What altitude is designated for a fix when reception of signals from a radio facility is inadequate at the designated MEA?

The Minimum Reception Altitude (MRA) is the designated altitude that ensures adequate signal reception from a radio facility when the Minimum Enroute Altitude (MEA) may not provide sufficient coverage. An MRA is particularly important for navigating in areas where higher terrain or other obstructions may interfere with the transmission of radio signals.

By operating at the MRA, pilots can ensure that they remain within a safe altitude range that allows them to receive necessary navigational signals reliably. This altitude is typically lower than the MEA but is specifically established for the purpose of maintaining radio reception. It provides pilots with a way to safely navigate and stay in contact with air traffic control or navigational aids when faced with inadequate signal strength at the MEA.

In contrast, the other options serve different purposes or do not apply to this specific context. For instance, the Minimum Enroute Altitude is the lowest altitude at which adequate navigational signal reception is guaranteed, while Recommended Altitude and Block Altitude pertain to other operational guidelines and restrictions.