What is the minimum altitude for IFR flight over mountainous terrain?

The minimum altitude for IFR flight over mountainous terrain is 2000 feet above the highest obstacle in the area. This requirement is set to provide an adequate safety margin, ensuring that aircraft remain above potential obstacles, which could include peaks, towers, and other structures. The requirement is crucial since mountainous terrain can be unpredictable and challenging, especially during adverse weather conditions or restricted visibility.

By maintaining this altitude, pilots can better ensure their aircraft's safety and reduce the risk of inadvertent collisions with terrain or obstacles. The regulation reflects an understanding of the risks associated with flying in and around mountainous areas and aims to establish a safe buffer that enhances overall flight safety during instrument operations.

Other altitudes listed as options do not align with the specific FAA requirements for IFR operations in mountainous areas, which is explicitly set at 2000 feet above the highest obstacle.