Definition
Preplanned instrument flight rule (IFR) procedures published by the FAA that provide obstacle clearance from the takeoff runway to the en route structure. They come in two forms: Obstacle Departure Procedures (ODPs), which exist solely to provide obstacle clearance, and Standard Instrument Departures (SIDs), which provide obstacle clearance and also serve air traffic control needs by establishing standardized routes out of busy airports.
Plain English
These are published instructions for safely getting an aircraft from the runway up into the en route airway system when flying on instruments. They tell the pilot exactly what headings, altitudes, and routes to fly so the aircraft stays clear of terrain and obstacles after takeoff.
Context Anchor
Seen during instrument flight planning, in an instrument clearance, on departure charts, and in the takeoff briefing before an instrument flight.
Derivation
"Instrument" refers to flight conducted by reference to cockpit instruments rather than visual cues. "Departure procedure" simply means a defined set of steps for leaving the airport. The phrase together signals that this is the IFR version of a departure plan, designed for use when outside visual references may not be available.
Why Pilots Care
They guarantee terrain and obstacle clearance in low visibility or at night, reducing the risk of controlled flight into terrain during the critical climb phase.
Grounding Statement
After takeoff in poor visibility, the procedure gives the pilot a known safe way to climb away from the airport instead of guessing a path.
Intuition Check
Do not assume this means any departure made while looking at the instruments. Here, it means a specific published or assigned procedure with required paths, climbs, and instructions.
Example Sentence 1
Before takeoff from a mountainous airport in low visibility, the pilot briefed the published instrument departure procedure to ensure the climb route would clear the surrounding terrain.
Example Sentence 2
After departure the controller cleared the flight direct via the instrument departure procedure.