MODF must be greater than 6000 lbs when destination temperature exceeds 38°C.

• A. MODF is always 6000 lbs
• B. MODF is unrelated to temperature
• C. MODF must be greater than 6000 lbs when destination temperature exceeds 38°C
• D. MODF decreases with higher temperature

Answer: (C)

Hot conditions reduce air density, which hurts engine and aerodynamic performance and increases fuel burn for a given leg. Because of that, the flight planning rules require extra on-board fuel when the destination temperature is high. Specifically, if the destination temperature exceeds 38°C, the MODF must be greater than 6000 lbs to ensure adequate fuel for the leg and required reserves. This reflects the need for more fuel in hot conditions to maintain safety margins and mission capability. The other ideas—that MODF is fixed at 6000 lbs, is unrelated to temperature, or decreases as temperature rises—don’t match how performance and fuel planning respond to heat.