What is the minimum obstruction clearance altitude (MOCA)?

The minimum obstruction clearance altitude (MOCA) is defined as the lowest published altitude that meets the obstacle clearance requirements for the given route or segment of the flight. This altitude ensures that there is adequate vertical separation from any terrain or obstacles in the area, providing a safety margin for aircraft flying under Instrument Flight Rules (IFR).

The significance of MOCA lies in its role during navigation and in ensuring safe flight over mountainous or uneven terrain. When a pilot adheres to MOCA, it guarantees that even in the event of equipment failure or navigation issues, the aircraft will remain safely above obstacles along the specified route. Furthermore, MOCA also provides reliable navigation signals, as it is correlated with VOR (VHF Omnidirectional Range) coverage.

In contrast, the other options do not accurately describe MOCA. The lowest altitude for any flight does not specifically relate to obstacle clearance or safety. MOCA is particularly applicable to IFR flights, not to VFR (Visual Flight Rules) conditions, which operate under different criteria. Similarly, the term does not apply to standard operating altitudes for VOR flights, as VOR altitudes vary based on navigational requirements and airspace classifications. Therefore, recognizing that MOCA specifically addresses obstacle clearance helps clarify its