29Basic OperationSelectable Nav Data Fields for Map Pages 2-4Option Name Abbrev. Description UnitsHorizontal Fig-ure of MeritHFOM The current 95% confidence horizon-tal accuracy value, as reported by theGPS engine.Feet (ft) or meters (m) in whole unitresolution.Minimum SafeAltitudeMSA The minimum safe altitude in theaircraft’s present vicinity. This value isdashed out if data is unknown or thedatabase is invalid.Feet (ft) or meters (m) in whole unitresolution.OutsideTemperatureOAT The current outside air temperaturevalue. This requires an FADC or COGuardian input.Degrees Celsius (ºC)True Airspeed TAS The true airspeed is only available ifan air data computer is providing it.Value is dashed out otherwise.Knots (kt), kilometers per hour (k/h),or miles per hour (m/h). 0 to 999units at 1 unit resolution.Track AngleErrorTKE The Track Angle Error (TKE) is thedifference between the aircraft’s trackand desired track. TKE is followed byan L or an R, indicating left or rightof DTK (if value is 0 or 180, then L/Rwill not be displayed). Value is dashedout if TRK or DTK is unavailable.0 to 180 degrees at one-degree resolu-tion.Track TRK The aircraft’s ground track angle. Valueis dashed out if position is invalid.0 to 359 degrees at 1-degree resolu-tion.Moving Map
