Definition
A preplanned instrument flight rule (IFR) procedure published for pilots to use when departing an airport, providing a safe, obstacle-free route from the runway to the en route structure. Departure procedures come in two forms: Obstacle Departure Procedures (ODPs), which provide obstruction clearance, and Standard Instrument Departures (SIDs), which also assist air traffic control with managing traffic flow.
Plain English
A published set of instructions telling an IFR pilot exactly how to fly out of an airport safely after takeoff, keeping clear of terrain and obstacles and getting onto their planned route.
Context Anchor
You see DPs in instrument flying, before takeoff, in an IFR clearance, or on departure charts used to plan the first part of the flight after leaving the runway.
Why Pilots Care
Following a DP ensures the aircraft maintains required obstacle clearance during the critical climb phase after takeoff in instrument conditions.
Intuition Check
A departure procedure is not just any takeoff plan or personal habit. In this context, it means a specific published or assigned instrument departure path or instruction set that must be followed as given.
Example Sentence 1
Before takeoff in low visibility, the pilot reviewed the departure procedure to confirm the required climb gradient and initial heading.
Example Sentence 2
ATC cleared the aircraft to follow the published DP that led directly to the en route airway.