Answer: ALTITUDE

AnswerCrossword Clue
ALTITUDEGPS reading
altitudeheight above sea level
altitudethe height of a thing above a reference point, as sea level
ALTITUDESomething to gain from flying?
ALTITUDEHeight
ALTITUDEBase-to-apex measure
ALTITUDEMountaineer's problem.
ALTITUDEWhat a quadrant measures.
ALTITUDEWhat airplanes need.
ALTITUDEYour highness?
ALTITUDEGeometry calculation
ALTITUDEAthletes' concern at the '68 Summer Olympics
ALTITUDEPilot's concern
ALTITUDEFlight instrument datum
ALTITUDEElevation
ALTITUDEFactoid in a pilot's announcement
ALTITUDEHigh number?
ALTITUDECockpit reading