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Obstacle departure procedure (ODP) is a type of departure procedure that provides obstruction clearance via the least onerous route from an airport to an appropriate en-route structure. Pilots can fly ODPs without prior clearance unless assigned a standard instrument departure or radar vectored by air traffic controllers. Unlike Standard Instrument Departures, ODPs are generally developed for smaller airports.

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ODPs may be designed using either conventional or area navigation (RNAV) criteria. ODPS can be either graphical or textual; graphical ODPs always note "(OBSTACLE)" in the title.

Assessment

When an airport is being analyzed for designing an instrument approach procedure, an obstacle departure procedure assessment is conducted first. Surveyors establish pass the departure end of the runway obstacle clearance surface (OCS), which is an imaginary surface that rises at a 40:1 ratio under standard conditions, or 152ft per nautical miles. The OCS can rise more steeply if terrain or other obstacles are present. Pass the departure end of the runway at 35ft above ground, if an aircraft can climb at 48ft per nautical mile above the OCS, or at 200ft per nautical mile for standard OCS, no ODP will be established. Otherwise, an ODP is included with the instrument procedure. The OPD is developed assuming all aircraft engines are in normal operation.

Commonly, ODPs are developed under the assumption that the aircraft will:

• Cross the departure end at least 35 feet above departure end elevation;
• Climb to 400 feet above runway departure end elevation before turning;
• Maintain climb gradient > 200 ft per nautical mile until reaching minimum IFR altitude

References

1. ^ "Chapter 10. IFR Flight". Instrument Flying Handbook (PDF) (FAA-H-8083-15B ed.). Federal Aviation Administration Flight Standards Service. 2012. p. 5.
2. Zimmerman, John (8 November 2021). "It's time to reform Obstacle Departure Procedures". Air Facts Journal. Retrieved 14 January 2025.
3. Wally Moran. "Obstacle Departure Procedures". PilotWorkshops. Retrieved 14 January 2025.
4. Thomas A. Horne (10 January 2016). "On Instruments: Launch rules". AOPA. Retrieved 14 January 2025.
5. Neil Singer (5 May 2013). "Obstacle departure procedures". AOPA. Retrieved 14 January 2025.
6. "IFR Departure - Instrument Proficiency Check Review Guide". Federal Aviation Administration. Retrieved 14 January 2025. This article incorporates text from this source, which is in the public domain.

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