What altitude should a pilot maintain while flying before reaching a fix?

Maintaining the current Minimum Enroute Altitude (MEA) until reaching a fix is essential for ensuring safe navigation while flying under Instrument Flight Rules (IFR). The MEA is established to provide obstacle clearance and adequate signal transmission from navigation aids within that route segment. By adhering to the MEA, pilots ensure they are flying at a safe altitude that accounts for any terrain and obstacles along their intended route.

Additionally, the MEA provides a level of redundancy by ensuring that if any changes occur, such as unexpected weather conditions, the pilot will remain at a safe altitude. This is particularly crucial when navigating complex airspace or mountainous regions where terrain can pose a significant risk.

The other choices, while they may seem relevant, each have limitations: the altitude indicated on the sectional chart can vary and may not provide the necessary clearance; maintaining only the cruising altitude disregards the specific requirements of the airway; and depending solely on ATC can be misleading if the clearance is not specific to the situation leading to the fix. Therefore, adhering to the MEA provides the safest and most reliable altitude to maintain until reaching the fix.