M303 Set 1 Introductory Terms

Front 1

above ground level (AGL)

Back 1

(n.) height (ofan

aircraft)above the actual surface of the earth (i.e., the absolute altitude). Cloudheights in airport weather observations and forecasts are

also usually reportedin AGL. Compare with MEAN SEA LEVEL (MSL).

Front 2

azimuth

Back 2

(n.) angular measurement in degrees, clockwise from 0 to 360. Azimuth may betrue, magnetic, or relative. True azimuth is measured from true north; magneticazimuth is measured from magnetic north; and relative azimuth is measured fromthe heading of the aircraft from which the reading is taken.

Front 3

bearing

Back 3

(n.) 1. an angularmeasurement of

directionbetween a known point and the aircraft in flight, usually measured clockwisefrom TRUE

NORTH(true bearing), MAGNETIC NORTH (magnetic bearing), or some other referencepoint, through

360 degrees. 2. a surface designed to slide orrotate easily over another surface; used to reduce friction between movingparts (ball bearing)

Front 4

cardinal direction

Back 4

(n.) the four main headings of the compass: north, east, south, and west.

Front 5

compass

Back 5

(n.) an instrumentused to determine

direction (fromMAGNETIC NORTH).

Front 6

course

Back 6

(n.) the intended route or direction to be followed, measured with respect toa geographic reference. Magnetic course is measured from MAGNETIC NORTH. Truecourse is measured from TRUE NORTH.

Front 7

dead reckoning (DR)

Back 7

(n.) navigationof an aircraft based on last known position, airspeed,

course, heading, winddirection, wind speed, ground speed, and elapsed time.

Front 8

deviation

Back 8

(n.) compass errorcaused by magnetic disturbances from electrical and metal components in theaircraft. The correction for this erroris displayed on a compass correction card placed near the

aircraft’s magneticcompass.

Front 9

geography

Back 9

(n.)

1. ascience that deals with the description, distribution, and interaction of thediverse physical, biological, and cultural features of the earth's surface; 2the geographicfeatures of an area

Front 10

heading

Back 10

(n.) thehorizontal direction in which

theLONGITUDINAL AXIS of an aircraft is pointing; expressed as the angular distancefrom north, (clockwise from 360 degrees). Magnetic heading is measured fromMAGNETIC NORTH. True heading

is measured from TRUENORTH. Heading is equal to COURSE

Front 11

knot (kt)

Back 11

(n.) a unit of speed equal to one NM per hour. 1 knot = 1.15 mph = 1.85 km/h.All speeds filed on flight plans and for air traffic control purposes are inknots. By definition, the term knot assumes “per hour.” Therefore, speed should never be stated as “knotsper hour.”

Front 12

low-level navigation

Back 12

(n.) a navigationsortie in which the pilot flies low to the ground (500 to 2,000 feet) at arelatively high speed. Sometimes referred to simply as a low-level.Low-level missions are designed to introduce students to navigation methods andtactics used in major weapon systems. By

primarily using DEADRECKONING procedures backed up with PILOTAGE techniques, the pilot attempts tofly over a designated target at a certain point in time. Low-levels in theUnited States are flown within designated MILITARY TRAINING ROUTES.

Front 13

mean sea level (MSL)

Back 13

(n.) theaverage height of the surface of the sea for all stages of tide; used as a referencefor elevations throughout the

United States. MSLshould not be confused with above ground level (AGL), which indicates the height(of an aircraft) above the actual surface of the earth at any given point.

Front 14

nautical mile (NM)

Back 14

(n.) the basic unit of air navigation. One NM equals 1.15 statute miles or1.85 kilometers. One NM also equals 6076 feet, the same as one minute oflatitude. Each DEGREE of latitude, therefore, equals 60 nautical miles.

Front 15

pilotage

Back 15

(n.) another term for VISUAL NAVIGATION.

Front 16

statute mile (SM)

Back 16

(n.) a measureof length

equal to 1.6kilometers or 5,280 feet. A statute mile is equal to .868 nautical miles.

Front 17

track

Back 17

1. (n.) the actualpath of the aircraft above the surface of the earth. Note: The term course refersto the path that is planned; track refers to the path that is actuallytaken. 2. (v.) to observe or plot the path of a moving object(e.g., an aircraft) using radar. 3. (v.) to follow a desired track.In air combat contexts, tracking refers to

successfully pursuingan enemy and maintaining a stabilized gun solution.

Front 18

visual navigation

Back 18

(n.) navigationof an aircraft

from one visiblelandmark to another using only a chart. It is necessary during this process to maintaindirect visual contact with the earth’s surface. Visual navigation is alsoreferred to as pilotage.