What is the minimum altitude for IFR flight, except when necessary for takeoff or landing or otherwise authorized?

The minimum altitude for IFR (Instrument Flight Rules) flight is indeed designated as 2,000 feet over mountainous terrain and 1,000 feet over other terrain. This regulation is in place to ensure that aircraft maintain a safe distance from the ground, particularly in areas where the terrain features can pose hazards to flight safety.

In mountainous regions, the higher minimum altitude provides additional safety margins due to the potential for sudden altitude changes and the rugged nature of the terrain, where obstacles may be more prevalent. In areas with less elevation and obstacles, the 1,000-foot requirement allows for sufficient clearance while still maintaining safety and efficiency in flight operations.

This two-tier system for minimum altitudes reflects the varying risks associated with different types of terrain and emphasizes the importance of maintaining safe operating standards under IFR conditions. The regulation specific to IFR flight ensures pilots are aware of their surroundings and adhere to established safety protocols, ultimately enhancing flight safety and operational integrity.