The lowest published altitude which ensures obstacle clearance and navigational signal coverage is known as what?

The term that describes the lowest published altitude ensuring both obstacle clearance and navigational signal coverage is referred to as the Minimum Enroute Altitude (MEA). MEA is specifically designed to provide a safe vertical margin over obstacles, ensuring pilots can navigate safely between waypoints throughout their flight. It guarantees that any navigational aids being used will provide adequate coverage, meaning pilots can rely on them effectively while maintaining an appropriate level of safety with respect to terrain and obstacles below.

In a broader context, other related altitudes serve different purposes: Minimum Reception Altitude (MRA) pertains to the minimum altitude needed to receive signals from navigational aids, while Minimum Obstruction Clearance Altitude (MOCA) guarantees only obstacle clearance but does not ensure navigational signal coverage. Minimum Vectoring Altitude (MVA), on the other hand, applies primarily to air traffic control and refers to the lowest altitude at which aircraft can be safely vectored. Thus, the MEA stands out as the fundamental altitude ensuring both safety from obstacles and reliable navigation throughout the enroute phase of flight.