Under what condition is an alternate airport not required for a supplemental or commercial air carrier turbojet-powered airplane on an IFR flight outside the contiguous United States?

The correct answer states that an alternate airport is not required for a supplemental or commercial air carrier turbojet-powered airplane on an IFR flight outside the contiguous United States if enough fuel is onboard to fly to the destination and then continue flying for at least 2 more hours at normal cruising fuel consumption.

This regulation is established because it ensures that the aircraft has a significant margin of safety in terms of fuel, allowing the pilot to reach the destination and maintain extra fuel reserves for unexpected circumstances, such as weather changes or holding patterns. The requirement to hold for two additional hours reflects the operational needs of an aircraft, providing the necessary flexibility when alternatives may not be available.

Other options do not offer a comparable level of safety or regulation adherence. For example, requiring only enough fuel for 30 minutes of holding above the destination may not accommodate all potential contingencies. Similarly, options discussing cruising speeds do not provide assurances about fuel availability beyond the destination, which could lead to a situation where an aircraft runs low on fuel without an adequate plan for unexpected delays or diversions. The gasoline specifications and operational guidelines clearly highlight the importance of being equipped with fuel that accounts for a variety of potential situations, emphasizing the critical nature of option B as the safest choice.