MOCA stands for Minimum Obstacle Clearance Altitude, and what is a key limitation of MOCA compared with MEA?

• A. MOCA guarantees obstacle clearance and navigation signal reception within 100 NM of the VOR; MEA guarantees obstacle clearance along the route but does not specify nav reception distance.
• B. MOCA is the minimum altitude for flight and weather minima.
• C. MOCA is used only for VFR; MEA for IFR.
• D. MOCA is the same as MEA.

Answer: (A)

MOCA is an altitude that ensures obstacle clearance along the airway and also guarantees VOR signal reception within 100 nautical miles of the VOR. The important limitation is this distance: beyond 100 miles from the VOR, you cannot rely on MOCA to guarantee the navigation signal. MEA, by contrast, ensures obstacle clearance along the route and guarantees navigation signal reception along the route itself, not limited to 100 NM from a single VOR. So the key distinction is the navigation-signal guarantee: MOCA is limited to 100 NM from the VOR, while MEA covers signal reception along the entire route segment.