In aviation, a minimum crossing altitude, or MCA, is the lowest altitude at which a navigational fix can be crossed when entering or continuing along an airway that will allow an aircraft to clear all obstacles while carrying out a normal climb to the required minimum en route IFR altitude (MEA) of the airway in question beyond the fix.
minimum crossing altitudeとは意味:《航空》最低通過高度{さいてい つうか こうど}◆【略】MCA minimum crossing altitude meaning:[Defence] The lowest altitude at certain radio fixes at which an aircraft must cross when proceeding in the direction of a higher minimum en route instrument flight rules altitude.