The practice of annotating "NO DP" or "NO SID" in an IFR flight plan remarks section is a legitimate and widely recognized technique, but its application and effect depend critically on which type of departure procedure is being declined. Departure procedures fall into two distinct categories under FAA guidance: Standard Instrument Departures (SIDs), which are ATC-assigned procedures primarily designed for traffic management and route efficiency, and Obstacle Departure Procedures (ODPs), which are pilot-navigated procedures designed specifically to provide obstacle clearance. These two categories carry fundamentally different operational and safety implications, and treating them as interchangeable is a source of persistent confusion in IFR training environments.
When a pilot files "NO SID" in the remarks field of an IFR flight plan, this communicates to ATC that the crew does not wish to be assigned a SID for the departure. This is entirely acceptable and routinely honored by ATC facilities. Reasons vary: the pilot may not have the SID plate available, the aircraft may lack the equipment to comply with all waypoints or speed constraints, or the operator may simply prefer vectored departures for workload management. In response, ATC will typically issue radar vectors, a heading, or a direct routing to an en route fix as part of the IFR clearance. This is standard practice at radar-equipped facilities and presents no significant operational complication in controlled airspace with radar coverage.
The situation changes substantially when "NO DP" is interpreted to mean declining an ODP. ODPs are not assigned by ATC — they are published procedures that pilots are expected to use when no other departure is in effect and no ATC vectors are provided. Under AIM 5-2-8, if a pilot does not file or accept a SID, the expectation is that the applicable ODP will be flown unless ATC explicitly provides an alternative. Notably, ATC does not guarantee obstacle clearance unless the aircraft is being radar-vectored above the Minimum Vectoring Altitude (MVA). At airports with limited radar coverage, non-radar environments, or during periods of radar outage, simply annotating "NO DP" and expecting ATC to absorb the obstacle clearance responsibility is operationally and legally unsound. The ODP exists precisely because those conditions arise.
For professional and instrument-rated pilots operating under Parts 91, 135, or in business aviation contexts, the distinction carries real operational weight. At major hub airports with full radar coverage and robust SID infrastructure, "NO SID" in remarks is a routine coordination tool with minimal risk — controllers expect it and plan for it. At smaller airports, regional fields, or destinations in mountainous or obstacle-rich terrain, the ODP may represent the only published safeguard against controlled flight into terrain during the initial departure climb. Operators flying into unfamiliar airports, particularly at night or in IMC, should verify whether a published ODP exists, whether ATC has radar coverage at departure, and whether the issued clearance explicitly accounts for obstacle clearance before electing to deviate from any published departure procedure.
The broader trend in IFR training — where procedures like "NO DP" notation are taught as simple checklist items — reflects a recurring tension between practical cockpit management techniques and the underlying aeronautical decision-making that makes them safe to apply. Ground school instruction that introduces this technique without fully distinguishing between SIDs and ODPs, or without addressing the radar-coverage dependency, risks producing pilots who know the notation but not its operational limits. As NextGen airspace modernization continues to expand SID and STAR usage at an increasing number of airports, understanding the full scope of departure procedure compliance — not just how to opt out of a procedure, but when doing so is safe — becomes progressively more important for pilots at all certification levels.