Instrument Rating Checkride Practice Test

Which altitude is not associated with Minimum Sector Altitude (MSA)?

1. A minimum clearance of 1,000' above all obstacles

2. An altitude that enhances fuel efficiency

3. 1000’ above defined obstacles within a 25NM sector

4. It applies under emergency conditions only

The correct answer is: An altitude that enhances fuel efficiency

The correct answer is based on the understanding of Minimum Sector Altitude (MSA) and its specific function in aviation operations. MSA is established as a minimum altitude that ensures a safe vertical clearance over the highest obstacle in a designated sector. In this context, the altitude is designed to provide a minimum clearance of at least 1,000 feet above all obstacles, which enhances safety during instrument approaches and emergencies. In contrast, MSA is not concerned with optimizing fuel efficiency. Instead, it is strictly focused on obstacle clearance and safety. This altitude is not adjusted for fuel economy but rather defined by the physical terrain and obstacles within a certain radius. Therefore, while fuel efficiency is an important consideration in flight planning, it does not apply to MSA. The other options relate directly to the defined purposes and criteria for MSA, which include ensuring safe clearance above terrain and obstacles within a specified distance.