosystem it serves.