Important Facts and Definitions Not Found in the Legend On Low Altitude

INSTRUMENT FLIGHT RULES WORKBOOK

CHAPTER TWO

LOCALIZER (LOC): A VHF Directional Radio Beacon which provides azimuth

(directional guidance) for use in a nonprecision type approach. It is also used in conjunction

with an ILS providing azimuth information. (T-34 can utilize localizers through the VOR radio.

Check the legend for the appropriate symbol.)

MARKER BEACON: A 75-MHz beacon used to designate specific fixes in instrument

approaches. Fan and bone refer to the shapes of the signal patterns. Normally associated with

ILS approaches. Check the legend for the appropriate symbol.

MINIMUM ENROUTE ALTITUDES (MEAs): The MEA between navigation aids

along VOR airways is an altitude which will meet obstruction clearance requirements, and also

assure acceptable navigational signal reception.

MINIMUM OBSTRUCTION CLEARANCE ALTITUDE (MOCA): The specified

altitude between radio fixes on VOR airways, which meets obstruction clearance requirements

and which assures acceptable navigational signal reception within 22 NM of a VOR or

VORTAC.

MINIMUM RECEPTION ALTITUDE (MRA): The lowest altitude at which an

intersection can be determined.

MINIMUM CROSSING ALTITUDES (MCAs): The lowest altitude at certain fixes at

which an aircraft must cross when proceeding in the direction of a higher minimum enroute IFR

altitude (MEA).

STOP: DO NOT PROCEED FURTHER IN THIS TEXT UNTIL YOU HAVE READ AND

STUDIED THE CHART LEGEND IN ITS ENTIRETY.

IFR SUPPLEMENT, FLIGHT INFORMATION HANDBOOK, ENROUTE LOW

ALTITUDE CHARTS, GENERAL PLANNING, AND AREA PLANNING 2-23