What is the requirement for a person taking off an aircraft under IFR from an airport with takeoff weather minimums but below landing minimums?

The requirement for a person taking off an aircraft under Instrument Flight Rules (IFR) from an airport where takeoff weather minimums are met but landing minimums are not is to have a plan that includes flying for an adequate amount of time to ensure safety. The correct answer specifies "1 hour at normal cruise speed in still air of the departure airport."

This means that the pilot must be prepared to remain airborne for this duration in order to safely navigate to an alternate airport or to find improved conditions. By indicating “normal cruise speed”, it emphasizes maintaining a standard operational speed that is typical for that aircraft, which is essential for fuel planning and ensuring a smooth transition to a safe environment for landing. The mention of "still air" implies consideration of wind factors, reinforcing the need to calculate accurate flight time and distance needed under calm conditions.

The other options do not specifically capture the critical components necessary for ensuring the pilot can manage the flight under the circumstances outlined, such as addressing changing conditions or ensuring a drone approach to alternate landing locations. Therefore, the emphasis on actual cruising speed in still air of the departure airport makes this choice the most appropriate and aligned with IFR standards for maintaining safety and operational effectiveness.