At what minimum flight level must aircraft maintain for an altimeter setting of 28.41?

The correct minimum flight level that aircraft must maintain for an altimeter setting of 28.41 inches of mercury is 2000 feet. This is rooted in aviation regulations that specify the minimum altitude to maintain in relation to specific altimeter settings.

When the altimeter setting is below 29.92 inches of mercury, pilots are required to fly at specific altitudes to ensure safe vertical separation from terrain and other traffic. This altitude is typically set at 2000 feet above the Minimum Enroute Altitude (MEA) for the airspace in which the aircraft is operating. Therefore, with a setting of 28.41, aircraft need to maintain at least 2000 feet to comply with safety regulations.

Choosing any level below this would increase the risk of terrain collision or infringements upon the airspace of other aircraft, as it may not provide the necessary vertical separation. Additionally, flying at an altitude above 2000 feet reduces the likelihood of issues related to changes in the altimeter setting affecting altitude measurements. Thus, maintaining 2000 feet ensures compliance with the requirements for operating under lower altimeter settings.