Answer: altitude

AnswerCrossword Clue
ALTITUDE

Your highness?

ALTITUDE

Cockpit reading

ALTITUDE

High number?

ALTITUDE
Factoid in a pilot's announcement
ALTITUDE
Elevation
ALTITUDEFlight instrument datum
ALTITUDEPilot's concern
ALTITUDEAthletes' concern at the '68 Summer Olympics
ALTITUDEGeometry calculation
ALTITUDEGPS reading
ALTITUDEWhat airplanes need.
ALTITUDEWhat a quadrant measures.
ALTITUDEMountaineer's problem.
ALTITUDEBase-to-apex measure
ALTITUDEHeight
ALTITUDESomething to gain from flying?