Definition
The phase of instrument flight that begins at takeoff and continues until the aircraft is established on its en route course, during which the pilot follows a published or ATC-assigned route, altitude, and climb profile to transition safely from the airport environment to the en route structure.
Plain English
The flying you do right after takeoff to get safely away from the airport and onto your planned route. It covers the climb-out, the turns, and the headings you fly until you join the main part of your trip.
Context Anchor
Seen when planning or flying the first part of a flight after takeoff, especially when following an instrument departure procedure.
Derivation
Departure comes from an older word meaning “to part” or “go away.” Navigation comes from Latin words tied to directing a ship. Together, the phrase means directing the aircraft as it goes away from the airport.
Why Pilots Care
It keeps the aircraft clear of terrain and obstacles during the most critical low-altitude phase of flight.
Intuition Check
Do not read departure navigation as simply “pointing away from the airport.” In aviation, it means following a planned or assigned path after takeoff.
Example Sentence 1
Before takeoff, the pilot briefed the departure navigation, including the assigned heading, climb altitude, and the fix where they would join their en route course.
Example Sentence 2
Good departure navigation ensures the aircraft stays on course while climbing through the clouds.